iEnvironmental Engineering Researchj
Anaerobic Digestion of Sewage Sludge Incorporating Acidic Thermal Treatment
Masanobu TAKASHIMA* and Yoshihito TANAKA**
*:Dept. for the Application of Nuclear Technology, Fukui University of Technology
**:Technology Division, Hokukon Ltd.
[Masanobu TAKASHIMA ] email@example.com
Acidic thermal treatment was examined with respect to treatment conditions and its efficacy, when incorporated into anaerobic digestion of sewage sludge. In the batch study, the treatment temperature of 25, 100 and 180oC and initial pH of 6, 4 and 2 were applied. Methane production and sludge destruction was improved as the temperature was raised, whereas dewaterability was improved as the pH was lowered. Color was generated significantly at the temperature of 180oC. In the continuous experiment operated at the HRT/SRT of 20 days, the acidic thermal treatment at 170oC and pH5-6 for 1 hour was combined with anaerobic digestion in a post-treatment mode, using hydrochloric acid or sulfuric acid as the strong acid. Compared with the control digestor, the digestor incorporating the acidic thermal treatment showed 1.8-2.0 times more sludge destruction, 13-22% more methane production, 20-32% more dewaterability improvement. A disadvantage was again seen in color generation. Sulfuric acid caused more release of phosphorus from the sewage sludge, which enables efficient phosphorus recovery.
Reduction of alkali addition for treatment of shochu distillery wastewater by pilot-scale thermophilic (55 C) multi-staged UASB reactor
Masayoshi YAMADA*, Tomohito KATAHIRA*, Masahito YAMAUCHI**, Akiyoshi OHASHI* and Hideki HARADA***
*: Dept. of Environmental Systems Engineering, Nagaoka University of Technology, JAPAN
**: Dept. of Civil Engineering, Kagoshima National College of Technology, JAPAN
***: Dept. of Civil Engineering, Tohoku University, JAPAN
[YAMADA Masayoshi] firstname.lastname@example.org
One of the main disadvantages of anaerobic treatment of wastewater having low pH is that the operational cost is too high as there is a need to supply a considerable amount of alkali from outside. To curtail the cost by reducing alkali supply, a sequential multi-feed mode (distributed feeding) and effluent recycle mode were proposed, and verified by conducting experiment on a pilot-scale (2.5 m3) thermophilic (55 C) multi-staged UASB reactor. Wastewater used for the study was alcohol distillery wastewater (shochu), one of the largely produced industrial wastewater in Japan. The sequential multi-feed mode of operation (SMF 5; influent pH: 5.0, COD loading rate: 45 kgCOD_m-3_d-1 (HRT: 12 h, influent COD concentration: 20,900 mgCOD_L-1)), successfully made it possible to lessen alkalinity supplement (24 % NaOH solution) by 67.2 % compared to the single feed mode. As for the effluent recycle mode operation (ER 4; F:W:E = 1:4:10, COD loading rate: 35 kgCOD_m-3_d-1 (HRT: 12 h, influent COD concentration: 17,400 mgCOD_L-1)), operation was possible without any supplement of alkalinity as the system reuses the alkalinity generated during the microbial metabolism.
Biogasification of garbage and waste-paper by hydrogen-methane two-stage fermentation system
KATAOKA Naoaki*, AYAME Shohei**, MIYA Akiko***, YONEYAMA Yutaka*, WATANABE Akira****, SUZUKI Takayuki*****
*:Water Environmental Technology Development Office, EBARA Environmental Engineering Corporation, JAPAN
**:Chemical Sales Planning Office, Ebara Engineering Service Corporation, JAPAN
***:Technologies, Research & Development Division, Ebara Corporation, JAPAN
****:Environmental Technology Development Office, Ebara Corporation, JAPAN
*****:Japan Science and Technology Agency, JAPAN
Bench-scale continuous digestion experiments were conducted with a thermophilic hydrogen-methane fermentation system, composed of a solubilization/hydrogen fermentation reactor and a methane fermentation reactor, using simulated garbage + toilet-paper as raw material. For promoting digestion in the solubilization/hydrogen fermentation reactor, part of the methane fermentation slurry was returned to the solubilization/hydrogen reactor to facilitate pH maintenance and microorganism enrichment. The solubilization and hydrogen fermentation reactor exhibited a biogas production rate of 0.06L/gVS. The hydrogen gas content of the biogas was 25-63%. The methane fermentation reactor exhibited CODCr removal rate of 74%. A semi-pilot scale plant for treating food leftovers and waste paper by hydrogen-methane two-stage fermentation was tested. Pre-treated strong slurry (VS 91,900mg/L) was solubilized and digested under thermophilic hydrogen fermentation conditions of HRT of 2.1 d and recirculation ratio of 0.67. VSS removal rate at pH5.8 was found to be 52%, biogas production rate to be 0.16L/gVS.
Treatment of Low-strength Wastewater by Anaerobic Down-flow Hanging (AnDHS) Reactor
Haruhiko SUMINO*, Ryuichi MUROTA*, Akiyoshi OHASHI**, Hideki HARADA**, Kazuaki SYUTSUBO***
*: Department of Civil Engineering, Gifu National College of Technology, JAPAN **: Department of Environmental Systems Engineering, Nagaoka University of Technology, JAPAN ***: Water and Soil Environment Division, National Institute for Environmental Studies, JAPAN
We investigated performance of a developed novel anaerobic down-flow hanging sponge (AnDHS) reactor for low-strength wastewater treatment. An artificial wastewater of 300-400 mgCOD/L was continuously fed over one year at 2, 4 or 6 HRT. Under the operational conditions at 20, HRT 2 hr and at 15, HRT 4 hr, 70-80 % of total COD removal and 60-90 % of methane recovery were achieved. Regarding operational mode, one through operation gave a better performance in COD removal compared with recirculation mode. The results of batch experiments feeding single substrate of acetate, propionate or sucrose demonstrated that AnDHS reactor is more preferable to very low-strength wastewater and this reactor had a great potential in the volumetric substrate-degrading activitie 2-3 times as large as that in the continuous experiment of restricted substrate concentration. In addition this reactor was faced with no trouble concerning sludge-retainment such as massive loss of sludge by washing through the long experiment over 500 days. This study showed that AnDHS reactor succeeded in high COD removal by methane fermentation without seeding biofilm and was obviously easier in maintenance than conventional anaerobic treatment reactors.
Improvement of anaerobic digestion process with ozonation by thermophilic-mesophilic-phased flowscheme
Kazuya KOMATSU*, Hidenari YASUI*, Yu-You LI**, Tatsuya NOIKE***
*:R&D Division, Kurita Water Industries ltd., JAPAN
**:Graduate School of Engineering, Tohoku University, JAPAN
***:Advanced Research Institute for the Science and Humanities, Nihon University, JAPAN
[Kazuya KOMATSU] email@example.com
The performance of thermophilic (55oC) and mesophilic (35oC) anaerobic digestion with ozonation were evaluated by pilot-scale experiments. Under thermophilic condition, the degradation efficiency of VSS compounds was 5.5% higher (85.3%) than that of mesophilic condition at 0.9-1.0 kgTVS/m3/day and consumption of ozone per decomposed VSS was reduced by 18%. However, the biogas conversion was not improved due to remaining considerable organic fraction in soluble form. This fraction was found to be readily degraded by mesophilic microbes under mesophilic condition. Based on the results, the themophilic-mesophilic-phased digestion process with ozonation, where ozonated sludge was decomposed rapidly in the thermophilic digester and the residual soluble organic fraction in the thermophilic digested sludge was decomposed to biogas in the mesophilic digester, was developed. The new flowscheme performed 8.1% higher TVS degradation efficiency and corresponding more biogas conversion due to improvement of TVS degradation. Ozone consumption in the new flowscheme was 18% lower than mesophilic condition.
Effects of pH and temperature on unsterile thermophilic fermentation with L-lactate cultured broth inoculum
Satoshi AKAO, Hiroshi TSUNO and Taku HORIE
Dept. of Environ. and Urban Eng. Grad. School of ENG. , Kankyo University
In order to expand cultivation conditions of pH and temperature, a series of thermophilic L-lactate batch fermentation experiments of unsterilized garbage was investigated with fermented L-lactate cultural broth inoculum in consideration of semi-continuous operation. The results showed that L-lactate was produced under the set of conditions of pH 6.5 and 50_C with using the inoculation. On the other hand, D-, L-lactate was fermented under the set of conditions of pH 6.0 and 50_C. These conflicting respects would depend on the optimal growth conditions of Bacillus coagulans that is the L-lactic acid bacterium of the thermophilic L-lactate fermentation. The optimal growth condition of B. coagulans was reported at pH 6.5~7.0 and around 50_C. A multiple regression analysis was applied to production of L-lactate on each L-lactate batch fermentation for evaluating effects of pH and temperature. This analysis indicated that decrease in temperature to 50_C and increase in pH to 6.5 would enhance its production in thermophilic L-lactate batch fermentation.
Batch test on the removal of pharmaceuticals by UV treatment
Ilho KIM*, Hiroaki TANAKA*, Naoyuki YAMASHITA*, Yoshikazu KOBAYASHI*,Takashi OKUDA*, Tatsuyuki IWASAKI**, Kiyoshi YOSHINO** and Takeshi TAKUBO**
*:Dept. of Urban and Environmental Engineering, Kyoto University
**:Iwasaki Electric Co.,LTD.
The removal characteristics of pharmaceuticals such as antibiotics and analgesics by ultra-violet treatment were examined. The synthetic raw water of 20L which 30 kinds of pharmaceuticals were spiked simultaneously was injected to the reactor and each experiment was conducted by batch test using 3 kinds of UV lamps. The detection and quantification of each pharmaceutical was done by LC-MS/MS method . It was possible to detect the concentration of each pharmaceutical to order of _/L. The result of batch test showed that the reaction rate coefficient of Cyclophospharmdie, which was not decomposed readily by UV treatment, was most highest in Lamp 1. But, there was no significant difference in the reaction rate of Diclofenac which was a kind of easily-decomposed pharmaceuticals in each Lamps tested.
Evaluation of Toxicity of Pharmaceuticals Based on Algal Growth Inhibition Test
Aya FUKUNAGA*, Naoyuki YAMASHITA*,Hiroaki TANAKA*
*:Research Center for Environmental Quality Management , Kyoto University
In recent years, many studies have revealed the presence of many pharmaceuticals in the water environment. Little information , however, is available about the influence of such pharmaceuticals on aquatic organisms. In this research, we conducted algal growth inhibition test of 55 pharmaceuticals using microplates as a substitute for conical flasks and investigated characteristics of the toxicities of 55 pharmaceuticals. Fifty-five pharmaceuticals had wide-ranging ecotoxicity values (EC50, NOEC, LOEC). The most toxic pharmaceutical of them was triclosan (EC50 = 0.00760 mgEl-1). Comparing with the 55 EC50 values can not demonstrate the relationship between toxicity and physicochemical characteristics of the individual pharmaceuticals but indicate that the toxicities tends to be determined by whether target sites of the individual pharmaceuticals exists in the algae. The tendency was especially found pronounced in antibiotics.
The Occurrence of Pharmaceuticals during Advanced Wastewater Treatment
Yoshikazu KOBAYASHI*, Takashi OKUDA*, Naoyuki YAMASHITA*, Hiroaki TANAKA*, Shuhei TANAKA*, Shigeo FUJII* ,Chie KONISHI** and Isao HOUWA**
*:Research Center for Environmental Quality Management, Kyoto University
**:Murata Keisokuki Service Co., Ltd.
In recent years, water pollution problem by Pharmaceuticals is interested mainly in Europe and U.S.. In this research, we selected 65 compounds of pharmaceuticals as target compounds and we investigated in wastewater treatment plants using advanced treatment. The purposes are to determine the occurrence of pharmaceuticals in wastewater and to determine the behavior of pharmaceuticals during advanced wastewater treatment. As a result, 29 compounds among 65 compounds were detected in the influent by ng/L - Êg/L order and some compounds which has not been detected ever were detected. It was confirmed that each compounds have some removal characteristics during activated sludge treatment process. Moreover, during the treatment process which used chemical coagulants, sand filtration and UV, selected compounds weren't removed too much. But, during ozonation process, almost selected compounds were removed below each limit of detection.
Development of Simultaneous Analysis of Pharmaceuticals in Aqueous Samples Using LC-MS/MS
Chie KONISHI*, Isao HOWA*, Norihide NAKADA**, Koya KOMORI**, Yutaka SUZUKI** ,Hiroaki TANAKA***
*:Murata Keisokuki Service Co., Ltd.
**:Public Works Research Institute
***:Research Center for Environmental Quality Management, Kyoto University
[Isao HOWA] firstname.lastname@example.org
In recent years, pharmaceuticals have attracted attention as new environmental contaminants. Their detections in the aqueous environment thanks to innovative analytical methods have been extensively reported in Europe and North America. The purpose of this study is to develop an innovative and timesaving method to analyze many pharmaceuticals in water samples by solid phase extraction and LC-MS/MS. In this study, the recoveries and the efficiencies of both extraction and ionization were evaluated in comparison with between an absolute calibration curve method and a gstandard addition method at a single concentration.h The results showed that the standard addition method can correct more appropriately measurement values biased due to the extraction and ionization processes. Detection@limits of 58 pharmaceuticals are between 0.66 to 59 ng/l for a concentration factor of 200. Therefore, this method is useful for simultaneous analysis of pharmaceuticals in the aqueous environment.
Removal of NOM and 17 beta-estradiol by Fixed-bed Granular Activated Carbon Columns
LI Fusheng*, TANAKA Hidenori**, KATAMINE Yoshihiro**, YUASA Akira***
*: Department of Civil Engineering, Gifu University
**: Graduate School of Engineering, Gifu University
***: River Basin Research Center, Gifu University
[LI Fusheng] email@example.com
Four granular activated carbon (GAC) columns (GAC-1~GAC-4) were designed by packing two types of GAC achieved by pulverizing and sieving a market-available GAC (F-400/Filtrasorb/USA) into two particle size ranges (d=0.5-0.59mm and d=1.0-1.19mm). In parallel, four biological GAC columns (BAC-1~BAC-4) were also established by coating identical GAC columns with microorganisms detached from the river bed sediment at the river water sampling site. River water containing lower content of NOM was pumped continuously into the columns to examine the behavior of NOM. Besides, 17 beta-estradiol (E2) was intermittently added into the river water with/without the addition of a peat water that contains a high NOM content to investigate the removal of E2 and the responses of all columns to the influent NOM increases. The results after running for about 3000 hours showed that: (1) NOM constituents (excluding non-adsorbable ones) were well removed over the wide range of molecular weights; (2) a portion of DOC species not reflective by UV260 was removed through degradation by attached microbes; and (3) E2 was readily removed via adsorption (for GAC columns) and a combination of adsorption/ biodegradation (for BAC columns), with its removals being significantly higher than those of NOM.
Sorption Characteristics of the Human Antibiotics to Activated Sludge
Makoto YASOJIMA*, Arata HARADA**, Koya KOMORI** and Yutaka SUZUKI**
*:Towa Kagaku Co., LTD
**:Public Works Research Institute
In recent years, pharmaceuticals and personal care products (PPCPs) remaining in water environment have become social problem in many advanced countries. The purpose of this research is to quantitatively evaluate the sorption charasteristics of three human antibiotics (levofloxacin: LVFX, clarithromycin:CAM, azithromycin:AZM) to activated sludge. When batch sorption experimental results were analyzed with the Freundlich model, 1/n of CAM and AZM were almost the same level, while 1/n of LVFX was higher. This tendency was also observed in three component mixed system. The specific amount of sorption per unit equilibrium concentration was in the order of LVFX, AZM and CAM, and this might predict the capacity of activated sludge against these antibiotics. When inactivated sludge was used, equilibrium concentration increased by approximetly 10 times at maximum compared with that for activated sludge. The reason of the increase of the concentration, might be that the microorganism of activated sludge have lost the ability of taking target antibiotics to the inside of the body.
Investigation of PFOS and PFOA in a Wastewater Treatment Plant
Munehiro NOZOE, Shigeo FUJII, Shuhei TANAKA,
Hiroaki TANAKA and Naoyuki YAMASHITA
Research Center for Environmental Quality Management, Graduate school of Engineering, Kyoto University
[NOZOE Munehiro] firstname.lastname@example.org
Few researchers have reported on influent or effluent load and the behavior of PFOS and PFOA, persistent fluorinated organic compounds, in wastewater treatment plants. In this study, water quality and quantity were investigated in a wastewater treatment plant (population: 570,000), in September 2005 and January 2006. Main conclusions obtained are as follows: 1) More than 80% of PFOS and PFOA in an aeration tank were adsorbed to activated sludge and were likely accumulated in a wastewater treatment plant, 2) 84% PFOS decreased in an ultra-advanced treatment by ozonation and biological activated carbon and 3) the flux of PFOS and PFOA were 1.5, 10.0 g/day in influent, 5.6, 12.4 g/day in effluent (flow: 185,000 m3/day), respectively.
Analysis of DNA damage and AhR ligand activity in treated sewage effluent by using HPLC-bioassay
OTOBE Fumiko*, CHOU Pei-Hsin*, MATSUI Saburo* ,ODA Yoshimitu** ,MATSUDA Tomanari*
*:Graduate School of Global Environmental Studies, Kyoto University
**:Dept. of Industrial Health, Osaka Prefectual Institute of Public Health
[OTOBE Fumiko] email@example.com
[MATSUDA Tomanari] firstname.lastname@example.org
In treated sewage effluents, DNA damage toxicity and endocrine disrupting activity have been detected. But the responsible toxic substances have not fully been identified.
In this study, we concentrated treated sewage effluents at Kyoto city by Sep-Pak C18 cartridges and eluted with methanol and acetone. The 50% methanol extract and the 100% methanol-acetone extract were fractionated by HPLC and three bioassays including umu test, a Bacillus subtilis rec-assay and a yeast AhR reporter gene assay were applied to each fraction. The results showed different patterns in three bioassays. By using umu test, the activity of DNA damage toxicity was detected in fractions of the 50% methanol extract. The Bacillus subtilis rec-assay and the yeast AhR reporter gene assay indicated DNA damage toxicity and AhR ligand activity in different fractons of the 100% methanol-acetone extract. Furthermore, Acid Blue 9 classified into acid dye was contained within the 50% methanol extract fraction. But DNA damage toxicity of Acid Blue 9 was not detected by umu test.
Cloning and analysis of trichloroethene reductive dehalogenase gene and its detection by quantitative real-time PCR
Kanji NAKAMURA *, Masahiro MIZUMOTO **, Toshihiro UENO **and Hiroaki ISHIDA **
*:Dept. of Civil and Environmental Engineering, Tohoku Gakuin University
**:Kurita Water Industries Ltd.
Dehalococcoides bacteria dehalogenate chlorinated ethenes such as trichloroethene (TCE), cis-dichloroethene(c-DCE), and vinyl chloride (VC). TCE reductive dehalogenase gene (tceA), is known to be responsible for mainly TCE and c-DCE dehalogenation. We obtained several tceAs by PCR from TCE-contaminated sites in Japan. After DNA sequences of tceAs were determined, phylogenetic analysis was conducted. The genes of tceA obtained in Japan were phylogenetically different from those reported in USA. All tceAs were compared each other and consensus regions were used to design primer pairs and hybridization probes to detect tceA by quantitative real-time PCR (qPCR). The developed method successfully detected tceA in a field where we conducted biostimulation for TCE removal. The increase of tceA concentration in groundwater was well correspond to the decrease of c-DCE. A certain type of tceA was observed at a monitoring well during a whole treatment period.
Acquisition of Algal Genes Coding Proteins Responsible for Coagulation Inhibition Using Phage Display Technique
Daisuke SANO, Tomoko TAKAARA, Takayoshi SUZUKI and Tatsuo OMURA
Dpt. of Civil Engineering, Graduate School of Engineering, Tohoku University
Seasonal overgrowth of cyanobacteria such as Microcystis aeruginosa (M. aeruginosa) is one of serious problems in semi-closed water area including reservoirs. It is known that algogenic organic matters bring about the inhibition of coagulation on the flocculation process in drinking water treatment systems. However, the inhibitory organic matters produced by algae have remained to be elucidated. In this study, phage display library of proteins from M. aeruginosa was used to isolate algal proteins responsible for the coagulation inhibition. Several algal genes coding possible inhibitory proteins were obtained by biopanning using polyaluminum chloride. Amino acid sequences of proteins deduced from the obtained gene suggested that hydroxyl groups in serine and threonine, formamide groups in glutamine and aspargine, thiol groups in cysteine and carboxyl groups in glutamic acid and aspartic acid were involved in the coagulation inhibition. The result of the homology search suggested that metallloenzymes such as glycosyl transferase could be also responsible for the coagulation inhibition.
Analsis of polyhydoroxyalkanoate synthase (phaC) in activated sludge from full-scale waste water treatment plants by cloning method
MICHINAKA Atsuko*, ONUKI Motoharu**, SATOH Hiroyasu*, MINO Takashi*
*:Course of Socio-Cultural and Socio-Physical Environmental Studies, Graduate School of Frontier Science, The University of Tokyo
**:Integrated Research System for Sustainability Science (IR3S) , The University of Tokyo
[MICHINAKA Atsuko] email@example.com
[SATOH Hiroyasu] firstname.lastname@example.org
The phylogenetic diversity of PHA synthase genes (phaC) in activated sludge from three different full-scale wastewater treatment plants was investigated. The PHA synthase genes in activated sludge from three municipal wastewater treatment plants were analyzed by PCR with a C1226f-CPr primer set followed by cloning and DNA sequencing. The clone library from Plant A had a simpler profile, and one of the clones occupied about 50% of the total clones. On the other hand, the clone library from plant N showed higher diversity. When the DNA sequences were translated into amino acid sequences, the similarities of the clones to known PHA synthase were found to be higher than 43%, indicating that the obtained sequences are most probably PHA synthases. The overlaps of the clones from each plant were small, and on the constructed phylogenetic tree, clones from each wastewater treatment plant had a tendency to form their own clusters. Some of the clones were found to have similarities to the known phaC genes to the extent of more than 90%. Some of the clones formed distinct clusters with similarities to the known phaC genes at around 43-49%, indicating the existence of phaC genes not reported from pure cultures.
Visual detection of chromosomal encoded methyl coenzyme M reductase gene of a methanogen by two-pass tyramide signal amplification-fluorescence in situ hybridization (two-pass TSA-FISH) with polydeoxyribonucleotide probes
Shuji KAWAKMI*, Kengo KUBOTA*, Hiroyuki IMACHI*.**, Hideki HARADA*.*** and Akiyoshi OHASHI*
*:Department of Environmental Systems Engineering, Nagaoka University of Technology
**:Japan Agency for Marine-Earth Science and Technology Research Scientist Extremobiosphere Research Center
***: Department of Civil Engineering, Graduate School of Engineering, Tohoku University
[Akiyoshi OHASHI] email@example.com
Applicability and reliability of two-pass tyramide signal amplification-fluorescence in situ hybridization (two-pass TSA-FISH) with PCR generated polydeoxyribonucleotide probes, specific for chromosomal encoded gene, methyl coenzyme M reductase (mcr) in Methanococcus vannielli, was tested and evaluated. The probes were labeled with dinitrophenol (DNP) and the efficiency of probe-labeling was improved by optimizing the concentrations of DNP-labeled nucleotide and Mg2+ in PCR mixture. The target mcr gene was successfully detected, which was again verified by the disappearance of the signals after treating the target with DNase prior to hybridization or washing with high stringency buffer. However, a few nonspecific signals were observed when the method was applied to pure cultures of Methanoculleus bourgensis and Escherichia coli.
PRESENCE OF ANAMMOX PROCESS IN LOW AMMONIUM-FED SOLID-PHASE DENITRIFICATION BIOREACTOR
Bipin K. Pathak*, Futaba Kazama*, and Tatsuo Sumino**
*:Department of Ecosocial System Engineering., University of Yamanashi., Japan
**:Matsudo research laboratory, Hitachi Plant Technologies, Ltd., Japan
[ Bipin K. Pathak] firstname.lastname@example.org
Presence of anaerobic ammonium oxidation (anammox) process was investigated in low ammonium-fed solid-phase denitrification bioreactor. A promising application of solid substrates for denitrification has been appeared since last decade and this type of denitrification here termed as solid-phase denitrification. Bioreactor was operated for 300 days in a temperature-controlled incubator. An immobilized biomass of activated sludge and anaerobic granules was used as inocula in the bioreactor and solid biodegradable plastic as a carbon source. Nitrogen mass balance showed that the average nitrogen removal efficiency in the bioreactor was 80%. The combined results of nutrient profiles, 15N-labelling techniques and qualitative fluorescence in situ hybridization (FISH) probe confirmed that anammox bacteria were active in the bioreactor. This clearly demonstrates that both anammox and denitrification processes work symbiotically in low ammonium concentrations under the support of solid substrates. It revealed that solid substrates not only serve as constant sources of reducing power for denitrification but also creates the favourable condition for anammox process by utilizing dissolved oxygen during the degradation of solid substrates.
Identification of Acetate-oxidizing Bacteria in the UASB Applied to Low Temperature Treatment of Deicing Fluid Wastewater
Takahiro IMAI*, Nobuo ARAKI**, Takashi YAMAGUCHI***and Akihiro NAGANO****
*: Dept. of Civil Engineering, Graduate School of Engineering, Tohoku University
**: Dept. of Civil Engineering, Nagaoka College of Technology
***: Dept. of Civil Engineering, Kure College of Technology
****: Sanki Engineering Co. Ltd.
[IMAI Takahiro] email@example.com, [ARAKI Nobuo] firstname.lastname@example.org
Anaerobic acetate-oxidizing bacteria were identified in the up-flow anaerobic sludge blanket reactor (UASB) applied to the low temperature treatment of sulfate-added wastewater of deicing fluid. Clone library analysis of PCR-amplified 16S ribosomal DNA was employed to identify bacteria, in which acetate was supplied as an electron donor. Identified clones were dominated by those derived from Citrobacter freundii and Desulfomicrobium baculatum in the enrichment culture incubated at 10?C, and those from Clostridium celerecrescens and Desulfovibrio sp. in the enrichment culture incubated at 30?C. Almost all of the cells were detected by FISH analysis using only two kinds of probes specific for hydrogen-utilizing sulfate-reducing bacteria and for either Citrobacter freundii or Clostridium celerecrescens in the both enrichment culture. Those two kinds of bacteria could be an acetate-oxidizing member in each culture.@FISH analysis revealed that Citrobacter freundii, Clostridium celerecrescens and hydrogen-utilizing sulfate-reducing bacteria actually existed in the UASB, and the ratio of them to DAPI-stained total cells were about 2%, 3% and 6%, respectively.
Selective cultivation of benzene degrading microbial consortia under anaerobic condition and their analysis
Nahoko SAKAI*, Futoshi KURISU*, Osami YAGI**, Kazuo YAMAMOTO***
*:Deptartment of Urban Engineering, Graduate School of Engineering, The University of Tokyo
**:Advanced Research Institute for the Science and Humanities, Nihon University
***:Environmental Science Center, The Univercity of Tokyo
[SAKAI Nahoko] email@example.com
Anaerobic benzene degradation is a remarkable tool for bioremediation of contaminated soil and ground water. In this study selective cultivation of benzene degrading anaerobic microbial communities was performed by successive dosing of benzene into soil samples collected from lotus field. PCR-DGGE analysis revealed considerable progressive change in the Bacterial communities whereas negligible change among the Methanogenic Archaea. According the result from 13C6benzene Stable Isotope Probing, some bacteria (mainly in the heavier fraction of 13C-DNA) shared 85% homology in 16S rRNA gene with Syntrophus aciditrophicus SB and Syntrophus gentianae which are known to have symbiotic relationship in anaerobic benzoate degradation. However based on such low homology, the bacteria obtained in this study cannot be certainly identified. This result helps to judge natural attenuation in contaminated soil.
Role of sulfate reduction and sulfur oxidation bacteria on denitrification using of cedar as organic carbon source
Takahiro YAMASHITA*, Ryoko YAMAMOTO-IKEMOTO*
*:Graduate School of Natural Science & Technology, Kanazawa University, JAPAN
[Ryoko YAMAMOTO-IKEMOTO] firstname.lastname@example.org
Sulfate reduction and denitrification using cedar as organic carbon source were examined in an anaerobic biological filter reactor and an anoxic biological filter reactor. In the anaerobic reactor packed with cedar chips, sulfate reduction occurred and bicarbonate was produced. It was estimated that sulfate reducing bacteria utilized cellulose. In the anoxic biological filter reactor packed with ceder chips, nitrate decreased and bicarbonate increased. It was estimated that heterotrophic denitrification mainly occurred in the attached biofilms, although sulfate reducing bacteria coexisted with sulfur denitrification bacteria inside of wood. Microbial community of sulfate reducing bacteria and sulfur denitrification bacteria was examined by a FISH method. Desulfobacter spp. and Desulfonema spp. were most common sulfate reducing bacteria detected in the anaerobic biological filter reactor. In the anoxic biological filter reactor, only Desulfonema spp. was detected in the attached biofilm. Sulfur denitrification bacteria such as Thiomicrospira denitrificans and Thiobacillus denitrificans werenft observed in the attached biofilm.
Development of Quantitative PCR method for Microlunatus phosphovorus and Its Application to Activated Sludge Sample
FUKUSHIMA Toshikazu*, ONUKI Motoharu**, SATOH Hiroyasu*, MINO Takashi*
*:Institute of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo
**:Integrated Research System for Sustainability Science, The University of Tokyo
[FUKUSHIMA Toshikazu] email@example.com
Quantitative PCR method for 16S rRNA gene of Microlunatus phosphovorus was developed utilizing Quenching Primer PCR (QPrimer-PCR). PCR mixture and condition were optimized. Melting curve analysis and sequencing results revealed that only the target M. phosphovorus DNA were PCR amplified, without amplification of the nontarget sequences. We quantified M. phosphovorus in five laboratory-scale enhanced biological phosphorus removal (EBPR) activated sludge processes fed with different carbon sources. The abundance of M. phosphovorus varied according to type of carbon source. In addition, M. phosphovorus existed in full-scale wastewater treatment plants regardless of type of treatment methods.
Composition of microorganisms in ozone-added activated sludge system and treatment characteristics of wastewater by the system
NISHIMURA Fumitake*, UEZUMI Tsukasa*, OKADA Yukiko*, FUJIWARA Taku**, MASUDA Michiko***
*:Deptartment of Civil and Environmental Engineering, Ehime University, JAPAN
**:Deptartment of Environmental Engineering, Kochi University, JAPAN
***:Deptartment of Architecture and Civil Engineering, Nagoya Institute of Technology, JAPAN
[NISHIMURA Fumitake] firstname.lastname@example.org
Ozone-added activated sludge system has been developed for improving treatment operation. Although ozone added activated sludge system was originally developed in order to reduce excess sludge production, it is expected that its direct ozonation to activated sludge system can also remove some biorefractory compounds chemically, and the treatment efficiency and stability can be increased as results. In this study, low ozone loading condition was set, and treatment characteristics of continuous operation and effects of ozone adding on both composition of microorganisms and their biological activity were investigated. Moreover phenol was used as a biorefractory compound in wastewaters and the treatment characteristics were investigated with lab scale experimental setups. It is made clear that direct ozonation to activated sludge within a range of 6.7mgO3/gSS does not inhibit biological activities and biorefractory compound(phenol) can be promptly removed chemically. On the other hand, the experimental case without ozonation can not remove phenol quickly and biological activity is inhibited by existence of phenol. These results suggest that ozone-added activated sludge system can treat wastewaters which contain biorefractory compounds effectively and stably. The possibility is also verified from the ovservation of microorganisms activity, and composition of protozoa and metazoan in continuous treatment.
Contribution of PHA-accumulating Organisms to Acetate Uptake by Activated Sludge Microorganisms
Mamoru OSHIKI*, Motoharu ONUKI**, Hiroyasu Satoh* and Takashi MINO*
*:Inst.of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo
**:Integrated Research System for Sustainability Science, The University of Tokyo
The contribution of PHA-accumulating organisms to acetate uptake was estimated by the batch experiments using activated sludge sample taken from full-scale wastewater treatment plant and dual staining of Nile blue A and DAPI was applied to activated sludge sample in order to evaluate the abundance of PHA-accumulating organisms. The results suggested that 20 to almost 100% of acetate had been taken by the member of Nile blue A positive cells and their population accounted for 10 to 20% in activate sludge incubated under aerobic condition. In order to estimate the contribution of Candidatus ÒAccumulibacter phosphatisÓ and Candidatus ÒCompetibacter phosphatisÓ to acetate uptake, their population were quantified by fluorescent in-situ hybridization (FISH) analysis, and they accounted for 10 to 90% of population of Nile blue A positive cells.
Research of Impact on Road Side Plants of De-icing Salts
KIMURA Keiko*, NAMIKAWA Yoshiharu*, SONE Shinri*
*:Road Environment Division, Environment Department, National Institute for Land and Infrastructure Management, Ministry of Land, Infrastructure and Transport, JAPAN
[KIMURA Keiko] email@example.com
[NAMIKAWA Yoshiharu] firstname.lastname@example.org
[SONE Shinri] email@example.com
[Road Environment Division] firstname.lastname@example.org
In snowy and cold area in Japan, road administrators spread de-icing salts on roads to ensure safe driving in the winter. The quantity of de-icing salts has increased every year since the use of studded tires was prohibited. Some people have expressed their fear that scattering de-icing salts that have been spread damages roadside environments. It is necessary to spread de-icing salts in order to ensure safe driving with minimum harming the natural environment.
So the purpose of this research is to ascertain the relations between de-icing salts and their impact of road side plants. This is a report on surveys of as follows:
- On site experiment to confirm the possibility of the impact.
- On site experiment to clarify spread of de-icing salt.
- Laboratory experiment and document survey to set threshold level.
- On site experiment salinity of roadside soil.
From the results, de-icing salts have little influence on herbaceous plant, so indicators shows under threshold level in spring, summer and autumn, because herbaceous plants are snowy in winter. De-icing salts have possibility to influence trees in from 3 to 5 meters from road edge.
Study of investigation technique for estimation of heavy metal exposure of young children by contact behavior to painted surface
IKEGAMI Maiko IKEGAMI*, YONEDA Minoru*, MORISAWA Shinsuke*
*:Dept. of Urban and Environmental Engineering, Kyoto University, JAPAN
[SAITO Takuya] email@example.com
[YONEDA Minoru] firstname.lastname@example.org
Since paint is being used in various places, it may contain some hazardous heavy metals. If paint becomes old, pieces of paint may peel off easily from the surface of its paintwork. Hence it can be attached onto our hands directly. There is a risk that heavy metals from the paint may enter into the childrenÕs body if children lick their hands. First, actions of young children were observed to estimate the exposure of heavy metals by contacting the paint surface. It was observed that young children licked their hands and put their fingers into their mouth frequently. Next, smear test was conducted and the effects of the materials as well as the frequency of wiping off the paint were studied to evaluate the quantity of heavy metals attached onto the childrenÕs hands or fingers by contacting the paint surface. With the measurement method developed in this study, play sets from a nursery school and playgrounds were examined. The present study indicated that a large amount of Pb was detected, with its maximum value, 4Êg/100cm2. Assuming that young children have a habit of licking thier hands or fingers, the quantity of Pb taken was about 3.2 times higher than TDI.
Leaching Property and Valence Change of Antimony (III) from Intentionally Polluted Soil
SATTA Naoya*, HIKAGE Ikue**, FUKUTANI Satoshi*** and KAMIYA Atsushi****
*:Dept. of Environmental Science, Iwate University
**:The Tohoku Regional Bureau, Minist. of Land, Infrastructure and Transport
***:Research Reactor Institute of Kyoto University
****:Graduate School of Engineering, Kyoto University
[SATTA Naoya] email@example.com
To observe the leaching property and its change in valence from the soil intentionally polluted with trivalent antimony (Sb2O3), extraction tests were performed with pure water and 1M hydrochloric acid (HCl). After three months from the pollution, extracted fractions of Sb were only 0.1 % in pure water and at most 30 % in 1M HCl, respectively. Sb concentrations in pure water leachate were two orders of magnitude lower than solubility of Sb2O3. These results indicated that the antimony was sorbed by soil rapidly and strongly, changed their form into insoluble. Irrespective of leaching solution and initial soil moisture, Sb(V) was the predominant species in soluble fractions.
After three years, Sb(V) concentration in pure water clearly increased, and soluble fraction increased to 0.5 %. The results indicated that aging is one of effective factors on promoting water soluble Sb(V).
INTRACELLULAR SURVIVABILITY OF Legionella pneumophila IN VBNC STATE AGAINST SILVER AND COPPER EXPOSURE
MyoungGoo HWANG, Hiroyuki KATAYAMA, Shinichiro OHGAKI
Department of Urban Engineering. The University of Tokyo
[MyoungGoo HWANG] firstname.lastname@example.org
Eentering into the viable but non-cultivable (VBNC) state in a synthetic drinking water (SDW at 50mL, pH 7.0, and 25oC), the intracellular resuscitation in Acanthamoeba polyphage (ATCC30462), and survivability of L. pneumophila against exposure to silver (AgNO3) and/or copper (CuSO4_5H2O) reagents were investigated in this study. As the results, L. pneumophila completely lost its cultivability after 30 days incubation in SDW, while it maintained its viability (determined by using flow cytometry (FCM) with SYTO 9 and propidium iodide staining) at a nearly constant level (0.1 log reduction) for 190 days. After 4 days co-incubation with A. polyphage (1_105amoeba/mL), L. pneumophila in VBNC state recovered its cultivability and started to resuscitate, and finally grown to 2.55_107CFU/ml after 7 days. The bacteria that resuscitated and multiplied in amoeba was then exposed to silver (0.1mgAg/L) and/or copper (1.0mgCu/L) reagents. All of planktonic L. pneumophila was inactivated completely within 8 hours after injection of silver or copper, but 7.3_103 and 5.6_101CFU/ml of L. pneumophila residing inside of A. polyphage survived against copper and silver exposure even after 7days incubation, respectively. Consequently, the L. pneumophila residing inside of A. polyphage showed much higher tolerance than L. pneumophilia in planktonic state against the same doze of silver and/or copper, and this phenomenon was explained by the amoeba interruption to chemisorption of disinfectant onto bacteria residing inside of amoeba.
Risk evaluation for waterborne infectious diseases in the Mekong watershed considering water supply systems
WATANABE Toru*, MIURA Takayuki*, SASAKI Tsukasa*, NAKAMURA Satoshi**, OMURA Tatsuo*
*: Department of Civil Engineering, Graduate School of Engineering, Tohoku University, JAPAN
**: Research Institute, International Medical Center of Japan, JAPAN
[WATANABE Toru] email@example.com
In the Mekong watershed, for reducing the infectious risk, the provincial water supply (PWS) system composed of the water treatment plant and the distribution system has been installed in big cities. The village water supply (VWS) system for distributing the groundwater to villagers without any treatments has been also provided. In order to estimate effects of these water supply systems on reducing the infectious risk, two case-studies for evaluating the risk of infectious diseases associated with the drinking water were conducted. In the case-study in Thailand, the geometric mean of infectious risk in the area with the PWS system was less than one-eighth of that in the area with the VWS system. This result means that the chlorine disinfection of the tap water in the PWS system would contribute to the reduction of infectious risk. In the other case-study in Cambodia, the geometric mean of infectious risks in areas with the VWS system was about five times lower than that in the area without access to water supply. Therefore it was expected that the infectious risk could be reduced by the construction of the VWS system in the area without access to water supply.
Establishment of Norovirus detection method from wastewater sample
SUYAMA Akiko*, **, SUWA Mamoru**, SUZUKI Yutaka***, OZAKI Masaaki**
*:TOWA KAGAKU Co., Ltd.
**: Public Works Research Institute, Material and Geotechnical Engineering Research Group
***: Public Works Research Institute, Water Environment Research Group
[SUWA Mamoru] firstname.lastname@example.org
The aim of this study is to adapt techniques of molecular biology (real-time reverse transcription-polymerase chain reaction (RT-PCR)) to Norovirus detection methods due to the importance of developing a rapid and highly sensitive method for quantitative detection of Norovirus from wastewater. We evaluated the efficiency of the Norovirus detection method for the following processes: 1) Various collection and elution methods, 2) Clarification of sensitivity and detection limit values, 3) Optimization of the collection sample volume suitable for the sewage influent sample, and 4) Optimization of the reverse transcription efficiency of the extracted Norovirus RNA. From the results, for the polyethylene glycol precipitation method, collection and elution methods were investigated and suitable methods for influent, effluent and tertiary effluent were proposed. In the polyethylene glycol precipitation method of inflow sewage, a high collection ratio was observed at the sample volume of about 10 ml. The reverse transcription efficiency was increased by adjusting the addition concentration of primer and RNA. The concentration of the Norovirus cDNA of a necessary 10 copies per reaction tube to obtain a stable value measured by the real-time RT-PCR method was clarified.
The effect of neutralization with carbon dioxide on leaching amounts of
heavy metals from cement solidified waste of municipal incineration fly ash
Takao YAMADA*, Yoshinori KANJO*, Hiroaki SAIKA*, Mukedes ABUDURISHIT*, Yoshiro ONO**
*:Graduate School of Engineering, Osaka City University
**:Graduate School of Engineering, Okayama University
Reduction characteristics of Cr, Cu, Pb and Zn leaching from cement-solidified MSWI fly ash by neutralization were studied. Carbon dioxide was contacted to the cement solidified material, and the relationship between contacting time and pH changes of the material are described. The test method using phenolphthalein was proposed, in order to get the neutralized condition of material. Furthermore, the tank leaching test was performed to the alkaline material and completely neutralized material, and the leaching flux of Pb, Zn, Cu and Cr from both materials are compared. The leaching flux of Pb, Cr and Cu decreased by neutralization. On the other hand, Zn leaching amount increased because pH of the material was considered too low. Keeping the neutralized levels of the cement solidified waste is important to reduce the leaching amount of the heavy metals.
The Chemical States of Virgin and Kneaded Ash with Chelating Agent
YAMAMOTO Hiroshi *, NAGOSHI Masayasu **, YOKOYAMA Takashi ***, TAKAOKA Masaki **** and TAKEDA Nobuo ****
*: JFE R&D Corporation@
**: JFE Steel Corporation@
***: JFE Engineering Corporation@
****: Dept. of Urban & Environmental Engineering, Kyoto University
[YAMAMOTO Hiroshi] email@example.com
The changes of chemical states for Pb in virgin and kneaded fly ash with chelating agent were investigated by using XAFS spectroscopy at beam line BL01B1 in SPring-8. The precipitate prepared from a chelating agent of marketing and a lead chloride solution has the same chemical state as the lead chelate complex which prepared from potassium diethyldithiocarbamate and lead chloride solution. Thus it was comfirmed that the chelating agent was able to form a lead chelate complex with Pb2+ ion. The chemical form of the lead chelate complex and Pb in kneaded fly ash were the same chemical state by XANES and EXAFS spectra, thus it was verified that the kneading process of fly ash with chelating agent was able to form lead chelate complex. Even when the chemical state of Pb in a fly ash differed, it became clear that the same lead chelate complex generated by kneading processing with a chelating agent.
Influence of Organic Matters on the Elution of Chroline in Municipal Solid Waste Bottom Ash
TAKEMOTO Tomonori*, SHIMAOKA Takayuki**, ETOH Jiro***, NARUOKA Tomohiro***
*:Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, JAPAN
**:Department of Urban and Environmental Engineering, Faculty of Engineering, Kyushu University, JAPAN
***:Institute of Environmental Systems, Kyushu University, JAPAN
[TAKEMOTO Tomonori] firstname.lastname@example.org
[SHIMAOKA Takayuki] email@example.com
An experimental study was conducted to investigate the ability of municipal solid waste bottom ash as a material of Portland cement. Bottom ash contains large amount of chlorine and insoluble chlorine such as Friedelfs salt in bottom ash has remained as a problem. If bottom ash is mixed with compost, it is expected that Friedelfs salt will be decomposed in a low pH environment, which is caused with acids such as organic acids, the sulfuric acid ion, the nitric acid ion, and the nitrous acid ion which are generated by organic matters decomposed, because Friedelfs salt has a high solubility in a low pH less than 11.
In this study, the mixture samples of bottom ash and compost (leaf mould compost, sewage sludge compost, and garbage compost) were tested to clarify influence of organic matters on the elution of chlorine in bottom ash. The pH and the content of chlorine in the mixture samples of bottom ash and compost decreased more than in the samples of bottom ash. The content of chlorine in the mixture samples decreased under 0.2 wt.% after 54 weeks. As a result of XRD, main peak of Friedelfs salt decreased according to decrease of insoluble chlorine.
Leaching and restraining of heavy metals from foaming glass recycled from waste glass
Hideyuki MONGI*, Yurie YAMAMURA**, Takanori KISHIMOTO* and Yosihiko HOSOI***
*:Tottori Prefecture Institute of Public Health and Environmental Science
**:Life Environment Department,Public Parks and Natural Environment Division,Tottori Prefecture Government
***:Department of Social Systems Engineering ,Tottori University
The environmental safety of foaming glass that is made from waste glass was examined. The foaming glass is made by adding silicon carbide to crashed waste glass and being foamed with high temperature.The contents of Pb, As,Cr in a waste carboy and their amount in a leachate from an experimentally made glass were analyzed. As a result, the concentrations of Pb As, and Cr in the waste carboy were 100(23 _ 190) mg/kg, 11(4.0 _ 25)mg/kg, and 840(810 _ 1000)mg/kg, respectively. Green glass had high concentration of all the metals. The concentration of the metals in the leachate was as follows, Pb:0.15(<0.01 - 0.43) mg/l, Cr (IV): 0.11(<0.05 - 0.33)mg/l, and As: 1.2(0.43 _ 3.1)mg/l.The leaching of Pb from foam glass could be effectively restrained by adding CaSO4 or Fe2(SO4)3 to the raw materials, while the leaching of As could be restrained by adding Ca(OH)2 and Fe2(SO4)3.
Numerical study of waste temperature distribution within a sanitary landfill where a high temperature rise exists
YOSHIDA Hideki *, HOZUMI Hitoshi *
*:Dept. of Civil Engineering and Architecture, Muroran Institute of Technology, JAPAN
[YOSHIDA Hideki] firstname.lastname@example.org
[HOZUMI Hitoshi] email@example.com
This study examines waste temperature distribution within the Tokyo Port Landfill where a maximum temperature rise as high as 66C exists. Heat and water transport within a sanitary landfill is modeled and the process of the placement of successive waste layers is considered. Spatial and temporal temperature distributions are simulated to validate the model. The model results with different scenarios of decomposition within the landfill are shown to be in good agreement with observed data. Sensitivity analyses in terms of decomosition shows that active aerobic decomposition at the surface of waste layers during landfilling and successive anaerobic decomposition after the completion of landfilling could result in high waste temperature.
Characteristics of heavy metals elution from anaerobically digested sewage sludge with oxidizing reagents
ITO Ayumi*, GOTO Hiroyuki**, TAKAHASHI Kenta***, AIZAWA Jiro**** and Umita Teruyuki****
*:Dept. of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, JAPAN
**:Kurita Water Industries Ltd., JAPAN
***:Dept. of Civil and Environmental Engineering, Graduate School of Engineering, Iwate University, JAPAN
****:Dept. of Civil and Environmental Engineering, Iwate University, JAPAN
[ITO Ayumi] firstname.lastname@example.org
The characteristics of heavy metals elution from anaerobically digested sewage sludge with oxidizing reagents were investigated by applying hydrogen peroxide, ferric sulfate or their combination to the sludge under acidic conditions. The application of both hydrogen peroxide and ferric sulfate accelerated the elution of Cd, Cu and Zn from the sludge and remarkably improved the elution efficiency of Cu at pH 2.
Heavy metals in the sludge were fractionated into three organically bound forms associated with water-soluble proteins, fat-soluble ones and extracellular polymers and residual one. The contents of Cu in the organically bound forms associated with fat-soluble proteins and extracellular polymers and the residual form were significantly decreased after the metals elution process with ferric sulfate and hydrogen peroxide at pH 2. These results showed a possibility that hydroxyl radicals produced in the Fenton reaction promote the elution of Cu from the sludge.
Demonstration test of accelerated stabilization of coastal reclamation waste disposal model reactor appling leachate circulation
SEI Kazunari*, UCHIKAWA Yumi*, NGUYEN N. Sang*, IKE Michihiko*, FUJITA Masanori*,**, ISHIGAKI Tomonori***,****, INANC Blent****, INOUE Yuzo****, MITSUI Kiyoshi*****, MAEDA Shin-ichi*****, SUZUKI Manabu******, KADOKAMI Kiwao******, KOEZUKA Takao******
*:Division of Sustainable Energy and Environmental Engineering, Osaka University, JAPAN
**:Kochi National College of Technology, JAPAN
***:Department of Environmental Solution Technology, Ryukoku University, JAPAN
****:Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, JAPAN
*****:Aqua Research Center, Kitakyushu City Institute of Environmental Science, JAPAN
******:Hibikinada Developmemt Co., Ltd., JAPAN
[SEI Kazunari] email@example.com
Leachate recirculatory semiaerobic landfilling, one of the accelerated stabilization technology of landfill was evaluated on the applicability to coastal reclamation waste disposal based on the water quality of leachate and on the behavior of microorganisms using model reactor. Accelerated degradation / removal of organic carbon and nitrogen was confirmed. Especially both ammonium oxidizing and denitrifying bacteria coexisted in the top layer of the reactor seemed to contribute to accelerated stabilization. Thus, leachate recirculatory semiaerobic landfilling must be a certain technology for accelerated stabilization of coastal reclamation waste disposal, which can stimulate the microorganisms responsible for the degradation / removal of organic carbon and nitrogen. As there are only a few reports on the microbial community structure in landfills or leachate, further accumulation of the data is essential and will show the typical microbial community for the suitable organic compounds decomposition, nitrogen removal, and for the process control.
EFFECT OF ANAEROBIC SRT ON COMPLETE PHOSPHATE REMOVAL IN A POST-DENITRIFICATION SYSTEM
Vladimir TORRICO*and Takahiro KUBA*
*Graduate School of Urban and Environmental Engineering, Kyushu University, JAPAN
A continuous flow post-denitrification (Dephanox type) lab-scale system fed with raw wastewater was operated in order to investigate the effect of the anaerobic solids retention time (anaerobic SRT) on phosphate removal. The presence of an internal settler just after the anaerobic tank enhanced the anaerobic SRT. Additional enhancement was provided by accumulation of solids into the internal settler under extreme operational conditions that seemed to be optimal for nutrients removal. Batch experiments with Dephanox sludge showed that the particulate COD fraction contributed with an additional 50% of phosphate release, thus an additional VFAs production can be inferred. In the case of the Dephanox sludge, the enhanced anaerobic SRT assisted effectively to achieve complete phosphate removal. As reference, the same batch experiments with AO and A2O sludge from a full scale plant fed with primary effluent were carried out. The results showed that particulate COD fraction did not contribute significantly on the VFAs production. The combination of long SRT and abundant particulate COD apparently promoted fermentative organisms and denitrifying phosphorus accumulating organisms (DN-PAOs) acting in a syntrophic association on phosphorus removal.
Uptake of Organic Matter by EBPR Activated Sludge under Exposure of Surfactant in Anaerobic Condition
Koji TSUJI*, Masafumi FUJITA* and Hiroaki FURUMAI**
*:Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
**:Graduate School of Engineering, The University of Tokyo
[Masafumi FUJITA] firstname.lastname@example.org
Firstly, phosphate release activity test in which commercial laundry detergents and LAS were added to an actual anaerobic aerobic activated sludge showed the increase of phosphate concentration and PHA content, and subsequent phosphate uptake activity test exhibited the remarkable decrease of phosphate concentration. Therefore, surfactant was likely to be finally accumulated as PHA. Secondly, the adsorption amount of LAS to actual anaerobic aerobic activated sludge in anaerobic tank as well as a daily change in LAS concentration of influent wastewater were examined, so that the adsorption amount of LAS in a lab activated sludge which has never been exposed by any surfactant was adjusted to the actual level by adding detergent including LAS and AE, and sole LAS. Finally, phosphate release test was conducted using the adjusted activated sludge to investigate the effect of surfactant on acetate uptake by polyphosphate-accumulating organisms. The addition of the detergent brought the increase of acetate uptake rate and the decrease of +¢P/-¢Ac value. On the other hand, the addition of the sole LAS caused respective opposite effects. In other words, LAS
decreased acetate uptake rate and its energy efficiency, while AE would increase them.
Effects of Temperature and Ammonium Concentration on Partial Nitrification in Sponge-Airlift Reactor
Kenichi ABE*, Akiyoshi OHASHI*, Hiroyuki IMACHI**, Hideki HARADA***,
*:Dept. of Environmental Systems Engineering, Nagaoka University of Technology
**:Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
***: Dept. of Civil Engineering, Graduate School of Engineering, Tohoku University
****: Kurita Water Industries LTD.
[Kenichi ABE] email@example.com
Three airlift reactors with sponge-carriers were operated by a stepwise increase of ammonium loading rate at different temperatures, 25, 30, 35_C, to investigate effects of temperature and ammonium concentration on partial nitrification to nitrite. A high ammonium loading rate (1 kg NH4+-N¥m-3¥day-1) caused nitrite accumulation accompanied with remaining ammonium. The ratio of nitrite accumulation to ammonium oxidation strongly correlated with free ammonia more than ammonium concentration or temperature. The free ammonia concentration of 8 mg NH3¥L-1 allowed the almost occurrence of partial nitrification having the ratio of 0.8. The result suggests free ammonia must be a crucial factor to control partial nitrification. Cloning results of sludge samples showed Nitrospira genus of nitrite-oxidizing bacteria was a predominant microorganism under the complete nitrification condition, while ammonia-oxidizing bacteria predominated under the partial nitrification condition.
Development of low strength wastewater treatment under low temperature conditions by combining of UASB and DHS reactor system enhancing a sulfur-redox cycle action
Masanobu TAKAHASHI*, Takashi YAMAGUCHI**, Haruhiko SUMINO***, Nobuo ARAKI****, Shinichi YAMAZAKI+, Akihiro NAGANO++, Kazuaki SYUTSUBO+++ and Hideki HARADA++++
*: Environment Tech Co. Ltd., JAPAN
**: Dept. of Civil Engineering, Kure College of Technology, JAPAN
***: Dept. of Civil Engineering, Gifu College of Technology, JAPAN
****: Dept. of Civil Engineering, Nagaoka College of Technology, JAPAN
+: Dept. of Civil Engineering, Kochi College of Technology, JAPAN
++: Enviroment System Division, Sanki Engineering Co. Ltd., JAPAN
+++: Water and Soil Environment Division, National Institute for Environmental Studies, JAPAN
++++: Dept. of Environmental System Engineering, Nagaoka University of Technology, JAPAN
[YAMAGUCHI Takashi] firstname.lastname@example.org
The objective of this research is to make a novel wastewater treatment process activated by a sulfur-redox cycle action of microbe in low temperature conditions. This action is carried out by sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). The reactor system was comprising of an UASB reactor as pre-treatment and an aerobic downflow hanging sponge (DHS) reactor as post-treatment. As the results of reactor operation, the whole process achieved that over 90% of CODcr removal efficiency, less than 35 mg-CODcr/L (less than 20 mg-BOD/L) of final effluent, at 12 hr of HRT and at 8 _C of UASB reactor temperature. As the result of the effect of temperature methane-producing activity (MPA) and sulfate-reducing activity (SRA) of sludge retained in the UASB reactor, below the 25_C condition, SRA was greater than MPA from acetate and H2/CO2 as test substrate. And that MPA was all but destitute at 15_C, SRA was certain despite at 5_C. The proposed sulfur-redox action process was considered as an applicable process for low strength wastewater treatment in low temperature conditions.
Economic examination on waste water treatment system in an industrial park
contributing to local economy
Yoshihiko HOSOI*, Hideki NADA2**, Atsushi KOIKE* and Takanori MASUDA*
*:Dept. of Social Systems Engineering, Tottori University
**:Sakaiminato City Office
The wastewater treatment system of an industrial park where there are major industries that significantly contribute to the local economy was studied. The cost of wastewater treatment affects not only economies of the major industries themselves in the industrial park but also other economic activities in the region. In this study, a local economic model that includes the major industries which are fishery firms, other firms and households was constructed. The effect of the cost of wastewater treatment of the industrial park on local economy was examined by using the economic model. Three possibilities, namely centralized treatment, in which industrial wastewater is collected by pipeline and treated at a central treatment plant, discharge into public sewerage and treatment by each firm, were evaluated. The centralized treatment was found to be the best option from economical as well as environmental point of view.
Study on the modelling of photocatalytic decomposition of organic matter in bacth reactor
Nobuhito YASUI*, Naoyuki KAMIKO**
*:Department of Urban and Civil Engineering, Graduate school of Science and Engineering, Ibaraki University
**:Department of Urban and Civil Engineering, Faculty of Engineering, Ibaraki University
[Naoyuki KAMIKO] email@example.com
Recently, the photocatalyst is attracting attention in various fields. However, there are few studies that investigated guantitatively capacity or effect of photocatalyst. The evaluation method of photocatalytic reaction has not been established. The organic matter decomposition experiment was performed in this study, using a batch type reactor as experimental reactor. The quartz beads coated with thin film of TiO2 as photocatalyst were used. The light source used in the experiment was the black light (BL, 15W). Methylene blue was used as representative of organic matter. From experimental results, the reaction mechanisms of the organic matter decomposition by photocatalytic reaction could be expressed by the model equation, and the rate constant of the used photocatalyst was able to be calculated concretely.
Study on the Water Quality Purification Properties of the Functional Foamed Waste Glass
TANAKA Kenta*, ARAKI Hiroyuki**, YAMANISHI Hiroyuki**, MATSUO Yasunari*, ATAKA Susumu*, MATSUSHITA Atsushi*** and MISHIMA Yuichiro***
*:Technical Research Institute, Nihon Kensetsu Gijutsu Co.,Ltd.
**:Institute of Lowland Technology, Saga University
***:Graduate School, Saga University
[TANAKA Kenta] firstname.lastname@example.org
This study investigates the water quality purification properties of three functional foamed waste glasses (foamed waste glass (FWG), zeolitized FWG and Mg-type FWG) through the batch type adsorption test and the continuous flow test. As a result, it can be proved that these functional foamed waste glasses have high properties of water purification in the removal of SS, BOD, nutrient and heavy metal. Moreover, each of these glasses has its own function in waste removal property, and can be applied to water quality purification systems in rivers, pond and reservoirs.
Application of crushed roof tiles to slant soil layer method
SAITO Takuya *, TOKUNAGA Ryohei **, YONEDA Minoru*, MORISAWA Shinsuke*, ARAI Takashi***
*:Dept. of Urban and Environmental Engineering, Kyoto University, JAPAN
**:Matsusita Electric Works, Ltd., JAPAN
***: Kokuyo Corp., JAPAN
[SAITO Takuya] email@example.com
[YONEDA Minoru] firstname.lastname@example.org
Experiments were executed to make clear the effectiveness of crushed roof tiles as the packing material of slant soil layer method. The following conclusions were obtained from the results. 1) Aerobic reaction could happen more actively in the case using crushed roof tiles than in the case using Akadama soil or Kanuma soil. 2) The reaction could happen at about 10 degrees Celsius. 3) The removal of ammoniac nitrogen and phosphoric acid phosphorous was mainly caused by absorption. 4) The nitrogen and phosphorous removal ability of Akadama soil and Kanuma soil was superior to that of crushed roof tiles. 5) A high denitrification ability of a slant soil laiyer could be obtained by adjusting the particle size of crushed roof tiles. Therefore, it is possible to make an advanced sewage treatment slant soil layer system by combining some types of slant soil layers.
Study on Optimum Process of Resource Recovery from Sobubilized Excess Sludge Treated by Subcritical Water Process Combined with MAP and UASB Method
ARAKANE Mitsuhiro*, IMAI Tsuyoshi*, MURAKAMI Sadaaki**, TAKEUCHI Masami**, UKITA Masao*, SEKINE Masahiko*, HIGUCHI Takaya*
*:Graduate School of Science and Engineering, Yamaguchi University, JAPAN
**:Dept. of Chemical and Biological Engineering, Ube National College of Technology, JAPAN
[IMAI Tsuyoshi] email@example.com
A new process, in which subcritical water process was applied to hydrolyze and solubilize the excess sludge whereafter phosphorus and methane were recovered by MAP and UASB method respectively, was developed by our research group. It was confirmed feasible that phosphorus and methane could be recovered by MAP and UASB process respectively from the solubilized excess sludge. However, there was no information that the difference in the recovery rates of phosphate and methane had occurred by changing the sequence of MAP and UASB process. In this study, the optimum process of phosphorus and methane recovering with MAP and UASB method from solubilized excess sludge was investigated. According to the experiments results, the optimum resource recovery process were in the sequence of UASB and then MAP method.
Influence of the Coagulated Sludge Characteristics with Ferric Chloride on the Phosphate and Coagulant Recovery Process
Kazuyuki OSHITA*, Hiroyuki KITAKOJI**, Fumitaka KATO*, Masaki TAKAOKA*
Nobuo TAKEDA*, Tadao MATSUMOTO* and Ryoichi HIMONO***
*:Dept. of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University
**:Chugai Ro Corporation, Ltd.
***:Osaka Prefecture, Eastern Regional Sewerage Office
Removal of phosphate in wastewater is very important because it causes the eutrophication of the lake or pond. On the other hand, phosphate recovery from sewage and sludge treatment systems is particularly important because it is a limited resource and a large proportion of the phosphate currently used in Japan must be imported. Therefore, we have been experimentally evaluating phosphate and coagulant recovery methods from pre-coagulated sludge with NaHS.
In this study, we experimentally investigated the influence of the coagulated sludge characteristics with ferric chloride on its phosphate and coagulant recovery process. The phosphate extraction and recovery from pre-coagulated sludge with various amount of FeCl3, the iron dissolution using HCl and the oxidation with H2O2 experiments were conducted.
As the result of phosphorus extraction experiment, we found that the increase of FeCl3 dose led to high phosphorus extraction ratio because of the increase of FePO4 in sludge and not extracted phosphorus could exist with Al, Ca and organic matter. In phosphorus recovery experiment, we could obtain good recovered materials which contained 15% of phosphorus and little heavy metals. And as the result of coagulant recovery experiment, recovered coagulant is as effective as commercial FeCl3.
Modeling of an Activated Sludge Process Without Excess Sludge Production Using Indicator from ATP Analysis of Sludge
Yasunori KOSAKI*, Takashi SAKAKIBARA**, Tetsuo KIKUGAWA***, Shinsuke KASAHARA***, Munetaka ISHIKAWA***
*:Eco Solution Net Corp.
**:Matsushita Environmental Air Conditioning Eng. co. Ltd.
***:Dept. of Environmental Engineering, Osaka Institute of Technology
In this work, we used modeling by ATP concentration of sludge as an indicator in order to classify sludge converted into substrate by ATP analysis of sludge, then comparing the examination results with those obtained by simulation of excess sludge in the activated sludge process.
As a result: (1) By assuming that extinction sludge is not detected by ATP, converted sludge was classified into activated sludge, extinction sludge and soluble matter. Then a gConversion to substrate and biodegradation of sludgeh model was developed using an indicator from ATP analysis of sludge. (2) The concentration ratio of activated sludge and extinction sludge in suspended matter was clarified by analyzing the ATP concentration of sludge that was converted to substrate by an ultrasonic processing reactor. The concentration ratios of the three components in converted sludge were estimated by adding the soluble matter concentration. (3) Simulated values obtained from the model based on applying the concentration ratios of converted sludge following ultrasonication were consistent with the results obtained from continuous experimentation. Therefore, the gConversion to substrate and biodegradation of sludgeh model is considered available for analysis of activated sludge process without excess sludge production. (4) On simulation of this model by ultrasonication, the reduction ratio, water quality of effluent and ratio of extinction sludge in the aeration tank could be estimated by setting parameters of MLSS, the concentration ratio of the converted ratio under the various operation conditions.
Effect of operational conditions on the sludge solubilization by the simultaneous use of ultrasonic and electrolytic processes
Tomohide WATANABE*, Dao-Yong ZENG*, Kaori TSUCHIYA* and Kyung-Jin CHO**
*: Dept. of Civil Engineering, Gunma University, Japan
**: WIILTECH Co., Ltd, Korea
[Tomohide WATANABE] firstname.lastname@example.org
Fundamental performance and effective operation of the sludge solubilization treatment by the simultaneous use of ultrasonic and electrolytic processes was investigated experimentally. A lab-scale diaphragm cell irradiated with ultrasound at a constant oscillating frequency of 20 kHz was used as a reactor. The batch experiments were carried out under different electric outputs of the ultrasonic generator, electric currents for the electrolysis and initial SS concentrations. The simultaneous use of ultrasonic and electrolytic processes accelerated soluble COD generation and reduced the specific energy consumption, compared to sonication alone. The pH adjustment of the sludge to a moderate alkaline condition as a pre-treatment further contributed to the improvement of the solubilization performance in the simultaneous use. Such solubilization treatment effectively performed under the conditions below 400 W/L of the ultrasonic density and below 30 g/L of the initial sludge concentration within the experimental range in this investigation. The soluble components in the solubilized sludge had higher a content of readily biodegradable substrates than that by the sonication alone.
Effect of phosphate, ammonia and pH on the degradation of antibiotics in the composting toilet
Takashi KAKIMOTO*, Naoyuki FUNAMIZU*
*:Division of Built Environment, Graduate School of Engineering, Hokkaido University email@example.com
In this study, the fate of three kinds of antibiotics (Tetracycline, Azithromycin, Levofloxacin) and factors affecting their degradation in the composting toilet were investigated. The result indicated that the concentration of Tetrecycline and Azithromycin declined, but Levofloxacin was not degraded in the composting process. To know the factors affecting the degradation of these antibiotics in the composting process, effect of bacterial consumption of antibiotics was evaluated by comparing the ordinary toilet matrix with the sterilized one , and it was found that biological effect can be negligible. Then we evaluated the effect of HPO42-, NH3 and OH- ions by determining each ionic degradation rate constant, by comparing the experimental degradation profiles and simulated ones. This revealed that the degradation of Tetracycline and Azithromycin were affected by the concentration of HPO42- and OH- ions in the composting toilet.
Drying characteristics of sawdust matrix in the dry composting toilet
ITO Ryusei, OGAWA Shingo, FUNAMIZU Naoyuki
Division of Built Environment, Graduate School of Engineering, Hokkaido University
[ITO Ryusei] firstname.lastname@example.org
Drying of the mixture of human waste and sawdust is an essential process for the dry composting toilet system, because moisture content, that is an important factor for biodegradation process, should be kept around 65%. The drying rate is required for design of the system and planning an operation policy with stable operation, but the rate for the system has never been studied. So, we investigated the effect of operational conditions on the drying rate using two devices of different size, lab-scale equipment and full-scale toilet for one personal use. As a result, the drying rate is described by a drying kinetic model with adequacy calibration of water-vapor pressure at the drying surface for each device. The coefficient of full-scale toilet is estimated from the result of lab scale equipment considering the circulation air flow. Then, the drying rate could be estimated from operational conditions for simple design and planning an operation policy of the composting toilet system from the view point of drying.
Estimation of Habitat Suitability in Hakata Bay
Fukuoka Institute of Health and Environmental Sciences
In this paper, a calculation module to determine the habitat suitability based on DO concentration was introduced into an ecosystem model. This was done in order to generate habitat suitability maps of Hakata Bay and reveal the temporal and spatial variations of habitat suitability in the bay.
From the results, it was estimated that the upper water layer of Hakata Bay was a stable zone for habitat suitability from April 2001 to March 2002.On the other hand, in the same period, lethal zones were found in the lowest water layer, such as two hollows near the mouth of Muromi River and the waterways toward the quays, which were locally deeper than the surrounding areas. These lethal zones expanded into the neighboring areas around them in the summer and disappeared in the winter.According to data on animal trafficability, these results indicate that most fish can escape from the oxygen-deficient water to the upper water layer, which has a high DO; however, benthos, which have a low trafficability, are damaged in the lethal zones.
The thriving and declining factors of seaweed beds in the Kumano-Nada
MORI Shoichi*,KUMAGAI Akio*,KANAZAWA Tsuyoshi**
*:Mori Institute of Ecology CO.,LTD.
**:Toyo Construction CO.,LTD. Technical Research Institute
[MORI Shoichi], [KUMAGAI Akio] email@example.com, [KANAZAWA Tsuyoshi] firstname.lastname@example.org
Field observation of the distributions of marine algae and herbivores,the feeding rate of herbivores, water temperature and waves velocity were carried out to analyze the thriving and declining factors of seaweed beds. As for the maximum and minimum water temperatures,the minimum water temperature especially rose at 2-3 in 1970's. It was suggested that the rising water temperature was one of the important factors to depress the germination and growth of marine algae,and resulted to the decline of seaweed bed. In addition ,feeding pressure of Diadema setosum accelerated declining and disturbing a recovery of seaweed beds. In the declining areas of seaweed beds,water current on the sea bottom in August was slower(0.1m/s to 0.5m/s) or faster(0.7m/s to 1.8m/s) than that in thriving area. The sea bottom current of the significant wave in thriving areas was averagely from 0.5m/s to 1.1m/s in August.
Possibility of Practical Use of Datum Observed by Simple Fishing Gears on
Agricultural Canals in Yatsu Paddy Fields
TAKEMURA Takeshi*, KOIZUMI Noriyuki*, OKUSHIMA Shuji*,MORI Atushi*
*: Dept. of Rural Environment, National Institute for Rural Engineering, JAPAN
[TAKEMURA Takeshi] email@example.com
Datum observed by using simple fishing gears are generally supposed to be not suitable for grasping individual distribution. On the other hand, it is not realistic for limited specialists to perform detailed investigation over the country. It is significant to pursue the possibility of analyzing like above mentioned datum.
We have performed investigation of field gudgeon individuals distribution by using simple fishing gears and measured water depth, type of flow-condition and vegetation density on agricultural canals in Yatsu paddy fields of Shitada-gawa River basin, Chiba Prefecture. HSI, Habitat Suitability Index, for field gudgeon of the River basin were already-known. These HSI were developed using datum observed by using an electrochocker. We applied datum observed by using simple fishing gears to those HSI. In result, ranking of numbers of captured individuals seemed to be fit to HSI curves comparatively. Besides, there were strong relationship between above mentioned ranks and values of CSI, Composite Suitability Index, culculated based on HSI curves.
Report on the influence that sediment-flushing from dams exercises over ayu (Plecoglossus altivelis altivelis) in the Kurobe River
Katsuhiko NAGUMO*CKazuya SAWAHARA**CHideyuki KITAMURA*CIsao MORI***Cand Takehiro SHIRAO***
*:Kurobe River Office Ministry of Land, Infrastructure and Transport
**:Toyama River and National Highway Construction Office Ministry of Land, Infrastructure and Transport
***:ECOH Corporation River Environment Design Division
Implementation of coordinated sediment-flushing of Unazuki Dam(completed in 2001 by the Ministry of Land,Infrastructure and Transport) and Dashidaira Dam(completed in 1985 by the Kansai Electric Power Co.,Inc.) in the Kurobe River has been a practice since 2001. This study has been conducted for the purpose of recognizing the impact that the sediment-flushing or floods make over the habitat and food environment of ayu (Plecoglossus altivelis altivelis) living in the river. The results of the research held after a flood, which came up to the implementation standard of sediment-flushing, revealed the decline of the catch and the exfoliation of algae, food for them, adhered to rocks and stones in water, the latter with the decrease of their condition factor, although it was not clear whether the phenomenon was caused by the sediment-flushing or the flood. Besides, one month after the survey, a gain in the weight of the contents of the digestive tract and the increase of their condition factor were observed. In addition, it was perceived that ayu flown into the sea after the flood, from an otolith examination, that mainly natural ascending population among them swim back upriver again.
Observation and Numerical Simulation on Water Quality Change of Hori River in Winter Season
Makoto TAKEDA*, Azusa HIOKI**, Satoshi TOYAMA***, Naoki MATSUO*
*:Dept. of Civil Engineering, Chubu University, JAPAN
**:Civil Engineering Division, Graduate School of Engineering, Gifu University,JAPAN
***:Computron Co., Ltd.,JAPAN
[Makoto TAKEDA] firstname.lastname@example.org
[Naoki MATSUO] email@example.com
The aim of this study is to evaluate the features of distribution of water quality, relationship of water qualities and characteristics of water quality change in winter season in Hori River by observation and numerical simulation. From this study, it is found that the DO concentration increases due to inflow water from Nakagawa Canal at the area near the Matsushige Bridge. From the observation, it is found that the DO concentration of Hori River is increased in winter season in 2005. It is also found that water quality in the Hori River is improved due to inflow water from the Nakagawa Canal. To evaluate this phenomenon, the numerical simulation model is developed. The validity of this analysis model is shown by comparison of observed data with analysis data. Moreover, the analysis results with various analysis conditions show that the water quality in Hori River is affected by inflow water from Nakagawa Canal. Especially, the high DO concentration of Nakagawa Canal is most important for increasing DO concentration in Hori River.
Estimation of the effects of Al hydrolysis products on river ecosystems using attached algae as bioindicator
SASAKI Atsushi*, TATE Noriaki**, ITO Ayumi***, AIZAWA Jiro****, UMITA Teruyuki****
*:Technical Division of Instrumental Analysis, Faculty of Engineering, Yamagata University, Japan
**:Dept. of Civil and Environmental Engineering, Graduate School of Engineering, Iwate University, Japan
***:Dept. of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University, Japan
****:Dept. of Civil and Environmental Engineering, Iwate University, Japan
[ITO Ayumi] firstname.lastname@example.org
The influence of Al hydrolysis products on the survival of attached algae in an acidic river was estimated by the bioassay using the diatoms (Nitschia palea and Achnanthes minutissima) as test algal materials. The bioassay was conducted under the pH conditions of 4.5 and 6.0 by culturing the test algal materials in two types of hydrolyzed Al solutions: one solution contained dissolved polymeric Al fraction (Al-b) with a high concentration and the other with a low concentration.
In the bioassay using Nitschia palea under the both pH conditions, the chlorophyll a concentrations decreased rapidly in the solutions containing high concentrations of a polymeric Al fraction compared with those containing low concentrations. In the bioassays using Achnanthes minutissima under the pH condition of 6.0, the chlorophyll a concentrations decreased more rapidly in the solutions containing high concentrations of a polymeric Al fraction than in the other solutions.
From the multi-regression analysis, it was confirmed that Al-b fraction inhibited distinctly the inhabitation of Nitschia palea under the pH conditions of 4.5 and 6.0 and Achnanthes minutissima under the pH condition of 6.0.
Relative Evaluation of Reclaimed Wastewater in Urban Area in Comparison with the Distribution of River Water Quality
Arata HARADA*, Norihide NAKADA*, Naoyuki YAMASHITA**, Nobuyuki SATO***, Mitsuaki ITO***, Yutaka SUZUKI*, Hiroaki TANAKA**, Hiroaki FURUMAI****
*: Water Environment Research Group, Public Works Research Institute
**: Research Center for Environmental Quality Management, Kyoto University
***: METOCEAN Environment Inc.
****: Research Center for Water Environment Technology, the University of Tokyo
[Arata HARADA] email@example.com
Recently, it is expected to utilize reclaimed wastewater water for a new water source in urban areas. However, adequate assessment about the relative risk and the acceptance of the reclaimed wastewater should be conducted from the viewpoint of water usage. In this study, we relatively evaluated the quality of reclaimed wastewater in comparison with a gcriterionh based on nationwide distribution of river water quality.
At first, we selected 36 rivers with various sizes of the river basin area from all over Japan. Then, after we analyzed and collected various chemical and biological items of water quality of each river, those in the selected rivers were manipulated in the form of non-exceeding probability. The probability results were similar in key water quality items to those of all the major rivers in Japan, which suggest that the distributions of water quality items based on the selected rivers can represent all the major rivers in Japan.
Next, we compared the water qualities of secondary effluent and reclaimed wastewaters treated with sand filter, ozone and soil aquifer, with the distribution of water quality of the selected rivers. For an example, estrogen-like activity of secondary effluent equivalent to over the 90th percentile of the rivers decreased to about the 40th percentile of the rivers that is medium quality level through the ozonization process or the soil aquifer treatment. The other water quality items except nitrogens were also greatly improved by the above processes to the same way.
Stable Isotope Analysis for Understanding Nitrogen Behavior in Soil Receiving Irrigation of Reclaimed Wastewater
Takayuki SHIGEMATSU*, W.K.C.N.DAYANTHI*, Naoyuki YAMASHITA* , Hiroaki TANAKA*, Kouji TSUSHIMA**,Kunihiko AMANO**,Tadashi YAMASHITA***
*:Research Center for Environmental Quality Management, Kyoto University
**:Public Works Research Institute
***:Cabinet Land Improvement General Office, Okinawa General Bureau
Reclaimed wastewater will be introduced to alternative irrigation in the southern part of Okinawa Island. One of the concerns is that nitrogen found in reclaimed wastewater may cause adverse effects on the environment such as soil and ground water. We set up laboratory soil column experiments with two irrigation types (continuous & intermittent) in order to examine the behavior of nitrogenous compounds below the ground. As a result, NH4+ concentration in pore water and effluent of the both columns decreased because of the adsorption to soil and nitrification. NO3- concentration increased in the top and medium layers of the columns under both conditions. Then it decreased in pore water of the lower layers and the effluent of the column under the continuous condition. Nitrogen stable isotope ratio(Â15N) measurement was conducted to understand the behavior of nitrogen in the column. As a result, Â15N values of the effluent under the continuous condition tended to increase due to time and reached to a large value. These results suggest that the decrease in NO3- concentration in the lower column under the continuous condition was caused by denitrification, which demonstrates that stable isotope analysis is effective for understanding the behavior of nitrogen in the soil.
A method for designing monitoring well networks to detect LNAPL plume
*INOUE Kazuya, ** MASAKI Ippei, * TANAKA Tsutomu
*Faculty of Agriculture, Kobe University, JAPAN
** Graduate School of Science and Technology, Kobe University, JAPAN
Monitoring networks are designed based on a developed methodology linked contaminant transport simulations from LNAPL source and optimization models. Advection and dispersion simulation generates LNAPL plume realizations while the use of Latin hypercube sampling accounts for uncertainty in transport parameters and in contaminant source characteristics. Genetic algorithm provides a prescribed number of wells in order to maximize a number of detectable LNAPL plumes with a concentration above a specified limit and incorporates temporal moment into objective function to reduce the weight regarding plume detection at a monitoring point where lateral dispersion contributes to the increase of detection probability. Several examples of the method in a three-dimensional hypothetical domain are presented to show the effect of probability density function on a monitoring network, suggesting that source characterization has a substantial effect on allocation of wells relative to transport parameters. Additionally, the results reveal that a little difference of boundary conditions between second-type and third-type is observed while the detectable limit is an important factor in monitoring network design.
A Study on Characteristics of Settling Matters in the Mud Flat of the Ariake Sea
Hiroyuki YAMANISHI*, Kenichi HIMURA**, Yasuyuki KOGA**, Aoi MAEDA***, Kyoko OHISHI****, Takahisa TOKUNAGA* and Hiroyuki ARAKI*
*:Institute of Lowland Technology, Saga University
**:Dept. of Civil Engineering, Graduate School of Engineering, Saga University
***:Branch of Matsuyama, Anabuki Construction Ltd.
****:Dept. of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University
[YAMANISHI Hiroyuki] firstname.lastname@example.org
In this research, behaviors of suspended matters on the mud flat were investigated by using the sediment-traps and observation towers. Results obtained from the analysis of the amounts of sedimentation and nutrients reveal the characteristics of settling matters in the mud flat. The settling flux observed in the sediment-tarps almost coincided with the net settling flux obtained from a theoretical calculation, because the influence of erosion did not seem to appear. Therefore, the constituent difference of settling matters in the sediment- traps did not appeared. The amount of sedimentation to the mud flat was also estimated based upon the settling flux measured in this study. It is shown that the fine cohesive sediment transport in the area was demonstrated through examining the observed data in three towers.
Study on Novel Oxygen Supply Process by Contacting Water Film with Air.
TANI Kousuke, IMAI Tsuyoshi , Hua Zhu , TERAOKA Satoshi, UKITA Masao, SEKINE Masahiko and HIGUCHI Takaya
Graduate School of Science and Engineering, Yamaguchi University, JAPAN
It is said that the power consumption of aeration process in the wastewater treatment plant where the activated sludge method is applied ,approximately occupies for 50% of the power consumed in the whole wastewater treatment plant. For this reason, raising the efficiency of aeration has an important meaning. In this study, surface transfer is replaced by contacting liquid film with air. The experimental results from single-pass aeration mode showed that oxygen transfer efficiency in this novel aeration apparatus is improved by 40 % under a condition of the labscale experiment in comparison with the conventional aeration apparatus.
Studies on growth control of toxic cyanobacteria by use of the dead leaves of deciduous trees
NOBUMASA Kitamura*,TOKIO Nagakawa*,YUKIHITO Yoshida**, HITOMI Matsushima**, YASUO Asada***
*:Graduate School of Science and TechnologyC Nihon University
**:Dept. of Civil EngineeringC College of Sci. & Tech.C Nihon University
***:Dept. of General EducationC College of Sci. & Tech.C Nihon University
Because of the acute toxicity of microcystin that is produced by toxic cyanobacteria in hyper-eutrophicated lakes and reservoirsC it is necessary in term of water resource and water quality preservation not only to remove the cyanobacteria by any meansC but also to rationally and effectively control its excess growth. From the viewpoint of the natural environmental restorationC the authors have focused attention to the function of the water-extracts from the dead-leaves of deciduous trees that may contain polyphenolC and have examined on the effects over the growth control of toxic cyanobacteria like Microcystis aeruginosa (NIES 102). The water-extracts from the dead-leaves was simply prepared by immersing each kind of various dead-leaves of the different deciduous trees into DI water and was put into a culture medium of Microcystis aeruginosa to observe the cell number changes with timeC resulting in obtaining that the addition of the water-extracts showed an effective growth control to Microcystis aeruginosa. The condensed tannin of the water-extracts and its loading intensity would be the possible factors affecting the growth control for Microcystis aeruginosa.
Behaviors of Physiologically Active Bacteria in Water Environment
Keisuke SAWAYA*, Nakaichiro KANEKO**, Junichi YAGUCHI**
*:Advanced Course of Enviromental and Civil Engineering ,Hachinohe National College of Technology
**:Department of Enviromental and Civil Engineering ,Hachinohe National College of Technology
Bacteria in the water environment were enumerated by plate counting and fluorescent staining methods. 4f,6-diamidino-2-phenylindole(DAPI) was used to determine total bacterial numbers, and 5-cyano-2,3-ditolyl tetrazolium chloride(CTC) was chosen for direct fluorescent microscopic detection of respiring bacteria. BacLightTM kit was used to assess bacterial membrane integnity. Bacteria with growth potential were enumerated using micro-colony technique and direct viable counting(DVC). The total bacterial number in river was 8x106?5x109cells/mL, and colony forming units on R2A media were 1x104?4x105cells/mL. In the case of wastewater treatment plant, 1?10% of total bacterial cells could form colonies. Physiologically active bacteria in river and wastewater treatment plant determined by fluorescent stainig were much higher than those obtained by plate counting.
Evaluation of baisin aquatic biodiversity using HSI model
Hiroshi HAMAMOTO*, So Kazama*, Masaki SAWAMOTO**
*:Gratuate School of Environmental Studies, Tohoku University
**:Gratuate School of Engineering, Tohoku University
[Hiroshi HAMAMOTO] email@example.com
In the Natori River basin, we evaluated aquatic habitat with HSI model. Dynamic data in the modeling are prepared for distributed runoff model and water and heat balance model. To estimate suitable HSI, statistic data and field data are combined after testing some combinations. The best way is that temperature and the other SIs should be calculated by statistic and field survey data, respectively. Biodiversity is obtained from the combination of HSIs for each speacies. As the results, biodiversity is higher around the foot of mountains and is correlated with distribution of dragonflys. This results say that dragonfly habitat is usefule for understanding of basin environment.
Estimation of Suspended Substance Amount Based on Investigation Study of Pipeline Flushing for Water Distribution Network
*:Takaharu KUNIZANE,*:Toyono INAKAZU,*:Akira KOIZUMI ,**:Hiroki ARIYOSHI,**: Masahiro SHIMOMURA
*:Graduate School of Urban Environmental Sciences,Tokyo Metropolitan University
**:Saitama Municipal Waterworks Bureau
In Japan, most water supply facilities were constructed during the 1960fs to 1970fs, and they are becoming old. And then there are some problems occurred, such as deteriorated water quality due to contamination with suspended substance in aging pipes in late years. So Flushing distribution network is performed by water utilities to maintain the water quality in pipeline. But aging pipes are increasing year by year. Therefore more effective maintenance and management plans are expected.
This paper proposes an expression to study occurrence of suspended substance in distribution network. This expression model is based on an investigation of flushing work for pipeline carried out by a water utility, and it is a method to measure quantity of iron rust occurrence in distribution network by relation between length of aging pipe and average flow velocity in some objective area.
By using this model , it will be able to make a plan for effective work on pipeline flushing and estimate outbreak risk of deteriorated water quality (Red water etc.) by the scenario analysis based on future water demand forecasting.
An Empirical Model for Predicting Dewatering Efficiencies of Waterworks Sludge
Tomo OIKAWA*,**, Hiroyoshi KITAZAWA*,***, Chikafusa SATO*,****, Akira KOIZUMI*
*:Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University
**:Water Quality Management Center, Bureau of Waterworks Tokyo Metropolitan Government
***:Purification Division, Bureau of Waterworks Tokyo Metropolitan Government
****:Training and Technical Development Center, Bureau of Waterworks Tokyo Metropolitan Government
[Tomo OIKAWA] firstname.lastname@example.org
An empirical model for a dewatering efficiency of waterworks sludge was developed. In waterworks sludge treatment, it was difficult to predict the dewatering efficiency from cake filtration theory. Therefore, at the time of a sludge treatment plant construction, expensive pilot tests were needed to determine sludge pretreatment methods and schemes, and often they were not feasible.
In this study, the effect of pre-treatment (mechanical thickening and heating) on dewatering efficiency was investigated by pilot filter-press. By comparison between experimental results and cake filtration theory, it was found that filter resistance could not be neglected. As a result, a model for a dewatering efficiency (i.e. a filtration rate), which included the filter resistance, was developed. According to the model, the filtration rate is described as a function of the solid concentration, the cake specific resistance and filtrate viscosity. The filtration rates calculated from the model were in a good agreement with the experimental results. Therefore, the model can serve to predict the effect of sludge pretreatment processes.
Fractionation and characterization of hydrophilic substances from Microcystis aeruginosa inducing coagulation
Tomoko TAKAARA*, Daisuke SANO*, Takeshi SUTO*, Hiroshi KONNO** and Tatsuo OMURA*
*:Dpt. of Civil Engineering, Graduate School of Engineering, Tohoku University
**:Dpt. of Civil Engineering, Graduate School of Engineering, Tohoku Institute of Technology
Mass propagation of algae in drinking water source affects the coagulation process in water treatment systems. Algogenic organic matter (AOM) interacts with coagulants or suspended substances, and brings about several disorders in water treatment processes, but the inhibitory mechanism on the coagulation by AOM has remained to be elucidated. In this study, hydrophilic substances extracted from Microcystis aeruginosa (M. aeruginosa) were found to involve potent inhibitory substances for coagulation with polyaluminum chloride. Those inhibitory substances were possible to be precipitated by ethanol. The fractionation of the precipitated AOMs with ultrafiltration and anion exchange enable us to confirm that the inhibitory substances have a net negative charge under the pH value of 8.0, and the molecular weights of those are larger than 10kDa. Lipopolysaccharide and RNA could be the possible inhibitory substances involved in the hydrophilic substances from M. aeruginosa, and how this algal organic matter induces the coagulation inhibition would be elucidated in the further study.
Control of membrane fouling by pre-coating with coagulant coated diatomite
IKEGAMI Takeshi*, OKUDA Tetsuji**, NISHIJIMA Wataru**, OKADA Mitsumasa***, KADOKAWA Naruaki**** , MOTOYAMA Nobuyuki****
*:Dept. of Engineering, Hiroshima University, Japan
**:Environmental Research and Management Center, Hiroshima University, Japan
***:DirectorEVice President, Hiroshima University, Japan
****:Fuji Electric Systems Co., Ltd., Japan
[IKEGAMI Takeshi] email@example.com
[OKUDA Tetsuji] firstname.lastname@example.org
In order to control membrane fouling, the inner surface of a microfiltration membrane was pre-coated with diatomite having particle diameter of about 14Êm, with or without polyaluminum chloride iPACj coating. Reservoir and stream water samples containing suspended particles with sizes of about 0.4?0.8Êm were filtered with the pre-coated membranes. Fouling could not be controlled with the membrane pre-coated with only diatomite, but was significantly reduced with the membrane further coated with PAC. The additional PAC coating rendered the negatively-charged diatomite surface positive, from -37 mV to +30 mV, thereby complementing the negatively-charged suspended particles in the sample water, thus reducing membrane fouling.
PERFORMANCE EVALUATION OF OZONE/CHLORINE SEQUENTIAL TREATMENT BY CHROMOSOMAL ABERRATION TEST
Shinya ECHIGO, Sadahiko ITOH, and Tomoki NATSUI
Department of Urban Management Kyoto University, Department of Urban Management Kyoto University, Ministry of Health, Labour and Welfare
Chromosomal aberration test was performed to evaluate the toxicity of the water treated by ozone/chlorine sequential treatment. The bias caused by sample concentration processes was evaluated for fair comparison of the results of chromosomal aberration test based on the recovery of the activity inducing chromosomal aberrations. It was found that the bias in favor of the ozone/chlorine sequential treatment does not exist. This result confirms the effectiveness of ozonation to reduce the risk of reaction byproducts in past evaluations.
Practical Purification of Coagulation Active Component Extracted from Moringa oleifera seeds by Salt Solution and Its Performance
OKUDA Tetsuji*, NISHIJIMA Wataru*, and OKADA Mitumasa**
*:Environmental Research Management Center, Hiroshima University, JAPAN
**:DirectorEVice President, Hiroshima University, JAPAN
[OKUDA tetsuji] email@example.com
[NISHIJIMA Wataru] firstname.lastname@example.org
The coagulation active component in the solution (MOC-SC) extracted from Moringa oleifera seeds by salt solution could coagulate not only turbid materials but also humic substances. The purified solution from MOC-SC with dialysis, defatting and redissolution with 0.3 M NaCl solution was determined as practical coagulant which can work at nutral pH. The coagulation activity of the practical purified solution was demonstrated using real reservoir and river water, and it could decrease turbidity and E254 with over 95% and about 40%, respectively.
Perfluorinated substances in tap water of Japan and several countries and their relationship to surface water contamination
Nguyen Pham Hong LIEN*, Shigeo FUJII*, Shuhei TANAKA*, Munehiro NOZOE*, Wanpen WIROJANAGUD**, Ann ANTON*** and Gunilla LINDSTROM****
*Research Center for Enviromental Quality Management, Kyoto University.
**Research Center for Environmental and Hazardous Substance Management, Khon Kaen Universisty.
***Biotechnology Research Institute, School of Science and Technology, Universiti Malaysia Sabah.
****MTM Research Center, Department of Natural Sciences, Orebro University.
Recently, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), which are concerned as a new class of persistent organic pollutants, have been found to be widely distributed in many living organisms including human. We measured concentrations of PFOS and PFOA in 38 tap water samples collected from several areas in Japan, Thailand, Malaysia, Sweden, Vietnam, China and Canada; and conducted systematic surveys of PFOS and PFOA at surrounding surface water sites. A solid phase extraction coupled with liquid chromatography/mass spectrometry (LC-MS) was used for analysis. Main conclusions were as follows: (1) Most of collected tap water samples were contaminated with PFOS and PFOA with the concentrations ranged from the limit of quantification levels to 13 ng/L for PFOS and 109 ng/L for PFOA. (2) The level of tap water concentrations was generally related to the level of surrounding surface water concentrations whether the source of tap water was the surface water or not. (3) In Japan, tap water PFOA concentrations were relatively high in Biwako-Yodo River area (Otsu, Kyoto, Osaka), mostly due to its contamination of Lake Biwa and Yodo River.
Aerobic and anaerobic biotransformation of 17 beta-estradiol in sediment cores
LI Fusheng*, DESMIARTI Reni**, YUASA Akira***, SUZUKI Yutaka****
*: Department of Civil Engineering, Gifu University, JAPAN
**: Graduate School of Engineering, Gifu University, JAPAN
***: River Basin Research Center, Gifu University, JAPAN
****: Water Environment Research Group, Public Works Research Institute, Japan
[LI Fusheng] email@example.com
Four sediment cores consisted of 30cm of undisturbed sediment and 60 cm of overlying water collected from two sites within a natural reservoir were designed and the behavior of 17 beta-estradiol (E2) spiked into the overlying water of the sediment cores was investigated. Besides, with the addition of glucose, the likely effect of easily degradable organic substrates upon the behavior of E2 and its biotransformation intermediate of estrone (E1) was also assessed. The results showed that the spiked E2 (at 16.5 microgram per liter) disappeared faster in aerobic sediment cores than in anaerobic ones, and under both aerobic and anaerobic conditions, E1 was formed as the biotransformation by-product of E2 and then disappeared from the water phase in a pace considerably slower than E2. The half-lives of E2 without and with the coexistence of glucose (added at three different concentration levels) varied in 0.4~7.5 hours for runs of the aerobic cores, while those for runs of the anaerobic cores in 2.7~15.1 hours. The removal of glucose quantified using the index of TOC was also found faster in aerobic sediment cores than in anaerobic ones.
Effect of sediment grain-size on removal of hazardous organics by indirect thermal desorption.
Ryo KOIZUMI*, Shogo TANIGUCHI**, Hiroaki OZAKI***
*:Dept. of civil Engineering, Osaka Sangyo University graduate school
**:New Industrial Research and Development Center, Osaka Sangyo Univ
***:Dept. of civil Engineering, Osaka Sangyo University
[Hiroaki OZAKI] firstname.lastname@example.org
Sediment pollution by hazardous organics like dioxins and Polychlorinated Biphenyls (PCBs) has become a problem these days. Since factors like specific surface area and organic carbon content of sediments influence adsorption/desorption characteristics of hazardous organics, grain-size may affect removals of the organics in contaminated sediments. This paper aimed to investigate grain-size effect on removals of dioxins and PCBs by indirect thermal desorption method. Sieved (75-2000Êm, 20-75Êm and >20Êm fractions) and not sieved contaminated sediment samples were heated in quartz tubes up to 400. Concentrations of organics were measured in the remaining sediment samples and off-gas colleted during the experiments. Grain-size did have influence on dioxin removals and the removal efficiency increased with smaller grain-size fractions. About 95 removal efficiency was observed in less than 75Êm fractions. However, almost the same removals (>99%) were observed with all the sediment fractions in case of PCBs. Therefore sedimentation can be an effective step before remediation of dioxin-contaminated sediments by indirect thermal desorption technique.
DISTRIBUTION OF PCDDs/PCDFs IN SEDIMENTS FROM THE PONG RIVER, KHON KAEN, THAILAND
Alissara REUNGSANG*, Satoshi TAKIZAWA**, Wanpen WIROJANAGUD*
*: Research Centre for Environmental and Hazardous Substance Management, Khon Kaen University.
**: Department of Urban Engineering, The University of Tokyo.
[Alissara REUNGSANG] email@example.com [Satoshi TAKIZAWA] firstname.lastname@example.org [Wanpen WIROJANAGUD] email@example.com
Despite increasing concern over dioxins in water environments near pulp and paper mills built in Asian developing countries, little information was made available due to lack of technical and financial resources for HRGC/HRMS analysis. This study was conducted to determine a distribution of PCDDs/PCDFs in sediments from the Pong River using an immunoassay kit. The highest concentration of total PCDDs/PCDFs (130 pg-TEQ/g) was found in a sediment sample collected from the discharge point and the second highest (99 pg-TEQ/g) was found at the land treatment area. Principal congeners of PCDDs/PCDFs analyzed by HRGC/HRMS were 2, 3, 7, 8-TCDD and 2, 3, 7, 8-TCDF in a sediment sample collected from the holding pond of a pulp and paper mill, which indicated PCDDs/PCDFs formation from the bleaching process. Land treatment and the holding ponds of the pulp and paper mill showed effectiveness in reduction of PCDDs/PCDFs in the sediments of the Pong River. The levels of PCDDs/PCDFs detected in all samples was lower than the Japanese Environmental Quality Standard of 150 pg-TEQ/g sediment, but the results suggested that further efforts are necessary to reduce the levels of PCDDs/PCDFs in the Pong River.
Behaviour and fluxes of polycyclic aromatic hydrocarbons in atmospheric deposition
Dept. of Environmental Systems Engineering, Toyama Prefectural University, JAPAN
A detailed investigation was carried out from August 2001 to January 2003 in the suburban region in the central part of Toyama Prefecture, Japan in order to elucidate concentration characteristics of polycyclic aromatic hydrocarbons (PAHs) in precipitation and dry fallout, the mutagenicity of precipitation and the fluxes of PAHs by precipitation and dry fallout. The following results were obtained: (1) The concentration of PAHs in precipitation became high in the winter and low in the summer. (2) Multi-regression analysis between PAH concentration and meteorological conditions suggested that cross-boundary pollution and dilution by precipitation might affect the fluctuations in PAH concentration. (3) In the case of PAHs with low molecular weight, soluble-phase PAHs exsisted to some extent because of high water solubility. The partition to particulate phase was ten to ten thousand times larger than that in the equilibrium state. (4) The mutagenicity of precipitation was strong in the winter and weak in the summer. It was suggested that nitro-PAHs might be the main cause of the mutagenicity. (5) The annual deposition load of PAHs by precipitation was 672 g km-2y-1 whereas the annual load by dry fallout was 25.6% of that by precipitation.
A Study on the Vehicle CO2 Reduction by Municipalities in Consideration of the Character of the Area
Makoto Okazaki*CYoshihiko Hosoi**
*:Tottori University of Environmental Studies
**:Tottori University, Faculty of Engineering
The increase in the CO2 emission from a transportation sector is remarkable in our country, and it is desired to promote the countermeasure by municipalities of the whole countries based on its character of the CO2 emission. However, it is not easy to grasp the structure of the emission in the municipalities up to the present. Using OD investigation data of the road traffic census, this study shoed the estimation method of CO2 emission from vehicle by the type of vehicle, by the use purpose and so on. The estimated emissions were compared with other estimations and the validity was examined. Moreover, the various analytic examples which ware useful for the policy-making ware shown, and effect of countermeasure ware estimated.
Observation and characterization of the surface heat budget on a rooftop planted with Sedum
HIRANO Yujiro*, ICHINOSE Toshiaki**
*:Department of Electronic Engineering, Gunma University, JAPAN
**:National Institute for Environmental Studies, JAPAN
[HIRANO Yujiro] *************
Rooftop greening is considered to mitigate the effects of the urban "heat island" phenomenon and is becoming increasingly popular in Japan owing to its promotion by local governments in recent years. To evaluate the evaporative cooling effects of rooftop vegetation, we measured the surface heat budget and several related parameters on the rooftop of a three-story office building planted with Sedum. The measurements were made on two clear-sky days in September. The results indicate that the albedo and the emissivity of Sedum are 0.153 and 0.995, respectively. Under the meteorological conditions at the time of measurement, the evaporation efficiency after irrigation was around 0.21, and the latent heat flux was around 300-400 W/m2 at mid-day.