(Environmental Engineering Research)
Vol.45 (2008)


Behaviors of arsenic leaching factors imaging the Bangladesh aquifers
TAKAHASHI Naoki*, SATO Yoshio**, ISHIBASHI Yoshinobu**, HAN Youn-Hee**, RAHMAN M.T.***, MANO Akira***
*:Miyagi Prefectural Authority for Living Environment, JAPAN **:Graduate School of Engineering, Tohoku gakuin University, JAPAN ***:Graduate School of Engineering, Tohoku University, JAPAN
[ISHIBASHI Yoshinobu] yishi@tjcc.tohoku-gakuin.ac.jp
The influences of various chemicals causing anaerobic arsenic leaching from sediment towards groundwater in the alluvial aquifers in Bangladesh were investigated. Consequently, significant influence on arsenic leaching was observed by using phosphoric acid as a leaching agent. Leaching was further promoted when organic phosphate particularly triphenylphosphine, concentration 630 times against control, was utilized. Conversely, remarkable arsenic leaching was also noticed in an alkaline condition by using ammonia. Besides, functions of microorganisms were also examined. Finally, estimation of sorption reaction coefficients was performed to be used with the fundamental equations illustrating arsenic transport in the reducing aquifers.

Study on Runoff Characteristic and Pollutant Loading of Particulate Matter discharged from small Agricultural area
Hyungjun LEE, Takanori MASUDA, Yoshihiko HOSOI
The Graduate school of Engineering, Tottori University
The purpose of this study is to characterize and quantify the SS (Suspended Solids), PN (Particulate Nitrogen) and PP (Particulate Phosphorus) discharged from agricultural area which located in Lake Koyama watershed of Tottori city. According to the survey carried out on fine days, there is much difference of pollutants discharge among the agricultural events. SS, PN and PP concentration showed a sharp peak in puddling and rice-planting periods. SS and PP concentration increased in the first half of mid-summer drainage period. PN showed a peak in harvest period. About the pollutants net loading, many pollutants of SS, T-P and PP are discharged in puddling and rice-planting periods, while flow rate is small. On the other hand, T-N and PN loading sometimes showed negative net loading. Rainy season loading was estimated by tank model and L-Q equation. From the fine day and rainy season results, unit loadings of SS, T-N, PN, T-P and PP were estimated at 785,16.9,3.9,6.7,3.3 kg/ha/yr.

Understanding of Runoff-Mechanisms of Nutrient Pollutant from Domestic Wastewater and Livestock Wastewater using Tracers
*Water Quality Research Division, Public Works Research Institute, JAPAN
[OKAYASU Yuji] okayasu@pwri.go.jp
[SUZUKI Yutaka] ysuzuki@pwri.go.jp
In order to understand runoff-mechanisms of nutrient pollutant from watershed to receiving water body, concentrations of tracers (i.e., sodium ion, potassium ion) and nutrients in domestic wastewater and occurrence of their runoff in dry weather were studied in two watersheds. In a watershed, where mainly domestic wastewater is discharged, results show that domestic wastewater is diluted by base flow. In the other watershed, where considerable amount of livestock wastewater is suspected to be released, it was possible to estimate existence of point source except for domestic wastewater by analyzing ratio between tracers and ratios of nutrient to the tracer.

Evaluation of dynamics of PPCPs at Yodo River System
Seiya HANAMOTO1, Hiroki SUGISHITA1, Naoyuki YAMASHITA1, Hiroaki TANAKA1, Isao HOWA2 and Chie KONISHI2
1:Research Center for Environmental Quality Management, Kyoto University, JAPAN
2:Murata Keisokuki Service CO., Ltd., JAPAN
[Seiya HANAMOTO] hanamoto@biwa.eqc.kyoto-u.ac.jp
Degradation of PPCPs in the water environment was evaluated. On the assumption that the degradation is a first-order reaction, the reaction constants were calculated by comparing the mass load of upstream and
downstream and the time of flow at Yodo River System. Batch experiments were also conducted and the reaction constants were determined and compared with those of the river surveys. These were greatly different for ketoprofen, azithromycin, diclofenac and levofloxacin, suggesting the other mechanisms of decrease in the concentrations such as photodegradation or adsorption to the sediments. In the river surveys, biodegradability was found much different depend on the sites.

Evaluation of suitable hydraulic conditions for living environment of fishes with horizontal 2-D numerical simulation and PHABSIM
NAGAYA Takayuki*, SHIRAISHI Yoshiki**, UKESE Asuka*, ONITSUKA Kouki***, HIGASHINO Makoto,****, TAKAMI Tohru****, HIGASHI Hitoshi*****, AKIYAMA Juichiro***
*CTI Engineering Co., Ltd.
**Public Works Research Institute
***Department of Civil Engineering, Kyushu Institute of Technology
****Department of Civil Engineering, Oita National College of Technology
*****Nobeoka Work Office, Ministry of Land, Infrastructure and Transport
[NAGAYA Takayuki] nagaya@ctie.co.jp
Before river improvement work, it is necessary to conduct the environmental assessment. However, the accuracy of the environmental assessment is not so high, because the preference curves of the flow depth, velocity and so on have been not clear. Recently, the preference curves of the flow depth, velocity and substrate concerning with Zacco platypus, Zacco temminckii, Tribolodon hakonensis and Rhinogobius flumineus are suggested by Komura. In this study, the living environment of those fishes in Gokasegawa River is predicted on the basis of preference curves suggested by Komura. Further, environmental characteristics were compared. As a result, the most suitable cross section was suggested.

Study on the Evaluation of the Bottom Shear Stress in Estuaries
SAKAMOTO Jun-ichi*, MATSUMOTO Haruhiko**, HADANO Kesayoshi***, AMANO Takuzo
*:Chuo Kaihatsu Corporation
**:Dept. of Human Society, Ube Frontier University, JAPAN
***:Dept. of Civil and Environmental Engineering, Yamaguchi University, JAPAN
****:Chuden Engineering Consultants Co., Ltd.
[SAKAMOTO Jun-ichi] sakamoto@ckcnet.co.jp
The formation of oxygen-poor water and the occurrence of hydrogen sulfide in estuary are caused by the sludge which contains a lot of organic substance. In order to examine measures against the water environment problems caused by the sludge, it is necessary to evaluate bottom shrear stress which considered to exert influence on the behavior of bottom material. In our study, the characteristics of time variation of salinity flux and ss flux calculated from results of field observation were considered. The bottom shear stress was evaluated by using the change of water level obtained by one-dimensional unsteady flow analysis and the density distribution obtained by field observation. As a result, it is expected that the bottom shear stress is governed by the slope of water surface and the horizontal density gradient when the tip of saline wedge passes.

Influence of flushing on the estuarine tidal flat ecosystem developed in the mouth of Ohtagawa flood way
Shinichi WATAYA1, Yoichi NAKANO2, Tsuyoshi IMAI1, Satoshi NAKAI3, Wataru NISHIJIMA4 and Mitsumasa OKADA3
1 Graduate School of Science and Engineering, Yamaguchi University
2 Department of Chemical and Biological Engineering, Ube National College of Technology
3 Graduate School of Engineering, Hiroshima University
4 Environmental Safety Center, Hiroshima University
The Ohtagawa flood way is connected with Ohtagawa river via Gion floodgate. Under the normal times, the discharge water volume for the Ohtagawa flood way is maintained to keep its structure and functions, such as biological productions, however flushing is carried out in the case of a heavy rain which may cause flooding of Ohtagawa river. The flushing inevitably disturbs the tidal flat ecosystem developed in the flood way. This research was carried out to investigate how the flushing disturbs the estuarine tidal flat ecosystem developed in the mouth of Ohta flood way. The flushing caused runoff of the tidal flat surface soil and/or macrobenthos, of which degrees were dependent on the water volume and the period of flushing. The measurement of the tidal flat surface level revealed that about 10 cm of the surface soil was run off by the flushing in 2006 with 5.57 m of water level measured at Yaguchi-daiichi observing station, while that with 8.81 m in 2005 vanished 50% of the macrobenthic population. After the flushing, the level of the tidal flat surface and macrobenthic population were finally recovered to the original conditions.

Effect of counter cation on growth inhibition of Brassica campestris induced by bromate
Yukiko KAWAMUKAI 1, Naoya SATTA 2, Takahiro TATEISHI 3
1:Graduate school of Agriculture, Iwate University
2:Dept.of Environmental Science, Iwate University
3:Dept.of Agro-bioscience, Iwate University
[Yukiko KAWAMUKAI] a3208008@iwate-u.ac.jp [Naoya SATTA] satta@iwate-u.ac.jp
In this research, the growth inhibition of Brassica campestris induced by bromate was examined to estimate effect of counter cation that is potassium(K) and sodium(Na). Consequently, KBr didn’t decrease length and dry weight of the edible part and just promoted growth increasingly. Growth inhibition of bromate was getting stronger with its concentration. At low concentration of 1mg/L KBrO3, Brassica campestris grew larger than the control on account of promotion effect of K. NaBrO3 caused impediment for growth at the same concentration. As good correlation was showed between growth inhibition induced by KBrO3 and bromate concentration, a linear regression equation was obtained. On the other hand, growth inhibition induced by NaBrO3 was fitted well for logarithmic equation.

Temporal change in fish fauna and environmental factors in a "Wand-channel" and "Wand-pool" which were constracted in the lower reach of the Edo-River
Kazuya NISHIDA*, Yumiko FURUSAWA**, Daisuke OKAZAKI*** and Yoshiteru KIMIZUKA****
*:United Graduate School of Agriculture, Tokyo University of Agri. and Tech.
**:Bureau of Environment, Tokyo Metropolitan Government
***:Faculty of Marine Science, Tokyo University of Marine science and Tech.
****:Choufu-shi, Tokyo
[Kazuya NISHIDA] 24kaz@cc.tuat.ac.jp
This study clarifies the fanction of the fish habitat and temporal change in fish fauna and environmental factors in a wand-channel and wand-pool which were constracted in the river of an urban area. The investigation was carried out from 1996 to 2008 in the lower reach of the Edo-River, its wand-channel and wand-pool.
As a result, Pseudorasbora parva, Oryzias latipes latipes and Gambusia affinis which were small and resident fish, inhabited in wand-channel and wand-pool. It was suggested that Cyprinus carpio and Carassius spp. spawned and the juvenile grew in there. Otherwise, the fanction deteriorated because of shallowing of water depth. However, it was suggested that the fanction restored by re-excavation. It was thought that demonstrating the factor that influence on inhabiting and spawning of the fish in wand-channel and wand-pool was hereafter issue.

Effect of emergence time and sediment on the growth of Zostera japonica
IKEGAMI Yusuke*, NOMURA Munehiro*, NAGAHAMA Yumi*, NAKANO Kazunori*, NISHIMURA Osamu*
*:Graduate School of Engineering, Tohoku University, JAPAN
[IKEGAMI Yusuke] ikegami@eco.civil.tohoku.ac.jp
[NOMURA Munehiro] nomu@eco.civil.tohoku.ac.jp
It is well known that a seagrass (Zostera japonica) has a function to let the benthic fauna of intertidal zone increase. To conserve and construct seagrass bed, it is important to clarify the relationship between growth conditions and environmental factors. However, it is difficult to understand the factors that affect the growth of Z. japonica from the results of a field survey. Therefore, a laboratory experiment was carried out to study the effect of environmental conditions such as emergence time and bottom sediment conditions on the growth of Z. japonica. The growth of Z. japonica was found to be good in the submergence condition, but it was not affected by the various sediment conditions. Thus, it was indicated that compared to sediment, emergence time is one of the most important environmental factors on the growth of Z. japonica.

The Influence of Demersal Habitat Structure Formed with Coastal Erosion on Macrobenthos and Demersal Fishes
Yumi NAGAHAMA*, Masateru OSHIMA**, Shuro YOSHIKAWA**, Kenji NEMOTO**, Osamu NISHIMURA* and Kenshi KIMURA**
* : Dept. of Engineering, Tohoku University
** : Dept. of Oceanography, Tokai University
[Kenshi KIMURA] kenshi@scc.u-tokai.ac.jp
[Yumi NAGAHAMA] nagahama@eco.civil.tohoku.ac.jp
We investigated the influence of coastal erosion on macrobenthos and demersal fishes in Miho coast, Japan. The coastal erosion in this area has been observed since 1983. In this study, it was shown that strong sediment flow on the sea floor was formed with long-term coastal erosion. Furhermore, it was suggested the generation of consecutive sediment flow brought movement of bottom of the sea soil in 25m water depth where the change of geographical features was not observed, and the specific demersal environment was difficult to form particulate organic matters. It is not only few food of macrobenthos that available, but also the fragile of habitats at the sea bottom, a place of primary succession, was occured. As a result, macrobenthic fauna was poorly build-up. In addition to, it was suggested that The richness of demersal fishes as macrobenthic feeder was decreased due to the decay of food resource that influences the initial growth and the reproduction of demersal fishes.

Development of a bivalve predation detecting procedure by eagle ray (Aetobatus flagellum) and other living organisms
HAGIHARA Junko*, SEKINE Masahiko*, OZOE Sayumi**, FUJII Akihiko* and WATANABE Moriyoshi***
*Graduate schoo, Science and Engineering,Graduate school, Yamaguchi University, JAPAN
**MIKUNIYA Corporation
***Akashi National College of Technology
[HAGIHARA Junko] k035vn@yamaguchi-u.ac.jp
The purpose of this research is to develop a bivalve predation detecting procedure. Clam predators like eagle ray (Aetobatus flagellum) crash clam shell to eat it. Firstly, we reveal the fact that eagle ray creates shot sounds when it eats short-necked clams through a sea water tank experiment. Secondly we make computer programs to count the pulse number included in a shot. The sounds created by the ray tend to include several pulses in a shot, whereas the sounds created by the crab tend to include only one or two pulses. A shot including more than three pulses can be the proof of the predation of the ray with 48% accuracy. This technique can be utilized for a ray migration monitoring system and/or a trigger device for a predation prevention system such as electric shocker.

The Mechanism of the Water-bloom Production in Urushizawa Dam Reservoir
Shuhei MASUDA1, Munehiro NOMURA1, Fumiyoshi TSUBONE2, Nobuo CHIBA1, Naoshi FUJIMOTO3, Kazunori NAKANO1 and Osamu NISHIMURA1
1Graduate school of Engineering, Tohoku University
2Pre-Graduate school of Engineering, Tohoku University
3Graduate school of Agriculture, Tokyo University
[MASUDA Shuhei] masuda@eco.civil.tohoku.ac.jp
[NISHIMURA Osamu] osamura@eco.civil.tohoku.ac.jp
Both of the field and the literature survey have been carried out to investigate the mechanism of the water-bloom production in Urushizawa dam reservoir. From the literature examination, the average value of the tempreture of the surface water was 22.3℃ in the year in which the water-bloom was generated, 17.4℃ in the year in which that was not. The cyanobacteria occupied larger than the greenalgae and the diatom when the tempreture of the surface water, TN, TP and TN/TP ratio was relatively high. This tendency was same in both of the field and the literature survey. It was indicated that the production of the cyanobacteria was derived by the vanish of PO4-P in the surface water. It was suggested that the vanish of PO4-P in the surface water was derived by the production of diatoms in spring, the discharge of diatoms to the outside of resouvoir and sedimentation. The increase of inflow due to the flash of the river promoted the production of the green algae, because of the disturbance of the aquatic environments in the dam reservoir and the supply of the phosphrus.

Evaluation of the estimation accuracy of high chlorophyll-a concentration in brackish lake using spectral reflectance data
*:Department of Environmental Engineering, Hiroshima University, JAPAN
**:National institute for Environmental Studies, JAPAN
[SAKUNO Yuji] sakuno@hiroshima-u.ac.jp
[MATSUNAGA Tsuneo] matsunag@nies.go.jp
The objective of this study is to evaluate the estimation accuracy of high chlorophyll-a concentaration (Chl.a) in the brackish lake (The test site is Lake Shinji) using the spectral reflectance data. As a result, the Chl.a estimation accuracy of "Lake Shinji Model" proposed by authors in the past was estimated to be 5.9 g/l (RMSE). When the high Chl.a estimation model proposed in the world was applied to Lake Shinji, the correlation of the reflectance ratio of "700 nm and 675 nm" and "705 nm and 675 nm" and Chl.a was high (RMSE: about 6g/l). In addition, if the reflectance ratio of 530 nm and 670 nm is used in satellite GCOM/SGLI sensor in the future, the Chl.a in the lake is estimated by 7.2g/l error (linear model).

Effects of Water Environment in Closed Water Body on Diffusion of High-Dissolved-Oxygen Water into Bottom Layer and Its Improvement of Water Quality
Tsuyoshi IMAI1, Tomoyuki MURAKAMI1, Takaya HIGUCHI1 and Masahiko SEKINE2
1 Division of Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University
2 Division of Civil and Environmental Engineering, Graduate School of Science and Engineering, Yamaguchi University
In this study, a method of using high-dissolved-oxygen water to purify bottom sediment in closed body water was confirmed to be effective. In addition, the prevention of phosphorus release from the bottom sediment using high-dissolved-oxygen water was also conducted. A pilot-scale oxygen dissolver was set up at the dam reservoirs in Yamaguchi, Japan and an on-site study was performed at two water quality (the first stages of thermocline formation and the thermocline formation after a month). The results indicated that when starting with the first stages of thermocline formation, it was possible to spread the high dissolved oxygen water across the bottom layer without any diffusion in the upper direction. Furthermore, the existence of high dissolved oxygen water could prevent the release of phosphorus from the bottom sediment. On the other hand, after a month from the thermocline formation, the decrease of the diffusion distance by the production of the brown floc in the pilot-scale oxygen dissolver was detected. Therefore, it is better to introduce the high-dissolved-oxygen water from the first stages of thermocline formation than the thermocline formation after a month. This study revealed the effectiveness of high dissolved oxygen water for the improvement in the water quality of closed body water.

Predominant Factor on Recruitment of Overwintering Microcystis sp. in Dam Lake
Ken USHIJIMA*, Kuniyoshi SHIMA**, Kohji YAMAZAKI**, Toshiaki SHIBATA***, Mitsuo OHSHIMA* and Kenichi YAZAWA****
*: Water Quality Research Division, Water Resources Environment Technology Center
***: MIHARU Dam Operation and Maintenance Office, The Tohoku Regional Bureau, Ministry of Land, Infrastructure, Transport and Tourism(MLIT)
****: NAGAI Dam Construction Office, The Tohoku Regional Bureau, Ministry of Land, Infrastructure, Transport and Tourism(MLIT)
[USHIJIMA Ken] ushijima@wec.or.jp
Microcystis sp. can overwinter on sediment, and it is suspected as one of major source of blooming on next summer. However, the mechanism of recruitment from sediment to water column remains unknown yet. This study tried to find predominant factor(s) of recruitment, excluding physical factors such as resuspension by flow. We observed recruitment in vitro under various condition, which may affect recruitment in actual dam lake. The results showed that; 1.recruitment is observed regardless of dark or light, 2.recruitment is observed regardless of low or high dissolved oxygen, 3.water temperature rise was supposed as one of predominant triggers for recruitment, and threshold temperature proberbly exist between 10 to 15゚C.

Impact of Coexistent Metal Cations on Survival of Diatom in Presence of Polynuclear Hydroxy-Aluminium Ion
Sato Yohei*, ITO Ayumi**, TATE Noriaki***, SASAKI Atsushi**** AIZAWA Jiro***** and UMITA Teruyuki******
*Department of Civil and Environmental Engineering, Graduate School of Engineering, Iwate University
**Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University
***NJS Co., Ltd.
****Technical Devision of Instrumental Analysis, Faculty of Engineering, Yamagata University
*****Technical Devision, Iwate University
******Department of Civil and Environmental Engineering, Graduate School of Engineering, Iwate University
[ITO Ayumi] aitou@iwate-u.ac.jp
[UMITA Teruyuki] umita@iwate-u.ac.jp
The impact of coexistent metal cations on the survival of diatom in the presence of polynuclear hydroxyl-aluminium ion was studied through the cultivation of Nitzschia palea under a weakly acidic condition (pH=6) and the monitoring of chlorophyll a. The presence of Zn higher than 0.2mg/l inhibited the survival of Nitzschia palea without Al. The presence of polynuclear hydroxyl-aluminium ion higher than 0.4mg/l inhibited the survival of Nitzschia palea without Zn. However, the survival of Nitzschia palea was adversely affected by the coexistence with lower level of Zn (0.03mg/l), even though the concentration of polynuclear hydroxyl-aluminium ion was 0.1mg/l. These results indicated that the coexistence of low levels of polynuclear hydroxyl-aluminium and Zn would cause the complex ecological effect on aquatic attached diatom. On the other hand, the coexistence with Ca or Mg higher than 10mg/l attenuated the adverse effect of polynuclear hydroxyl-aluminium ion on the survival of Nitzschia palea. However, the effect of Ca or Mg would be insignificant because their concentrations are lower than 10mg/l in water environment such as rivers.

Effect of extracellular superoxide generation on the growth and iron uptake of Microcystis aeruginosa
Shiori SASAKI*, Manabu FUJII*, **, Hiroaki ITO*, Yoshifumi MASAGO*, T. David WAITE* *and Tatsuo OMURA*
*:Department of Civil and Environmental Engineering, Tohoku University, JAPAN
**:Department of Civil and Environmental Engineering, The University of New South Wales, Australia
[SASAKI Shiori] shiori@water.civil.tohoku.ac.jp
Iron is one of the most important micronutrients for the growth of M. aeruginosa, one of the cyanobacteria forming toxic blooms in closed freshwater systems of the world. Recent studies have shown that the extracellular reduction of ferric iron mediated by superoxide is a key step in the process of iron acquisition by some marine phytoplankton. However, little is known about the iron uptake associated with superoxide generation. We investigated the effect of extracellular superoxide generation on the growth and iron uptake of M. aeruginosa. Our results suggested that superoxide generation associated with cell surface and ferrous iron form can participate in iron uptake.

Evaluation of Allelopathic Effect of Polyphenol to Microcystis aeruginosa by New Bioassay Method
SHIOIRI Mariko*, TAKEDA Fumihiko*, CHIBA Nobuo*, NOMURA Munehiro*, NAKANO Kazunori*, NISHIMURA Osamu*
*Graduate School of Engineering, Tohoku University, JAPAN
[SHIOIRI Mariko] shioiri@eco.civil.tohoku
It was confirmed that allelopathic effect is influenced by nutrient condition. But existing method of algal bioassay system can't exclude the influence of nutrient, because nutrient is added not to be a limiting factor. In this research, we established a new bioassay method that test algae Microcystis aeruginoa could growth without any nutrient, and examined the nutrient influence to the polyphenol's allelopathic effect by the new method. Furthermore the allelopathic mechanism was studied by applying DCMU(3-(3,4-dichlorophenyl)-1,1-dimethylurea) and glucose. As a results, pyrogallic acid(PA) had a allelopathic effect to attack algae cell directly, and the allelopathic effect was enhanced when nutrient exists. It was also revealed that PA inhibits M.aeruginosa from photosynthesizing.

Comparison of Novel Bioassay Method and Previous Method for Ecological Impact Assessment using Microalgae
TAKEDA Fumihiko*, SHIOIRI Mariko*, NOMURA Munehiro*, NAKANO Kazunori* and NISHIMURA Osamu*
*Graduate School of Engineering, Tohoku University
[TAKEDA Fumihiko] takeda@eco.civil.tohoku.ac.jp
[NISHIMURA Osamu] osamura@eco.civil.tohoku.ac.jp
Novel bioassay method that test microalgae can show the maximum specific growth rate μmax regardless of nutrient conditions in test water was constructed. The method and a previous bioassay method was compared based on the evaluation of growth-inhibiting effect by the extracts and culture solution of a brown alga Sargassum horneri using diatom Skeletonema costatum. As a result, the growth-inhibiting effect of the extract in a previous bioassay method was underestimated compared to that in the novel bioassay method, which would be because of the long-term bioassay period and the decrease of the growth-inhibiting effect by the addition of nutrients to test water in a previous method. Since a previous bioassay method is indispensable to add nutrients to test water to avoid the nutrient limitation for the growth, it was revealed that a previous method cannot make the appropriate evaluation of chemical toxicity. Therefore It was considered that the novel bioassay method is useful to apply for the ecological impact assessment of chemicals because the method is possible to evaluate a growth-inhibiting effect without the addition of nutriets to test water.

Risk evaluation for waterborne infectious diseases based on seroprevalence in rural Cambodia
SASAKI Tsukasa*, WATANABE Toru**, MIURA Takayuki*, MASAGO Yoshifumi*, NAKAMURA Satoshi***, OMURA Tatsuo*
*: Department of Civil and Environmental Engineering, Tohoku University, JAPAN
**: Department of Civil, Architectural and Environmental Engineering, Drexel University, USA
***: Research Institute, International Medical Center of Japan, JAPAN
[WATANABE Toru] to-ru@water.civil.tohoku.ac.jp
A risk evaluation framework of waterborne infectious diseases based on seroprevalence was developed and used to evaluate risk of infection by Campylobacter jejuni, Helicobacter pylori and adenoviruses in two villages in rural Cambodia. As the result, it was revealed that no outbreak of campylobacteriosis occurred in recent years. It was also revealed that almost all villagers would be infected by adenovirus in the first five years of their lives. As for H. pylori infection, a high annual risk of infection (8 to 10%) was estimated and drinking water contamination with total coliform was found to be a significant risk factor (O.R. = 5.29, 95 % C.I. = 1.17 to 23.9). Although a part of villagers drank well water heavily contaminated with arsenic, the effect of arsenic on disturbing their production of serum antibody against H. pylori was negligible.

Distribution of antibiotic-resistant bacteria in aquatic environments in Miyagi prefecture
Eri NAKAO*, Kazunori NAKANO*, Munehiro NOMURA*, Nobuo CHIBA*, Osamu NISHIMURA*, Setsu WATANABE**, Tomonori NAKAMURA**, and Takashi HATAKEYAMA**
*:Graduate school of Engineering, Tohoku University,Japan
**:Miyagi Prefectural Institute of Public Helth and Environment,Japan
[NAKAO Eri] nakao@eco.civil.tohoku.ac.jp
Actual situations concerning the distribution of antibiotic-resistant bacteria in aquatic environments around livestock area in Miyagi prefecture were investigated. Four selective plates to isolate bacteria derived from feces indicating wastewater pollution by livestock farms and indigenous bacteria in the aquatic environments were used to examine the existing ratio of antibiotic-resistant bacteria to ampicillin, kanamycin, oxytetracycline and chloramphenicol. As a result, resistant bacteria to these antibiotics were extensively found in indigenous bacteria as well as intestinal bacteria derived from livestock farm. Their distribution was confirmed not only at down-flow area of livestock farm, but also at up-flow area without livestock farm. The relationships between the ratio of antibiotic-resistant bacteria and wastewater pollution by livestock farms were indicated by correlation with intestinal bacterial number. Although some indigenous antibiotic-resistance was observed, the ratio of antibiotic-resistant bacteria was unusually high at some investigation sites. Potential causes for high ratio of antibiotic-resistant bacteria were discussed.

Microarray analysis of eubacterial community and bacterial pathogens inleachate from three different landfills of Japan
UPADHYE Rahul R.*, INOUE Daisuke*, ISHIGAKI Tomonori**, SEI Kazunari*,Michihiko IKE*
*:Division of Sustainable Energy and Environmental Engineering, Osaka University,JAPAN **:Department of Environmental Solution Technology, Ryukoku University,JAPAN
[IKE Michihiko] ike@see.eng.osaka-u.ac.jp
Eubacterial communities and bacterial pathogens occurring in the leachatescollected from three full-scale landfills in mesothermal area of Japanwere analyzed using DNA microarrays targeting approximately a thousandeubacterial and pathogen species/groups. The leachate samples showed almostsimilar eubacterial compositions with marginal variations. Comparison ofthe results with precedents suggested that the predominant eubacterialpopulations in the landfills may be generally similar in East and SoutheastAsia, irrespective of the climate zone. Analysis of the bacterial pathogensshowed that the three leachates included a total of 44 species/groups ofbacterial pathogens and 26 species/groups including Francisella, a frankzoonotic pathogens causing a serious health risk, and other high-risk pathogenswere commonly found. In addtion, the 2 leachate samples from the landfills,where organic wastes such as sludge and raw garbage were mainly disposed,had 15 specific pathogens. It was suggested that sludge can increase thevariation of the pathogens occurring in landfill leachates. Overall, resultsof this study posed some insights into the underlying microbial ecologyin the landfill and the possible microbiological health risks associatedwith the landfill leachate.

Impacts of a Foreign Bacterium on Indigenous Microbial Community: Examination of Evaluation Method
1:Dept. of Civil and Environmental Engineering, Tohoku Gakuin University
2:NS Environmental Science Consultant Corporation
Impacts of Cupriavidus necator KT1 on indigenous bacterial community in river water were examined by batch experiments. Three sets of river water samples, that contain strain KT1 of 1, 10, and 50% of total bacteria in river water, were prepared respectively. Changes of microbial community composition were analyzed. A control analysis was also conducted without KT1 addition. Only the 16S rRNA gene of strain KT1 added was decreased remarkably within 5 days. As a result, indigenous bacterial community composition was restored in a short time. A grazing experiment was carried out by using strain KT1. A high concentration of strain KT1 culture was added to a river water. A rapid decrease of strain KT1 was observed, and a flagellate was found to graze strain KT1. The flagellate may play an important role in preserving a natural ecosystem.

Use of GST activity as an evaluation tool for air pollution
Kiyo Hasegawa-KURISU*, Michitaka HAMA** and Keisuke HANAKI**
*Research Center for Advanced Science and Technology, the University of Tokyo
**Dept. of Urban Engineering, the University of Tokyo
[Kiyo H. Kurisu] kiyo@env.t.u-tokyo.ac.jp
[Keisuke Hanaki] hanaki@env.t.u-tokyo.ac.jp
It was investigated whether GST (glutathione-S-transferase) activity in plant leaves can be used as a biomarker of air pollution or not. As the first step, effective protein extraction method and temperature of GST-activity measurement were checked. Using the determined extraction and measurement method, GST activities of Pothos (Epipremunum aureum ) exposed by road- or tobacco-pollutants were analyzed. The leaves exposed by environmental tobacco smoke in about one month showed significantly high GST activities than that of the control. It indicated the possibility of GST in plant leaves as a biomarker of air pollution, but further investigation especially about influencing factors is needed.

Biological Oxidation of Arsenite by Bacteria Isolated from Activated Sludge
ANDRIANISA Harinaivo Anderson*, ITO Ayumi**, Miura Jun-ichi***, Aizawa Jiro**** and UMITA Teruyuki*
*Department of Civil and Environmental Engineering, Iwate University
**Department of Frontier Materials and Function Engineering, Graduate School of Engineering, Iwate University
***Department of Civil and Environmental Engineering, Graduate School of Engineering, Iwate University
****Technical Devision, Iwate University
[ITO Ayumi] aitou@iwate-u.ac.jp
[UMITA Teruyuki] umita@iwate-u.ac.jp
In this study, the isolation of arsenite oxidising bacteria from activated sludge was investigated through subculture using the mineral medium contaning high concentration of arsenite. Arsenite was biologically oxidised to arsenate by bacteria in the activated sludge and two kinds of bacteria were isolated. One of the bacterium isolated from the activated sludge could grow by oxidising arsenite and was most closely related to Ensifer adhaerens (homology: 99.9%). The other could not oxidize arsenite and was related to Microbacterium keratanolyticum (homology: 99.5%). The oxidation rate of arsenite by the isolated arsenite oxidising bacteria followed the Michaelis-Menten’s model and the maximum reaction rate and the Michaelis constant were 1.74×10-9µg/cell/min and 415µg/L, respectively. Furthermore, the coexistence of lactate as an organic carbon source accelerated the oxidation rate of arsenite by the bacteria.
It was concluded that the arsenite oxidising bacterium isolated in this study can be utilized for the remediation of groundwater and wastewater contaminated with arsenite.

Development of a novel DNA Extraction Method based on Sonication followed by Dilution for the Microbial Community Analysis of Activated Sludge Samples
Hiroyasu SATOH*, Motoharu ONUKI**, and Takashi MINO*
*) Institute of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo
**) Integrated Research System for Sustainability Science, The University of Tokyo
For the analysis of microbial population in activated sludge samples, significant cost and time are spent for the extraction of DNA from cells. In the present study, DNA was first extracted from samples by sonication, and the crude extract was subjected to PCR (polymerase chain reaction). When the sonicated sample was diluted to around 1,000 to 10,000 times, PCR products were obtained. For the same sample, DNA was extracted by the present method and one of the commersial DNA extraction-purification kits using beads beating, and was subjected to T-RFLP (Terminal-Restriction Fragment Length Polymorphism) analysis targetted at a partial sequence of 16SrRNA gene. While the obtained fragment patterns had differences, it was found the present method can be applicable for at least some part of bacteria. It is worth to improve the present method by further research and development, as it is extremely simple.

Identification of Phenol-Assimilating Microorganisms under Aerobic Conditions in A Coke Oven Wastewater Treatment System by Comparative Stable Isotope Probing of RNA
SUEOKA Kazuo*, ONUKI Motoharu**, SATOH Hiroyasu*, MINO Takashi*, **
* Graduate School of Frontier Sciences, Chiba, Japan
** Integrated Research System for Sustainability Science (IR3S), Tokyo, Japan
Stable isotope probing of RNA (RNA-SIP) was applied for the identification of phenol-assimilating microorganisms in activated sludge treating a synthetic coke oven wastewater. The RNA-SIP method is a culture-independent method using stable isotope-enriched substrates that be able to link the identity of microorganisms with their function in the environment. The activated sludge was fed with 13C-labeled phenol (300 mg per l) and ribonucleic acids of phenol-assimilating microorganisms were labeled with 13C. The 13C-RNA was extracted from the samples, fractionated by ultracentrifugation, and analyzed by terminal restriction fragment length polymorphism, and the selected fractions were further analyzed by cloning and sequencing. These analyses showed that the bacteria assimilating 13C derived from the 13C-labeled phenol were the Betaproteobacterial Thauera genus, the Gammaproteobacterial Marinobacterium and Halomonas genera, and the Actinobacterial Propionibacterium genus.

Adsorption characteristics of heavy metals on mixture of andisol and waste iron powder as cover soil barrier
Kazuyuki Suzuki*, Takeshi Yoshioka**, Yoshiro Ono**
* Faculty of life applied science, Nigata University of Pharmacy and Applied Life Science, JAPAN **Graduate School of Environmental Science, Okayama University, JAPAN
[Kazuyuki Suzuki] kazuyuki@nupals.ac.jp
This study is an attempt at development of low-cost and effective technologies for leachate treatment using cover soil. A mixture of andisol and waste iron powder was selected as cover soil for adsorption of heavy metals in landfill leachate. Batch adsorption experiments were performed to assess the performance of andisol and waste iron powder for heavy metal adsorption under various conditions (pH, temperature, etc.). The adsorption of heavy metals on both adsorbents was well described using Freundlich isotherm equation model. Andisol and waste iron powder have high adsorption capacity. For pH 4-6, the Freundlich constant KF of both adsorbents remained almost constant. The Freundlich constant KF, which reflects the adsorption capacity, increased with increasing temperature to 353 K. Thermodynamic parameters were calculated. The thermodynamic parameters of adsorbents shows the endothermic and spontaneous nature of the process. Using these results, it was concluded that the mixture is useful as cover soil for removal of heavy metals from leachate. Column adsorption experiments were performed using the mixture for determination of kinetic parameters under a dynamic adsorption process. The Bohart and Adams model showed a better fit for Cu, Pb and Zn. In the bed depth service time (BDST) model, the adsorption capacity N0 and rate constant k are obtainable.

MSW incineration ash from water-washing treatment and leaching behavior of some elements
YAMASHITA Taishi*, MIZUTANI Satoshi*, KANJO Yoshinori*
*:Graduate School of Engineering,Osaka City University, JAPAN
[MIZUTANI Satoshi] miz@urban.eng.osaka-cu.ac.jp
Water-washing treatment for MSW incineration bottom ash and fly ash were studied. Column test and the availavility test were performed in order to evaluate the long-term leaching behavior and washing effect. Increasing the frequency of washing is more effective for promoting elution rather than a liquid per solid ratio (L/S) or elution time. The cumulative amount of leaching in a column test was controlled to about 1/2~1/10 by water-washing for TOC and soluble salts such Na, Ca, K, and Cl-. On the other hand, removing heavy metals such as Cd were difficult.

Measures to Prevent Emissions of Hazardous Materials from Crematoriumsin Japan
TAKEDA Nobuo*, TAKAOKA Masaki**, OSHITA Kazuyuki**
*: Eco-Technology Research Center, Ritsumeikan University, JAPAN
**: Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, JAPAN
[TAKAOKA Masaki] takaoka@environ.mbox.media.kyoto-u.ac.jp
This study measured hazardous materials, including dioxins, mercury, and hexavalent chromium compounds, in the flue gases, fly ash, and bottom ash from four crematoriums in Japan, to evaluate the emissions from crematoriums.
The toxic equivalent concentration (normalized by 12% O2) of dioxins in the flue gases from crematoriums ranged from 0.00012 to 1.2 ng-TEQ/m3N. The estimated maximum emission inventory of dioxins from crematoriums was 1.1 g-TEQ/year, which is less than one-fifth of the present emission inventory. Although mercury in flue gases from crematoriums was under the minimum limit of determination using the JIS K0222 method, Hg0 from dental amalgam contributed significantly to the total mercury emissions from crematoriums based on a continuous mercury speciation analyzer, as in our past study. The hexavalent chromium compounds leached from all ash samples exceeded the Japanese environmental quality standards for soil by 180 to 1,200 times. Therefore, countermeasures against hexavalent chromium compounds in the ash from crematoriums are required.

Investigation of material separation of mixed construction and demolition waste by sorting process
Alonso Montero*, Yasumasa TOJO*, Takayuki MATSUO*, Toshihiko MATSUTO*, Masato YAMADA**, Hiroshi ASAKURA**, and Yusaku ONO***
*:Graduate school of Engineering, Hokkaido University, Japan
**: National Institutes for Environmental Studies, Japan
***: Center for Environmental Science in Saitama, Japan
The final disposal ratio of mixed construction and demolition waste (MCDW) remains high in Japan, while progress has been made in the recycling of other construction and demolition waste. Sorting facilities are expected to play an important role in better management of MCDW. In this study, the feasibility of sorting facilities for the separation of material and of pretreatment for final disposal was investigated by conducting a batch experiment at a real operational facility. The material flow of each output fraction was determined based on the mass distribution and on analysis of the ignition loss and metal content. The separation of organic matter and ferrous metal achieved by the sorting process was excellent; almost 70% was separated out for recycling and did not go for disposal. Although the distribution ratios of heavy metals, such as Pb and Zn, sent to landfill were still high, their content little changed from the condition of the original mixed waste. The process of sorting MCDW achieved reduction of mass for disposal, reduction of the organic load directed to the landfill, and the diversion of iron from MCDW to recycling.

Empirical Study of Waste Disposal Charge in Tottori Prefecture
‐A CGE Model in the context of the Household Production function ‐
Atushi KOIKE*,Yumiko YAMAGUCHI*,Yoshihiko HOSOI*
*Department of Social System Engineering, Tottori University, JAPAN
[Atushi KOIKE]koike@sse.tottori-u.ac.jp
The Local governments in Japan should make a plan to dispose to the municipal solid waste. The waste management law provides that local government can collect the cost for waste management to the people. By this content, the case of introducing garbage fee by local government was increased. Especially, waste disposal charge will be more populer. This study aims to analyze the economic effects by the waste disposal charge in Tottori prefecture. We builded a CGE Model in the context of the household production function. Especially, we build consumer behavior model in oder to deal with waste reduction activity time. The conclusion of this study is that waste disposal charge is effective municipal solid waste reduction.

Comparison of Decolorizatin Efficiency of Waste Water Using Streamer Didchage and Ozonization
TAKAHASHI Katsuyuki*, SATO Taiki*, NAITO Jun*, MUKAIGAWA Seiji*, TAKAKI Koichi*, FUJIWARA Tamiya*, SATTA Naoya**
*:Department of Electrical and Electronic Engineering, Iwate University, JAPAN
**:Department of Environmental Sciences for Sustainability, Iwate University, JAPAN
[TAKAHASHI Katsuyuki] t3307019@iwate-u.ac.jp
Water purification using a pulsed power discharge in water and ozone generated by dielectric barrier discharge(DBD) have been investigated experimentaly. Solutions contained Acid Red 1 and Acid Blue 64 were used as a specimen. A stacked Blumlein line pulsed power generator and wire-to-plane electrode was employed to generate the discharge in the water. The ozone of 1500 ppm cocentration was generated using pulse modulator driven coaxial cylinder DBD reactor and was injected to the solution. The electric powers consumed in reactors were 3 W and 8 W for water discharge and DBD, respectively. Acid Red 1 was successfully decolorized with 30 min of the ozonation process. The peak of the absorbance spectra shifted to higher value through the discharge in the water. The decoloration efficency of Acid Blue 64 by the ozonation process was about 1.1 times higher than that using the discharge in the water. The total organic carbone(TOC) removal was achieved to about 20% by the ozonation process.

Characterization of pretreated palygorskite for ammonia gas adsorption
ZHANG Qiong*, HIGUCHI Takaya*, SEKINE Masahiko*, IMAI Tsuyoshi*
*Graduate School of Science and Engineering, Yamaguchi University, Japan
[HIGUCHI Takaya] takaya@yamaguchi-u.ac.jp
Palygorskite, which is one of magnesium aluminum silicate, was investigated as adsorbent to adsorb ammonia gas in this study. The palygorskite was pretreated with HCl, HNO3 or NaOH with different concentration, temperature and reaction time. Raw palygorskite and pretreated ones were characterized with specific surface area by Brunauer-Emmett-Teller method, crystal structure by X-ray diffraction and metal dissolution by inductively coupled plasma-optical emission spectroscopy. Adsorption experiments were carried out at room temperature with an initial ammonia concentration in the range of 150-3000 ppm in nitrogen carrier gas. The adsorption capacity of ammonia was investigated by the 10% breakthrough time. The results showed that palygorskite had excellent adsorption property for adsorbing ammonia. The sample HCl-352 pretreated with 3 mol/l of HCl at 50°C for 24 hours had the highest adsorption capacity of 17.2 mg/g.

A Study on Removal Characteristics and Effect Factors of Removal of Persistent Perfluorinated Compounds by Powdered Activated Carbon
Koji KIMURA1*・Shigeo FUJII2・Shuhei TANAKA1・Yong QIU 1・Munehiro NOZOE1
1Research Center for Environmental Quality Management, Graduate school of Engineering, Kyoto University
2Department of Technology and Ecology, Graduate School of Global Environmental Studies, Kyoto University
Adsorption removal of eight perfluorinated compounds by powdered activated carbon was studied. In single-solute solutions, adsorption equilibrium constant K were calculated as 22.33 for PFOS, and 14.48 for PFOA. Substances with longer carbon chain were removed better, suggesting the relation of adsorption removal with their hydrophobicities. In mixed solution of the eight compounds, the removed amount of three compounds: PFDA, PFDoA, and PFOS was decreased to 80 % of single-solute solution, whereas for the other five: PFHxA, PFHpA, PFOA, PFNA, and PFHxS, the amount decreased to less than half. The effect of dissolved organic matters was also investigated by using Lake Biwa water as the solvent of the mixed solution. The removal of PFOS and PFHxS was not greatly affected and the removed amount decreased by 60 %. However, the other five compounds were scarcely removed, showing irregular temporal concentration changes.

Effect of further pulverization of powdered activated carbon on adsorption equilibrium and kinetics
Naoya ANDO*, Yoshihiko MATSUI*, Taku MATSUSHITA*, Koichi OHNO*, Hiroshi SASAKI* and Yu NAKANO*
*:Division of Built Environment, Graduate school of Engineering, Hokkaido University, JAPAN
[Naoya ANDO] n-ando@eng.hokudai.ac.jp
Batch adsorption experiments using powdered activated carbon (PAC) and submicron-powdered activated carbon (S-PAC) were conducted for natural organic matter (NOM), polystyrene sulfonates (PSS) and polyethylene glycols (PEG). Pulverization of PAC to submicron size increased adsorption capacity of NOM. Increase in adsorption capacity tended to be substantial for compounds with higher molecular weight, but highly depended on the type of compounds. The homogeneous surface diffusion model (HSDM) simulation revealed that factors mainly contributing to the increase in adsorption kinetic with the pulverization also depended on the type of compounds: the predominant factor for PSS was the increase in adsorption capacity, whereas that for PEG was the increase in specific surface area of the activated carbon.

Process Performance of Non-aerated Nitrification Process by DHS reactor
KEN Hattori*, TOSHIHIRO Kochizawa*,**, YUSUKE Watanabe*, MADAN Tandukar*,***, KENGO Kubota*, LI Yu-You* and HIDEKI Harada*
*:Dept.of Civil and Environmental Engineering, Tohoku University,JAPAN
**:Organo Corporation,JAPAN
***:Dept. of Civil & Environmental Engineering, Georgia Institute of Technology Atlanta, GA, US
The objective of this study is to evaluate applicability of DHS reactor to nitrification process receiving a high strength ammonium influent. The most prominent advantage of DHS reactor is no need for external aeration because sponge carriers are exposed to air. DHS reactor in this study was operated with an artificial wastewater composed of ammonium-nitrogen solely (completely organic free) at ambient temperature. The total experimental period of 350 days was divided into 4 phases according to ammonium-nitrogen loading rate. The maximum nitrification rate of 1.78 kg-N·m-3·d-1 was observed at a HRT of 6 h and at an ammonium-nitrogen loading rate of 2.00 kg-N·m-3·d-1. The maximum oxygen uptake rate was estimated from nitrogen elimination rate to be 66 g-O2·g-VSS-1·d-1. Nitrification potential of DHS reactor was verified to be comparable to other types of nitrification processes equipped with external aeration. There is a need of further investigation to enhance the nitrification performance by overcoming the restriction of partial oxygen permeation into carrier-sponge inward depth.

Biodegradation of Wastewater of Synthetic Resin containing Polyvinyl Alcohol (PVA) using a UASB-DHS system
Ryoko TANIGUCHI *, Akinori IGUCHI*, Tadashi TAGAWA**, Shinichi YAMAZAKI***, Nobuo ARAKI ****, Hiroyuki IMACHI*****, and Takashi YAMAGUCHI*
*Dept. of Environmental system Engineering, Nagaoka University of Technolog
** Dept. of Civil Engineering, Takamatsu National College of Technology
*** Dept. of Civil Engineering, Kochi National College of Technology
**** Dept. of Civil Engineering, Nagaoka National College of Technology
***** Extremobiosphere Research Center, Japan Agency for Marin-Earth Science and Technology (JAMSTEC)
[TANIGUCHI Ryoko] ryoko@stn. nagaokaut. ac. jp
A UASB (Up-flow Anaerobic sludge Blanket)-DHS (Down-flow Hanging sponge) system has been operated for degradation of wastewater containing polyvinyl alcohol (PVA), the water-soluble polymer which is commonly used in textile industry. Anaerobic organisms has been applied to the UASB reactor to investigate the biodegradation of easily decomposable organic matter and depolymerization of PVA . The results of clone analysis targeting all bacterium of 16S rRNA, Bacteroidetes were predominant species in the UASB reactor. Putative PVA degrading bacteria such as Alcaligenes sp., Pseudomonas sp., Azoareus sp., Xanthomonas sp. were detected in the DHS reactor.

Development of anaerobic digestion of kitchen garbage and sewage sludge using hyperthermophilic acidification
Myung Yeol LEE*, Taira HIDAKA* and Hiroshi TSUNO*
*:Dept. of Urban and Environmental Engineering, Kyoto University
[Taira HIDAKA] hidaka@water.env.kyoto-u.ac.jp
Among various methods used for the treatment of kitchen garbage and excess sludge, anaerobic digestion is a promising technology with energy recovery, but required to be more effective. An anaerobic digester system that consists of an acidogenic reactor operating at hyperthermophilic condition and a methanogenic reactor in series was discussed. Lab-scale reactors were operated continuously fed with artificial kitchen garbage or co-substrate composed of artificial kitchen garbage and excess slude. At the acidification step, protein solubilization ratio at 70°C was higher than that at 55°C. It was suggested that the process composed of acidogenesis at 70°C and methanogenesis at 55°C is useful to increase methane production and process stability. By batch experiments, it was proved that this process had both biological and physical effects, and had higher treatment performance than heat treatment only.

Modeling of Dissolution/Precipitation of Inorganic Compounds in Anaerobic Digestion of Municipal Sludge
KOMATSU Kazuya*, YASUI Hidenari**, Li Yu-You***, NOIKE Tatsuya****
*:R&D division, Kurita Water Industries ltd., JAPAN
**:Faculty of Environmental Engieering, The University of Kitakyushu, JAPAN
***:Graduate School of Engineering, Tohoku University, JAPAN
****:Advanced Research Institute for the Science and Humanities, Nihon University, JAPAN
[KOMATSU Kazuya] kazuya.komatsu@kurita.co.jp
Recently, anaerobic digestion is re-apprised as treatment process of municipal sludge and many studies are conducted to develop new technologies to improve digestion efficiency. Inorganic ratio in digested sludge increases as more organic components are degraded by improvement of digestion efficiency, and their dissolution/precipitation have more effects on the process performance, such as dewaterability of digested sludge. However, inorganic dissolution/precipitation reaction is excluded in modeling of anaerobic digestion process due to the complexities of the process. Since digested sludge analysis revealed that phosphoric anhydride occupied one-fourth of total ash content and main soluble components were PO4-P, Ca and Mg, the mathematical model for prediction of inorganic dissolution/precipitation in anaerobic digestion was composed based on the reported prediction model of recycle phosphorus loads from anaerobic digestion. By considering the solubility products of precipitated phosphate and modifying release rate of Ca and Al from feed sludge components in the reported model, it was possible to calculate soluble PO4-P, Ca and Mg concentration in the digested sludge based on inorganic composition of feed sludge and digester operating conditions.

Genetic Diversity and Amino Acid Substitutions among Norovirus Genogroup II Strains in Environmental and Stool Samples
Takahiro Imai1, Daisuke Sano2,Yoshifumi Masago1, You Ueki3,Kensuke Fukushi4 and Tatsuo Omura1
1 Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University
2 Department of Microbiology, School of Biology, University of Barcelona
3 Miyagi Prefectural Institute of Public Health and Environment
4 Transdisciplinary Initiative for Global Sustainability, The University of Tokyo
Capsid gene sequences of norovirus GII were acquired from patients of gastroenteritis, primary-treated wastewater, activated sludge, secondary-treated wastewater, river water, seawater and oyster in geographically close areas between 2001 and 2006. Most of the norovirus GII genes acquired from gastroenteritis patients were mainly categorized into GII.3 and GII.4. On the other hand, diverse genotypes of norovirus GII including GII.2, 3, 4, 5, 10, 11, 14 and 15 were obtained from environmental samples. Amino acid sequences of norovirus GII.4 obtained in this study were compared with that of norovirus GII.4 Bristol. As a result, amino acid substitutions were observed in the 8th (Ala), 9th (Asn), 15th (Ala) and 54th (Asn) residues. The analysis of amino acid substitutions and investigation of the appearance of norovirus mutants could be useful to understand the dynamics of norovirus in human society.

Use of Murine Norovirus as a Novel Surrogate to Evaluate Resistance of Human Norovirus to Free Chlorine Disinfection in Drinking Water Supply System
KITAJIMA Masaaki1, TOHYA Yukinobu2, MATSUBARA Koichi1,3, HARAMOTO Eiji4, UTAGAWA Etsuko5, KATAYAMA Hiroyuki1, OHGAKI Shinichiro1
1Dept. of Urban Engineering, The University of Tokyo
2Dept. of Veterinary Medical Science, The University of Tokyo
3Water Supply Dept., Nihon Suido Consultants Co.
4Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi
5Dept. of Virology II, National Institute of Infectious Diseases
Human noroviruses (NoVs) are a major cause of viral gastroenteritis outbreaks worldwide and commonly transmitted via the fecal-oral route through contaminated food or water. Due to the lack of cell culture system for NoVs, little knowledge is available on the resistance of NoVs to various disinfectants. In this study, cultivable murine norovirus (MNV) was used as a surrogate to evaluate resistance of NoVs to chlorination in drinking water supply system. MNV, NoV, and poliovirus type 1 (PV1) were inoculated into treated water collected from a drinking water treatment plant, followed by free chlorine disinfection. MNV was inactivated more than 99.99% (4 log) with the Ct value of 3 mg/L-min, showing less resistance to free chlorine than PV1. Based on TaqMan real-time RT-PCR analysis, the reduction rate of NoV genogroup II (Lordsdale strain) was comparable to that of MNV. These results indicate that NoVs are not highly resistant to free chlorine disinfection compared with other enteric viruses and that NoV-infection via drinking water supply system can be controlled with adequate chlorination.

Occurrence of Cryptosporidium and Giardia in Tributary Rivers of the Tonegawa River Basin
HARAMOTO Eiji*, YONASHIRO Yuji**, AKIBA Michihiro**, HASHIMOTO Atsushi***, MORITA Shigemitsu****, ASAMI Mari**, KUNIKANE Shoichi*****
*:Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, JAPAN
**:Department of Water Supply Engineering, National Institute of Public Health, JAPAN
***:Department of Civil Engineering, Anan National College of Technology, JAPAN
****:School of Life and Environmental Science, Azabu University, JAPAN
*****:Institute for Environmental Sciences, University of Shizuoka, JAPAN
[HARAMOTO Eiji] eharamoto@yamanashi.ac.jp
The objective of this study was to determine the occurrence of Cryptosporidium and Giardia in river water used for drinking water. Twenty-three river water samples were collected at 7 sites in tributary rivers of the Tonegawa River basin in Japan from October 2007 to February 2008. Cryptosporidium and Giardia were detected in 21 (91%) and 18 (78%) of the 23 samples (10 liters each), showing the highest concentration of 790 oocysts/10 L and 37 cysts/10 L, respectively. A single Cryptosporidium oocyst was isolated from the concentrated river water sample by using micromanipulation technique, followed by DNA extraction and nested PCR of the 18S rDNA gene. Fifty-six (15%) out of 376 single-oocyst samples were positive for the Cryptosporidium 18S rDNA gene, and subsequent direct DNA-sequencing revealed the presence of four genotypes: C. suis (48 samples, or 8 strains), C. andersoni (5 samples, or 4 strains), C. pig genotype II (2 samples, or 2 strains), and C. meleagridis (1 sample, or 1 strain).

Relationship Between Land Use and Coliphage Concentration in Rivers - A Case Study in Gifu City -
SASAJIMA Yasuhiro*, YOSHIMURA Chihiro**, LI Fusheng***
*:Dept. of Civil Engineering, Graduate School of Engineering, Gifu University, JAPAN
**:Dept. of Civil Engineering, Faculity of Engineering, Gifu University, JAPAN
***:River Basin Research Center, Gifu University, JAPAN
[SASAJIMA Yasuhiro]m3121011@edu.gifu-u.ac.jp [YOSHIMURA Chihiro]yoshi_c@gifu-u.ac.jp [LI Fusheng]lifs@gifu-u.ac.jp
This study focused on the relationship between land use and coliphage concentration in rivers in Gifu city. We sampled river water at 20 sites along four urban rivers and analyzed water chemistry and concentrations of F-RNA and somatic phages and Escherichia coli. Coliphage concentrations were the highest along agricultural land followed by urban area and forest. River section receiving treated sewage water showed lower coliphage concentration than that without treated sewage water in urban area. This study revealed that pathogenic virus concentration is higher in suburb, agricultural and residential areas, than in the city center, which implied diffuse pollution of pathogenic virus in water environment.

Analysis of Denitrifying Community Structure in a Combined System of Two-step UASB Reactor and Aerobic Biofilm Reactor
KAMIMURA Motonari*, ARAKI Nobuo*, HAMAGUCHI Takemasa**, YAMAZAKI Shinichi**, SYUTSUBO Kazuaki***, YAMAGUCHI Takashi****
*: Department of Civil Engineering, Nagaoka National College of Technology, JAPAN
**: Department of Civil Engineering, Kochi National College of Technology, JAPAN
***: Water and Soil Environmental Division, National Institute for Environmental Studies, JAPAN
****: Department of Environmental System Engineering, Nagaoka University of Technology, JAPAN
[ARAKI Nobuo] araki@nagaoka-ct.ac.jp
We have proposed a newly sewage treatment system by combining a two-step of anaerobic UASB (for removal of organics and denitrification) and an aerobic biofilm reactor in order to diminish energy requirements and excess sludge production as enhancing sulfur-redox cycle. Analysis of microbial community structure on denitrifying bacteria was carried out by combining of molecular tools and vial activity tests of retained sludge in the second UASB. PCR-denaturing gradient gel electrophoresis (DGGE) was revealed that both Thiobacillus denitrificans and Acidovorax avenae coexisted as a predominant species of nitrate-reducing sulfur-oxidizing bacteria (NR-SOB) and heterotrophic denitrifying bacteria (ODB), respectively. Hydrogen-utilizing sulfate-reducing bacteria (SRB) also present in the UASB as establishing symbioses through sulfur compounds with NR-SOB. Additional influent of wastewater to the UASB likely activated not only ODB but also SRB, leading growth of NR-SOB. It was estimated that NR-SOB contributed 80% of over all of nitrogen removal from the UASB, enabling the high denitrifying efficiency of the whole system.

Detection of Aromatic Hydrocarbon-Degrading Bacteria in Activated Sludge using Microautoradiography-Fluorecence In Situ Hybridization
TANABE Yasuto*, TOMONORI Kindaichi**, NORIATSU Ozaki**
*:IDEA Consultants, Inc., JAPAN
**:Dept. of Social and Environmental Engineering, Hiroshima University, JAPAN
[TANABE Yasuto] tnb20812@ideacon.co.jp
Benzene and polycyclic aromatic hydrocarbons (PAHs) are toxic chemical compounds in the petroleum-contaminated site. Bioremediation is useful technique that can remove these chemical compounds. In order to establish bioremediation technique, it is important to identify degradation bacteria. In this study, to enrich PAHs-degrading bacterial community, activated sludge was incubated with PAHs (benzene, naphthalene, phenanthrene) as the sole source of carbon. Phylogenetic analysis and MAR-FISH analysis revealed that Acinetobacter sp. is capable of degradation of benzene and member of Betaproteobacteria and Gammaproteobacteria are capable of degradation of naphthalene and phenanthrene.

Evaluation of the density of microorganisms in Nagara River water
system by plate culture and real time PCR methods
Nobuo HARATA*, Fusheng LI **, Maya ITO***, Yoshihiro KATAMINE **** and Chihiro YOSHIMURA *****
*Graduate Student of Engineering , Gifu University
**River Basin Research Center, Gifu University
***Daisin Seiko Co., Ltd.
****Fusou Water Industries Co., Ltd.
*****Department of Civil Engineering, Gifu University
Microorganism inhabited in river water system is an important factor affecting river ecosystems and river water qualities. In this study, the density of microorganisms in Nagara River water system was evaluated by real time PCR method and the plate culture method for river water and the riverbed sediment field collected from the mainstream of the Nagara River and its seven major tributaries. The results indicated that the density of microorganisms in the river water phase increased as water flowed downstream, however, that in the riverbed sediment phase did not change significantly. Water quality seemed to be in close relation with the density of microorganisms. In addition, the relationship between total microorganisms (defected by the real time PCR method) and viable cells (defected by the plate culture method) differed with field study points, suggesting that microorganisms were affected by water qualities at those study points and seasons.

Seasonal Changes in Bacterial Community Composition of the Hirose River
Kanji NAKAMURA1, Miki HAMAYA1, Emi AIZAWA1, 2, Shintaro ABE1, 3, Takeshi KAWAGUCHI1, 3
1:Dept. of Civil and Environmental Engineering, Tohoku Gakuin University
2:Nihon Setsubi Kogyo Corporation
3:Shibuya Construction Corporation
Bacterial populations in the Hirose river were analyzed through a year. Eight sampling points (Sp) were set along the whole river. Bacterial 16S rRNA gene in river water was quantified by real-time PCR. The gene concentration ranged from 2×105 to 4×105 copies/mL at the uppermost stream point. The gene concentration increased toward downstream, and reached 2×106 to 3×107 copies/mL at the downmost stream point. The increase of 16S rRNA gene copy number was significant in summer. Bacterial population analysis was conducted by Terminal Restriction Fragment Length Polymorphism (T-RFLP). Changes in bacterial community composition were observed in the upstream region. The composition was rather stable in the midstream and the downstream region, however, gradual changes in the composition were observed when water temperature increased.

Alkali Release from Thermal Treatment Residues
Yutaka DOTE* and Tomoo SEKITO*
*:Dept. of Civil and Environmental Engineering, University of Miyazaki
[Yutaka DOTE]dote@civil.miyazaki-u.ac.jp
In order to clear the phenomena of alkali release from thermal treatment resides after washing off the easily soluble matter, a sequential leaching test of bottom ash (BA), stabilized fly ash (SFA) and slag was conducted with a nitric solution (pH=4). The total alkalinity (TA) in leachate was kept constant with time. The TA at the last sampling was 3-40 meq/L for BA and SFA and 0.1 meq/L for the slag. More than 97 % of TA of BA and SFA consisted of residual alkalinity (RA), which was composed of OH- and IC. TA for BA and SFA was reached to constant within one day, which could not be predicted by the equilibrium of Ca(OH)2 dissolution. For the slag, H+ in leaching solvent was exchanged for Ca and Mg on the surface of the slag. This ion exchange reaction came to equilibrium within one day.

Heavy Metal Mobilization From Municipal Solid Waste Incineration Bottom Ash Through Metal Complexation With Organic and Inorganic Ligands
Fumitake TAKAHASHI*, Jiro ETOH* and Takayuki SIMAOKA*
*: Dept. of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University
[Fumitake TAKAHASHI] f-takahashi@doc.kyushu-u.ac.jp
Heavy metal removal from municipal solid waste incineration bottom ash using organic and inorganic ligands was investigated. Metal mobilization through the complexation with these ligands was evaluated by its leachability based on Japan leaching test 46. 0.02 mol-N/L of ammonium nitrate, sulfate, acetate, oxalate and citrate solutions with/without 0.02 mol-N/L urea were examined. In all cases, pH of the leachates were within the range from 10.4 to 11.0. Ammonium citrate promoted the leachability of Cu, Cr, Mn, P, and Fe. Especially, Fe leachability was increased more than 14 times. Ammonium nitrate accelerated only Mg leachability. Other inorganic and organic ligands showed no significant effect on metal mobilization. Under the condition that ammonium oxalate and citrate were co-existed, mobilization of Cu, Cr, Mn, P, and Fe were prohibited compared to those under the condition that only ammonium oxalate or citrate was used. Although urea itself showed no promotive effect on the leachability for most of metals, it accelerated the complexation of Cu, Cr, Mg, Mn, P and Fe with ammonium citrate or nitrate. Correlation analysis of leaching test results indicated strong relationship among Cr, Cu, P, and Mn. Fe and Mn also showed high correlation. This implies the decomposition of minerals that consisted mainly of these elements and it was supported partially by XRD analysis.

Bench-Scale Study on Improved Anaerobic Digestion of Sewage Sludge and Phosphorus Recovery
Masanobu TAKASHIMA*, Yoshihito TANAKA**
*Dept. for the Application of Nuclear Technology, Fukui University of Technology
**Technology Division, Hokukon Ltd.
This bench-scale study aimed to demonstrate the feasibility of anaerobic digestion with acidic thermal post-treatment and subsequent phosphorus removal and recovery as ammonium magnesium phosphate (MAP). For this purpose, both wastewater treatment and sludge treatment systems were constructed, and wastewater from combined sewer was treated for 105 days. The anaerobic digestion system showed excellent solids reduction, 65% of SS and 75% of VSS respectively, whereas methane production and sludge dewaterability were at usual levels due to sulfate reduction. PO4-P released from the influent sludge (T-P 287 mg/L) reached to 124 mg/L, and was recovered as MAP, which accounts for 43% recovery of phosphorus in the influent sludge. Color in the supernatant was doubled, compared to the influent sludge. Recycle load from sludge treatment to wastewater treatment, however, was insignificant with respect to color and nutrients.

Chemical composition analysis of kitchen wastes and its utilization for thermophilic L-lactate fermentation
Satoshi AKAO*, Yusuke SAKAE*, Youji IWASAKI* and Hideyuki MONGI**
*: Dept. of Management of Social Systems and Civil Engineering, Tottori University
**: Life and Environment Department, Public Parks and Natural Environment Division, Tottori Prefecture Government
[AKAO Satoshi] akao@sse.tottori-u.ac.jp
In order to utilize kitchen waste, which is widely but thinly distributed biomass, chemical composition analysis of the waste collected from local dump and its thermophilic L-lactate fermentation without sterilization was conducted. The composition analysis of 6 samples from one local dump in 2 weeks indicated that non-fibrous carbohydrate was major ingredient and accounted for 44% on average of its dry weight based on food analysis. The coefficient variation that was 15.8% of wet weight meant carbohydrate content was constant compared to other main ingredients. Semi-continuous and batch thermophilic fermentation of the waste under 55°C and pH 5.5 resulted in L-lactate production. In comparison with neutralizer between sodium hydroxide and ammonia water, efficient L-lactate production rate was provided by ammonia water. L-Lactate yield based on initial carbohydrate concentration were 0.63 and 0.69, respectively, in semi-continuous fermentation.

Effect of flooding activities in a greenhouse on the production and emission of nitrous oxide
Atsushi SADAMATSU*, Taku FUJIWARA**, Kunio OHTOSHI** and Morihiro MAEDA***
*:Graduate School of Agriculture, Kochi University
**:Agriculture Unit, Research and Education Faculty, Kochi University
***:Graduate School of Environmental Science, Okayama University
[Atsushi SADAMATSU] b07m4j02@s.kochi-u.ac.jp
The authors examined the effect of flooding activities in a greenhouse on the production and emission of nitrous oxide (N2O) through field observations. Flooding activities affected not only the groundwater quality but also the N2O gas flux strongly due to the infiltration of a large amount of N2O, NO3--N, SO42-among others, accumulated to the surface soils. Dissolved N2O and NO3--N in the groundwater decreased by denitrification in the aquifer with clay layer, and the production of N2O as an intermediate of N2 through denitrification is smaller than that during flooding activities. The cumulative amount of N2O gas flux during 1 month just after flooding was estimated to account for 93% of annual flux. This result clarifies that the influence of the flooding activity on the emission of N2O is extraordinary.

Effect of Water quality on Japanase Major River caused by Climate Change
*Graduate School of Environmental studies, Tohoku University
**Dept. of Civil and Environmental Engineering, Tohoku University
***Dept. of Urban Engineering, Tokyo University
[KAWAGOE Seiki] kawagoe@kaigan.civil.tohoku.ac.jp
This study discusses river water quality with extreme precipitation change. We tried to project the water quality change by climate change such as heavy rainfall and lengthening of no rain period, and analyzed the variation ratio of turbidity loadings such as biochemical oxygen demand and suspended solid in Japanese typical rivers according to return period of extreme precipitation. L-Q rating functions and organic pollutants sedimentation model were applied to evaluate water quality during heavy rainfall and during draught period, resepectively.
As results, we are able to point out high risk rivers, which have worse water quality after climate change in Japan. And the following detail results were obtained; 1) In the Ara and the Gouno rivers, turbidity loading increases remarkably with changing rainfall condition. 2) The turbidity loading process was clarified by draught period. 3) Turbidity loading increases from 200 to 300% in case of a heavy rainfall by climate change in Japan. 4) Turbidity loading increases about 110% in case of longer draught period caused by climate change.

Enrichment of salt-tolerant photosynthetic hydrogen fermentation bacteria and continuous hydrogen production with multiple volatile fatty acids under sun-light irradiation by solar lighting system
KAWAGOSHI Yasunori*, TAKAHASHI Hirokazu**, FUJIMOTO Aya*, and FURUKAWA Kenji*
*: Graduate School of Science & Technology, Kumamoto University
**: Engineering Division, Daiki Ataka Engineering Co., Ltd
[KAWAGOSHI Yasunori] goshi@kumamoto-u.ac.jp
Enrichment culture of salt-tolerant photosynthetic hydrogen fermentation bacteria, which produce hydrogen with multiple volatile fatty acids (VFAs) was established. The enriched biomass grew well, and produced the hydrogen with lactic acid, acetic acid and butyric acid, which are major metabolites in the wastewater of anaerobic (dark) hydrogen fermentation process. PCR-DGGE analysis revealed that the purple non-sulfur bacteria such as genus Rhodobacter and genus Rhodovulum were predominant in the enrichment biomass. The enriched biomass retained in a reactor, in which installed biomass-carrier, could produce the hydrogen continuously for experimental period (1000 h) under the combinational light irradiation of incandescent lamp and solar lighting system. However, degradation rate of each VFA was different. In both batch- and continuous-cultures, lactic acid was best consumed and acetic acid was also consumed well. On the other hand, the degradation rate of butyric acid was lower than those of other VFAs and most of it was remained in continuous culture.

Development of low cost composting toilet for developing countries
Ryusei ITO, Hiroki YAMAZAKI and Naoyuki Funamizu
Division of built environment, Graduate school of engineering, Hokkaido University
The composting toilet with low operation and production cost was developed to evaluate its operation performance and cost. It is a kind of urine diverting toilet with hand mixing device for no power requirement. As a result, weight of composting matrix increased with increasing total weight of loaded feces. The 50% of organic matter was biodegraded. The moisture content increased at initial then became stable at 55%. Organic acids were generated in the matrix at initial, but no acids were detected after 2 weeks. Some inactivation process of pathogens was required, because E-coli and coliform count was higher than conventional composting toilet with heating device. The required force for mixing increased with operation progress, but it could get small by adoption of reducer. However, adoption of reducer causes decrease of rotation number of screw and increase of force loading to the screw, relatively. The loading force from the matrix was increased with increase of weight of mixed matrix and decrease of distance between screw blade and reactor wall. The material cost in Japan was 220000 yen and over half was occupied by production of screw. In Indonesia, it was Rp. 10,000,000, (=100,000 yen) which value is over usual construction cost for toilet. The material cost of PVC for reactor wall occupied 66%.

Estimation of Probable Source for Silicate Supply and Installation Effect in the Actual Sea of Seaweed-breeding Ground Blocks Containing Waste Bamboo Charcoal from Oyster Farming Raft
Tsutomu IMAOKA* , Kazuo YAMASAKI** and Satoshi TSURUTA**
*:Dept. of Environmental Studies, Hiroshima Institute of Technology, JAPAN
**:Major in Regional Environmental Studies, Hiroshima Institute of Technology, JAPAN
[Tsutomu IMAOKA] timaoka@cc.it-hiroshima.ac.jp
The oyster of 20,000 tons per year (peeled oyster, 2005) is produced in Hiroshima Prefecture. It occupies about 60% of the domestic production, while it is estimated that the bamboo of 5,500 tons per year used as the main material of oyster farming raft have been scrapped in Hiroshima Prefecture. In this study, seaweed-breeding ground blocks containing charcoal material made from waste bamboo were estimated for probable source of silicate. In the immersion experiments of 272 days, silicate ion of 0.82 – 3.18 gSi/m2 was eluted from the bamboo charcoal-containing specimens (weight additional ratio of charcoal : 5-15%). From the result of the diving investigation, it was suggested that the adhesion of seaweed to the bamboo charcoal-containing concrete blocks was rapidly than to blocks without charcoal.

The Effectiveness of Manila Clam Maintenance Measures in Wajiro Tidal Flat of Hakata bay
FUJII Akihiko*,**, SEKINE Masahiko*,HAGIHARA Junko*, IMAI Tsuyoshi*, HIGUCHI Takaya*
*Graduate school of Science and Engineering, Yamaguchi University, Japan
*Dept. of Envirionmental Engineering, Kyushu Environmental Evaluation Assosiation, Fukuoka City, Japan
[FUJII Akihiko]fujii@keea.or.jp
We identify environmental conditions which influence growth and survival ratio of the manila clam through field and laboratory experiments, and inspect effects of the maintenance measures of the clam in Wajiro tidal flat. The hardness of the sediment is reduced by tideland cultivation and the softened sediment shows lower temperature when heated by sunlight. This shows a possibility of maintaining higher fatness of the clam during summer periods. Setting the protection net on the surface of the tideland prevents the increase of the sulfide in the sediment caused by the corruption of the Ulva, and it maintains the survival ratio of the clam. Consequently, it is shown that these measures are effective for the maintenance of manila clam resources.

The oyster reef distribution in north Ariake Bay and the environmental effect of oyster cultivation
Hiroki IYOOKA*, Hiroki OGAWA** and Tetsuya KUSUDA*
*Department of Civil Engineering, Kyushu University
**Ministry of Land, Infrastructure, Transport and Tourism
[Iyooka Hiroki]iyooka@civil.kyushu-u.ac.jp
To estimate the filtration capacity by oyster in north Ariake Bay, the oyster reef distribution was measured by using aerial photographs. The total area of the oyster reefs in north Ariake Bay has decreased to about half compared with that in 1978. It results from oyster reef removal for Nori cultivation. Based on field surveys, the oyster size distributions in two typical oyster reefs indicated that the oysters on the reefs are suffered from the ray prey in the unmanaged area. The estimation of oyster filtration indicated that the total filtration capacity via the oyster reef in north Ariake Bay decreased to 10% compared to that in 1978. Using the Box modeling method, effects of oyster cultivation on the amount of plankton was estimated. The cultivation oyster of 200 million pieces for one and half years reduces 360 tons of TN and 30 tons of TP.

Study on fish preservation efficiency of revetment blocks based on laboratory experiments
Ryoichi NAKAMURA*, Masahiko SEKINE*, Asami HASHIGUCHI**, Takaya HIGUCHI*, Tsuyoshi IMAI*
*:1Graduate school of Science and Engineering, Yamaguchi University **:2KYOKUTO GIKO CONSULTANT CO.,LTD
[Masahiko SEKINE]ms@yamaguchi-u.ac.jp
The objective of this study is to build the guide of selecting fish-friendly revetment works by establishing a quantitative evaluation method based on laboratory experiments. Preference experiments are conducted using an experimental channel which has revetment block models in both sides. As the result, when the flow velocity is 50cm/s, many fish except pike gudgeon had a tendency to shelter in blocks. Blocks function as refuses for many fish when the flow velocity is over 50 cm/s in experimental channel. We try to explain fish distribution by using preference values for velocity. Although velocity preference could partly explain the fish distribution when the flow velocity is over 50 cm/s in experimental channel. But when flow velocity is low the fish distribution is could not be explained. So It is found that the review of the preference curve and necessity of other parameters.

Distribution of extracted phosphorus from bottom sediment in Lake Inohana
Kouji TSUSHIMA*, Takanobu INOUE*, Kunihiko FUJITA*,**, Yuji KANEKO*, Shin-ichi AOKI*, Jin-hee YUK* and Toshiro YAMADA***
*:Dept. of Architecture and Civil Engineering, Toyohashi University of Technology, JAPAN
**:Hamamatsu City Office, JAPAN
***:National Institute of Public health, JAPAN
[Kouji TSUSHIMA] tsushima@tutrp.tut.ac.jp
This study was aimed to discuss the phosphorus composition of sediments in Inohana Lake, which was a branch lake of Hamana Lake. It was expected that the sediment was influenced from riverine suspended solid and influent from Hamana Lake. The riverine suspended solid samples were collected at a major influx river to Inohana Lake during a rain event and low flow period. The bottom sediment samples were gathered at ten points in the lake. Sequential phosphorus extraction techniques was applied to our all collected samples. Extracted microorganism-P much contained the sediment samples of the coastal area, and riverine suspended solid samples. It suggested that riverine particulate phosphorus sedimeted on the coastal area. Non-extractable-P was increased in the offshore points. It suggested that particulate phosphorus changed in quality in anoxic sediment. Phosphorus concentration of interstitial water in sediment was also increased in offshore anaerobic sediment.

Vertical Transport Process between Sediments and the Upper Water Column With Changing Water Pressure
Daisuke Tuchiya* ,Tetsuya Kusuda2*, Kouji Hamada**
*:Department of Urban and Environmental Engineering, Kyushu University
**:Ntional Institute for Rural Engineering
In this study, we investigated a method to strengthen water transport between the sediment and the upper water column in a bay, which is induced by ebb and flood tides as a sediment characteristics improvement technique. For using this model, it turned out that the device, an air holder, newly developed to hold air in sediments. Effect of the device was identified by laboratory experiments under varying water pressure at the same level as ebb and flood tides. The simulation model which is estimated a method is able to estimate the effect on water transport with the device. A compared result of laboratory experiments with simulated results, this model is applicable and the device is useful. Several pieces of the device were laid in the sediments at Miike muddy tidal flat in Omuta City, Fukuoka, Japan. Biological effects were identified by measuring mad flat’s oxidation-reduction potential (ORP), that is, the sediments turned aerobic

Behavior of natural estrogens in sediment: column studies and model evaluation.
RENI Desmiarti*, FUSHENG Li**, TOSHIYUKI Kawaguchi**, CHIHIRO Yoshimura***
*: Graduate School of Engineering, Gifu University, Japan.
**: River Basin Research Center, Gifu University, Japan.
***: Department of Civil Engineering, Gifu University, Japan.
[Fusheng LI] lifs@gifu-u.ac.jp
The behavior of 17b-estradiol (E2) and estrone (E1) in sediment was studied by batch experiments using sediment from a freshwater reservoir. For this, four sediment columns (two aerobic ones and two anaerobic ones) consisted of 30cm of undisturbed sediment and 60cm of overlying water collected from two sites within the reservoir were used. Moreover, through model simulations, the contribution of sorption and degradation to the behavior of E2 and E1 was estimated. When E2 was spiked, the ratio of partition coefficients of E2 and E1 in two aerobic columns, KdE2/KdE1, was determined as 9.47 and 7.83, and that in two anaerobic columns as 10 and 8.57, respectively. The degradation rate of E1 was 33-70% smaller than that of E2. When E1 was spiked into all columns, the remaining fraction in the overlying water phase and the sorbed fraction onto sediment were higher than experimental runs when E2 was spiked. The degradation rates of E2 and E1, and the partition ratio under aerobic condition were larger than those under anaerobic ones. E1 was more persistent than E2 under both aerobic and anaerobic conditions.

The origin and characteristics of sediment organic matters at three tidal flats in estuary of Nanakita River
SHIN Woo-Seok*, FUJIBAYASHI Megumu*, NOMURA Munehiro*, NAKANO Kazunori*, NISHIMURA Osamu*
*:Graduate School of Engineering, Tohoku University, JAPAN
[SHIN Woo-Seok] swoosuk@eco.civil.tohoku.ac.jp
[NOMURA Munehiro] nomu@eco.civil.tohoku.ac.jp
The purpose of this study is to clarify the origin of organic matters on sediments and the characteristics of temporal variation at an estuarine tidal flat. Silt-clay content(<63㎛), chlorophyll a, TOC, C/N ratio and the stable isotope ratio of carbon and nitrogen were measured at threetidal flats around the estuary of the Nanakita River. As a results, organic matters at Stn.A, sandy tidal flat, though terrigenous organic matters did at Stn.C, muddy tidal flat. On the other hand, Stn.B, the intermediate characteristic of Stn.A and C, was affected by particulate organic matters derived from the river water and wastewater. Furthermore, it was revealed that the volume and origin of organic matters in the sediments depended on temporal variation, and the factors were defferent from teh Stns, i.e. epiphytic algae for Stn.A, the transport of sediments from Stn.A caused byevents for Stn.B and the eventual sedimentation of organic matters originating fromterrestrial plants, respectively.

Multiroute Exposure Assessment to Haloacetic Acids
ITOH Sadahiko*, QUAN Dawei*, MUTO Teruo**, OKASHITA Ryosuke*, ECHIGO Shinya*, OHKOUCHI Yumiko*
*:Department of Urban Management, Graduate School of Engineering, Kyoto University, JAPAN
**:Nippon Steel Corporation, JAPAN
[ITOH Sadahiko] itoh@urban.env.kyoto-u.ac.jp
To establish more reasonable standard values of toxic compounds in drinking water, the information of allocation to drinking water is highly important. This study was designed to estimate allocation of haloacetic acids (HAAs) exposure to drinking water. The exposure amounts via 4 routes ( ingestion ( drinking water and food ), inhalation, transdermal exposure ), were estimated respectively based on actual concentrations of HAAs in drinking water, air, and food. The results indicated that the percentage of dietary exposure to HAAs was greater than other routes in many compounds. Therefore it was considered that dietary exposure was important in establishing standard values of HAAs in drinking water. In case of dichloroacetic acid and trichloroacetic acid, the median allocations to drinking water were lower than the current default value 20%.

Analysis of health-related incidents attributable to drinking water in Japan
YAMADA Toshiro*, AKIBA Michihiro*, ASAMI Mari*, SHIMAZAKI Dai*, KUNIKANE Shoichi**
*:Department of Water Supply Engineering, National Institute of Public Health, JAPAN
**:Institute for Environmental Science, University of Shizuoka, JAPAN
[YAMADA Toshiro] t-yamada@niph.go.jp
This study aims at demonstrating health-related incidents caused by drinking water contamination, which occurred in the past ten years of 1997 through 2006 in Japan, and analyzing their risk levels. The information used in this study is those reported to the Ministry of Health, Labour and Welfare according to the "Guidelines for the Implementation of Health Risk Management of Drinking Water". In the last ten-year period, there were 27 health-related incidents involving 2,328 cases in Japan among totally 1,018 incidents reported. The risk levels of health-related incidents were higher at small and private water supply systems compared to those at large water supply systems. Adequate management of small and private water supply system is necessary to prevent heath-related incidents caused by drinking water contamination.

Study on Analysis of Domestic Water Demand Structure in order to Forecast Water Demand
SHIMIZU Toshiyuki*, YOSHIMURA Keisuke**, YAMAKAWA Mikihito***, YAMADA Kiyoshi****
*:Graduate School of Science and Engineering, Ritsumeikan University, JAPAN
**:Nippon Water Engineering Co.,Ltd., JAPAN
***:Sakai City Waterworks and Sewerage Bureau, JAPAN
****:Research Organization of Science and Engineering, Ritsumeikan University, JAPAN
[SHIMIZU Toshiyuki] rv004986@se.ritsumei.ac.jp
[YAMADA Kiyoshi] yamada-k@se.ritsumei.ac.jp
The results of forecasting domestic water demands in long terms are important for planning water supply facilities and operation and management systems. Recently, structure water demands are being complicated due to the variation of its effecting factors. Therefore, this study was purposed to clear up the factors effecting. Besides, changes of the factors were analyzed by the results of the surveys carried out at intervals. Additionally, the actual situation of intended water usage was analyzed by measurement survey. This study reveals that household composition, lifestyle, spread of equipments, and saving water awareness are the effect factors of water consumption and usage.

Water Quality Management Characteristics in Purifcation Plants for Sustainable Maintenance
Atsuo NUMATA*,Haruhiko WATANABE**,Akira KOIZUMI**
*:Graduate School of Urban Environmental Sciences, Tokyo Metoropolitan University / Nihon Suido Consultants co., Ltd,
**:Department of Central Research Institute, Nihon Suido Consultants co., Ltd,
***: Department of Civil and Environmental Engineering, Tokyo Metoropolitan University
[NUMATA Atsuo] numata_a@nissuicon.co.jp
Waterworks in Japan approach to the times of maintenance, and are required to improve their service level of water supply. Preserving or improving of clean water quality management level is one of the important services for water users. The preservation and the improvement might be assisted by introducing useful know-how adopted in other purification plants within similar circumstance. However effective method to find the similarity is not established.
This paper deals with a method to compare a situation of water quality management in purification plants. Purification vector between raw and clean water quality is defined as a situation of water quality management, and relative purification level is discussed according to water source and treatment process. Linear discriminant function reveals statistically significant characteristics of purification plants which distinguish whether water quality is relatively improved or not in similar water sources condition. It concludes importance of mutual communication among similar types of purification plants to find useful know-how.

Efficient Water Distribution Control Plan for Sediment Removal in Pipelines using Genetic Algorithm
Takaharu KUNIZANE*, Toyono INAKAZU*, Akira KOIZUMI*, Hiroki ARIYOSHI**, Tsunehiko NISHIZAWA***
*:Graduate school of Urban Environmental Sciences,
Tokyo Metropolitan University
**:Saitama Municipal Waterworks Bureau
***:Geoplan Co.,Ltd
[Takaharu KUNIZANE] t_kunizane@bbm-k.jp
[Toyono INAKAZU] inakazu@tmu.ac.jp
The estimation method of accumulated iron rust quantities and also places in water distribution network was proposed by this paper, in order to make an efficient pipe cleaning plan. This study created genetic algorithm (GA) model combined with both the hydraulic pipe network analysis and the estimation method of accumulated iron rust mentioned above, conducted a computer simulation to calculate the amount of iron rust captured by the removal equipment.The purpose of this study is to find out the optimum operation of valves with the GA model, and maximize the captured amount of iron rust.
As the results of the simulation, it became cleared that the GA model could show the open-shut combination of valves which attained the optimum flow condition to capture the iron rust maximum.

Modeling and Simulation for Reducing Chlorine Residual Concentration in Water Distribution Systems using Artificial Neural Network
Yasuhiro ARAI*,Toyono INAKAZU*, Akira KOIZUMI*, Yousuke AKAIKE**, Chikafusa SATO**, Masaru OZAKI**
*Dept. of Civil and Environmental Engineering, Tokyo Metropolitan University
**Graduate School of Urban Environmental Siences, TMU / Tokyo Metropolitan Waterworks
[Yasuhiro ARAI] y-arai@tmu.ac.jp
The purpose of this study is to develop an estimation model for the chlorine residual concentration in water distribution systems using an artificial neural network [ANN], and analysis the decreasing residual chlorine with the developed model. This paper focuses on the water distribution reservoir and the water quality control point, and regard the pipe network which exists between those two points as a “black box”.
As the results of cross-correlation analysis and consideration of input factors with the time lag, we created the model which could clearly describe the input-output response of the complex non-linear dynamic system. This study examined some scenarios where the input data (the chlorine residual concentration at the reservoir exit) decreased by 0.05 mg/L, and conducted a simulation with the developed model. It was found that the maximum reducible concentration was 0.10 mg/L, and the reduction range from 15% to 17% was attained compared with the added quantity for the current system.

Study on Estimation Model for the Chlorine Residuals Decrease using Field Survey Data in Water Transmission Pipes
Toyono INAKAZU*, Akira KOIZUMI*, Yasuhiro ARAI*, Chikafusa SATO**, Masaru OZAKI** and Eiichi WATANABE***
*Dept. of Civil and Environmental Engineering, Tokyo Metropolitan University
**Graduate School of Urban Environmental Siences, TMU / Tokyo Metropolitan Waterworks
***Tokyo Metropolitan Waterworks
[Toyono INAKAZU] inakazu@tmu.ac.jp
[Chikafusa SATO] sato-chikafusa@waterworks.metro.tokyo.jp
One of important subjects on water quality management is to control and to reduce the chlorine residuals concentration in water transmission and distribution systems. This study purposes to evaluate the possibilities in alternatives of chlorine residuals deduction for transmission. We made a filed survey on the Tohnan main line in order to get data for modeling of the chlorine residuals decrease in big size water pipes.
First, we analyze the fluctuations in time series of the measured water quality data. Second, a kinetic model is formulated using the Arrhnius equation with TOC/C0 as a correction factor that is derived from our previous study by laboratory experiments. And this kinetic model is demonstrated to describe the chlorine residuals concentration very clearly. Finally, we examine some scenarios with a chlorine residuals reduction at the reservoir exit. It is found that the advanced water treatment allows us to get more reducible concentration compared with the current treatment.

Aunnop WONGRUENG 1, Satoshi TAKIZAWA 1, Yasuhiro MATSUI 1,
Kumiko OGUMA 1 and Suraphong WATTANACHIRA 2
1 Department of Urban Engineering, The University of Tokyo,
2 Department of Environmental Engineering / NCE-EHWM, Chiang Mai University
takizawa@env.t.u-tokyo.ac.jp; aunnop@env.t.u-tokyo.ac.jp
An ultra low pressure reverse osmosis (ULPRO) membrane process was applied to defluoridate groundwaters obtained in the Chiang Mai Basin, Thailand. The permeate water contained less than the Thai standard of 0.7 mg/L for drinking water. Although the fluoride rejection rates were high between 94.4-98.4% with all the groundwater samples, the rates went up or down during the course of filtration depending on the groundwater quality. ART-FTIR, in conjunction with saturation index, identified the foulants as SiO2 and CaCO3. The fluoride transport models were presented and verified using NaF solutions. The mass-transfer coefficient of fluoride (k) in water was estimated as 3.20 x 10-5 m/s, and the solute mass-transfer coefficient (ki) of fluoride through UTC-70U membrane as 1.06 x 10-7 m/s. Subsequently, the fluoride transport models and the mass-transfer coefficients were used to estimate fluoride concentrations at the gel-layer surface (CG) and at the membrane surface (CM). Using these values and the fluoride concentration in the bulk solution (CB), the changes of the ratios of CM/CG and CM/CB were calculated to estimate the causes of increase and decrease of fluoride rejection rates during the course of filtration experiments.