To obtain information that can be used as reference for improving the environment inside and surrounding the open channels receiving johkasou effluent, the formation and correlation of sediment bed bacterial density with water quality were evaluated with multivariate statistical analysis based on measured data for water and sediment samples collected for 8 times from 6 sites of an open channel that receives johkasou effluent in a residential area of Gifu Prefecture, Japan. Statistical analysis included principal component and factor analysis (PCA/FA), cluster analysis (CA) and correlation analysis. The PCA/FA results showed that 3 dominant factors were responsible for the water quality data structure, accounting for 85.12% of the total variance in the dataset. Hierarchical cluster analysis grouped 6 study sites into 3 statistically significant clusters, reflecting different characteristics and pollution levels of the sites. Correlation analysis revealed statistically significant relationships of the sediment bed bacterial density with BOD, total nitrogen and total phosphorus in the water of the channel receiving johkasou effluent.

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 Eukaryotic communities in two different wastewater processes, a full-scale anaerobic/aerobic activated sludge process and a pilot-scale Down-flow hanging sponge (DHS) process, was evaluated by constrcting 18S rRNA gene clone library. The clones close to the member of Opercularia was found to be a dominant eukaryote in anaerobic and aerobic activated sludges, whereas the clones affiliated to phylum Arthropoda were the most predominant in the DHS sludges. Eukaryotic communities of the activated sludges as revealed by 18S rRNA gene clone library were in agreement with published data determined by microscopic observation. On the other hand, eukaryotic communities as revealed by 18S rRNA gene clone library and microscopic observation were significantly different in the case of the DHS sluges; therefore, it was suggested that both molecular and microscopic approaches need to be conducted. The molecular approach can also reveal unidentified eukaryotic gene sequences, which might be important for understanding wastewater treatment processes.

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 Microbial community structure of a landfill leachate-treating nitrifying reactor was investigated by using molecular cloning and cultivation techniques. The most dominant phylum in the community was the Proteobacteria, which covers 65% of the clone library. In addition, candidate division TM7, OD1, and TM6 were also found as major groups. Clones close to the microorganisms capable of degrading persistent organic matters and of oxidizing ammonia and nitrite in marine environments were retrieved. Total 312 strains were isolated from agar- and gellan gum-based media, in which the isolates close to PAH degraders were obtained. Furthermore, phylogenetically novel microorganisms were also isolated.

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 Bacterivorous protozoa in the Hirose River were enriched with prey bacteria and analyzed. Additional analyses were also carried out by using spring water, groundwater, and soil extract as other sources of protozoa. Although Cupriavidus bacterium was mainly used as prey, other three bacteria that belong to genus Pseudomonas, Bacillus, and Rhodcoccus were also used. Protozoa that ingested bacteria were observed at all sampling stations along the river. In most cases, protozoa that clasified to Chrysophyceae were observed despite of prey bacterial strains. The same type of protozoa were appeared when the other environmental samples was used. These results suggest that Chrysophyceae may play an important role as predator of bacteria introduced in the natural environment.

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 A novel aluminum-based coagulant for effective virus removal was developed in the present study based on the investigation of roles of the basicity, sulfate ion and aluminum speciation in coagulation of virus. The coagulation process with the novel aluminum-based coagulant effectively removed viruses compared with other aluminum-based coagulants, and achieved apporimately 6-log removals not only in the weakly acidic and neutral pH conditions but also weakly alkaline pH conditions. In addition, Al₁₃ and Al₃₀ polymers were detecteded by electrospray ionization mass spectrometry and ²⁷Al-NMR spectrometry in the novel aluminum-based coagulant. Accordingly, Al₁₃ and Al₃₀ species are probably dominant species to control the virus removal performance, and that lead effective removals of viruses in the coagulation process with novel aluminum-based coagulant even in the weakly alkaline pH condition.

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 Algal organic matter (AOM) is one of the factors causing membrane fouling in microfiltration, and pre-chlorination can control membrane fouling by AOM. To evaluate effect of pre-chlorination on membrane fouling by AOM in ceramic membrane treatment, chemical characterization and molecular weight distribution before and after pre-chlorine treatment (1-8 mg·L^-1) were analyzed. As a result, concentrations of DOC and neutral sugar increased in all chlorination conditions, while those of protein after chlorination at 4-8 mg·L^-1 decreased. Moreover, molecular weight distribution showed that main peak shifted from 7.5 kDa to 5.2 kDa after chlorination. In microfiltration test, all chlorine treatment (1-8 mg·L^-1 ) reduced the membrane fouling. From these results, it is suggested that membrane fouling by AOM was controlled by chlorination because it denatured AOM and varied flock size.

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 Application of membrane filtration processes in large-scale water treatment facilities has expanded in recent years. In particular, they are increasingly used for surface water treatment (river and lake waters) rather than for groundwater treatment. Generally, coagulation is used to remove colloidal and suspended particles in surface water, but the effects of coagulation, which is a pre-treatment process in membrane filtration, on membrane fouling are scarcely reported. In this research, we studied the effect of coagulation as a pretreatment process of the ceramic membrane filtration system, with the focus being concentrated on investigation of the effect of Gt value of coagulation through experiments of membrane filtration after precoagulation. The results indicate that; the difference in the increase rate of transmembrane pressure depends on the Gt-value of coagulation. The optimum Gt values seem to be existent in the range of 20,000-50,000. Optimization of the Gt-value contributes to suppression of the increase rate of the transmembrane pressure, reduction of the coagulant dosage and reduction of pH control chemicals.

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 Microcystis aeruginosa is a bloom-forming cyanobacterium which causes coagulation inhibition in drinking water treatment. Previous studies on algal organic matters (AOM) of M. aeruginosa, especially on its capsule, have suggested that AOM inhibit coagulation with polyaluminum chloride by forming complex with aluminum in coagulant. In this study, organic matters having high affinity with aluminum ion were isolated from the capsule of M. aeruginosa using affinity chromatography. Molecular size fractionation analysis on isolated organic matters showed no protein peaks and one saccharides peak. This saccharides contained glucose, mannose, and an acidic saccharide. Acidic saccharides have carboxylic radicals in its molecular structure, which enhances adsorption of the saccharides to metals. These results suggested that carboxylic radicals within acidic saccharides of M. aeruginosa capsule form complexes with aluminum ion and inhibit coagulation.

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 In order to clarify the removal performances of estrogens by aquatic plants, experimental studies were conducted using four species of aquatic plants (Ceratophyllum demersum, Riccia fluitans, Spirodela polyrhiza and Limnobium laevigatum) and six enzymes (soluble peroxidase, ionicaly cell wall-bound proxidase, covalently cell wall-bound peroxidase, laccase, polyphenol peroxidase and glutathione-S-transferase) extracted from the plants. Estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) were target compounds. It was found that estrogens were efficiently removed by plants as well as by peroxidase and hydrogen peroxide inside plants. Compared with a mathematical model developed based on an assumption of mass transfer diffusion limitation, removal rates of estrogens by aquatic plants were considered to be governed by mass transfer rates of estrogens in liquid film.

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 Water quality in the multi stage vertical flow constructed wetland treating livestock wastewater was monitored and its treatment performance for two years after start-up was evaluated. Although the performance for the first year was affected by the seasonal variation of water temperature, the treatment capacity during winter season was improved significantly at second year, resulting in robust annual treatment performance of the second year. It suggested that the first year's performance of constructed wetland reflected the adapting process to the regional climate condition and the robust developped performance appeared from second year. Based on the treatment performance obtained for second year, the basic treatment unit for BOD, SS, TKN, T-N and T-P was determined as 26.2g-BOD/m²·d, 21.0g-SS/m²·d, 1.60g-TKN/m²·d, 1.55g-T-N/m²·d and 0.36g-T-P/m²·d, respectively.

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 An experiment of rice cultivation with circulated irrigation of treated municipal wastewater in a closed system simulating paddy field was conducted as a feasibility study of resorce-saving cultivation with reduced amounts of irrigation water and fertilizer. In this system, surface water always infiltrate paddy soil, is drained from culvert at the bottom and then return to the surface. Rice growth, yield and its quality such as taste and metal contents were compared between two runs, (1) circulating treated wastewater diluted by the same volume of river water and (2) circulating only river water. In Run 2, chemical fertilizers containing nitrogen, phosphorus and potassium were applied to the system according to the costumary practice. In Run 1, treated wastewater could supply the required amount of nitrogen, while deficiencies of phosphorus and potassium were covered by chemical fertilzers. The result of experiment demonstrated that there were no significant differences in rice growth, yield and its quality between two runs, indicating negligible effect of circulated irrigation of treated wastewater on rice cultivation. However, in both runs, overgrowth of rice and low score of its taste were found probably because nitrogen was not lost by runoff in the closed system.

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 Greenhouses are usually irrigated after cropping to remove accumulated salts in the topsoil. Nitrate remained in the soil is reported to be transported to groundwater due to the irrigation, resulting in high nitrate concentration in ground or surface waters. The present study evaluated the effect of a catch crop (dent corn) on leaching losses of nitrogen and phosphorus during a fallow period (catch crop cultivation, salt removal irrigation and reductive soil disinfection) in a farmer's eggplant greenhouse in Okayama, Japan, in 2010 and 2011. Nitrogen leaching was greatly reduced owing to the nitrogen uptake by the catch crop with compared to the control (p < 0.01). Differences of nitrogen losses during the fallow period between treatments were 12.2 g m^-2 in 2010 and 5.4 g m^-2 in 2011, probably due to different contents of mineral nitrogen remained in the soil after eggplant harvests. On the other hand, phosphorus leaching was not significantly different between treatments (p > 0.05). The effect of phosphorus uptake by the catch crop may be masked because of the large amount of mineral phosphorus accumulated in the soil. Our results clearly showed that catch crop growth during a fallow period reduced nitrogen leaching in the eggplant greenhouse.

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 The aim of this study was to evaluate the feasibility of rapid vermicomposting of different fresh fruit and vegetable wastes (FVWs) including banana peels, cabbage, lettuce, potato and watermelon peels using earthworm Eisenia foetida. For this, the changes of physicochemical properties, microbial profiles and earthworm biology were comprehensively evaluated after vermicomposting for 4 weeks. Compared to controls (without earthworms), vermicomposting caused reductions of the total carbon content by 42.7-52.4% and the carbon to nitrogen ratios by 46.5-61.1%, and increases of the electrical conductivity by 6.7-69.4% and the total phosphorous content by 4.0-52.0%. Vermicomposting revealed a higher microbial activity, density and diversity in end products than controls. The vermicomposting treatment for FVWs allowed a high growth rate of earthworms and an increased number of cocoons. Similar microbial community structures were observed in all vermicomposts, indicating a high degree of bio-stabilization and maturity. The results suggest that rapid vermicomposting is a feasible technology for converting fresh FVWs into valuable products and that the quality of vermicomposts is strongly associated with the properties of initial substrates.

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 A new landfill settlement model is proposed by coupling microbiological kinetics to simulate and predict municipal solid waste (MSW) landfill settlement. The model can be used to evaluate the effect of bacterial metabolisms on MSW landfill processes including settlement. The model is based on three mechanisms, namely, biodegradation of organic carbon mass, stress variation and moisture removal from waste particles (IMR) and pore spaces. Model simulation indicates that the contribution from biodegradation is small within a short period of simulation time. The landfill settlement has been dominated with water removal induced settlement where landfilling solid waste has high percentage of biodegradables and moisture content. To examine and simulate MSW landfill settlement process, a lab scale column experiment was carried out with synthetic MSW. The observed MSW landfill settlement in column experiment was used to verify the proposed model. The simulation and experiments suggested that effect of water removal will influence primary stage of settlement and this process will be introduced as a new mechanism for landfill settlement modelling. However, a careful demarcation between mechanically induced settlement and effect of internal moisture present in waste particles has to be explained by considering absorptive properties of waste particles, level of compaction and age of the waste.

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 Understanding the effects of environmental conditions (e.g. temperature and pH value) on organic carbon dissolution behavior is very important for quantifying the biodegradation of municipal solid waste. However, the dissolving of organic carbon from solid waste has not been sufficiently described. In this paper, the dynamic of organic carbon dissolution under different temperature and pH value conditions are analyzed by both experiment data and model simulation. The results revealed that lower leaching pH values are favor for dissolving organic carbon especially rapidly dissolution fraction of the solid samples. Under high temperature extraction condition, the dissolution rate of rapidly dissolution fraction was also improved and the amounts of biodegradable products exceed low temperature extraction amount. The dissolving rates of organic carbon were in the order of 0.045-0.22 m³/kg/h for all leaching conditions. The labile fractions of water extractable organic carbon were ranged from 3.5% to 20.3%. Therefore, the water extractable organic carbon extracted from MSW consists of substantial amount of stable fraction, indicating that anaerobic bioremediation of old landfill site is ineffective.

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 This paper presents the degradation ability of selected strains on poly butylene succinate-co-adipate (PBSA) in culture medium and compost. Thirty four strains of PBSA degrading bacteria were isolated from compost and activated sludge, and six of them were used as inocula for the experiments to investigate PBSA degradation ability in compost. The results revealed that bacteria inoculation could accelerate the PBSA degradation. Two strains (Acinetobacter sp. Strain.S49 and Acinetobacter sp. Strain.S6) showed high ability of degrading PBSA in compost, whereas the other four strains showed minor effects. Based on the findings in this work, the importance to investigate the ability of PBSA degrading bacteria not only using pure culture medium but also using multi-microbial community such as compost was indicated.

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 In Japan, we have been severely damaged by natural disasters. Recently, the disasters caused by climate change are also expected. In order to take effective and efficient measures such as broad disaster prevention plans and business continuity plans against such natural disasters, the authors developed 'Water Supply Hazard Map' which can visualize the information of the water supply utilities and their risks, by which we can estimate impacts of disasters in each basin widely and integratedly. Furthermore, the developed 'Water Supply Hazard Map' was applied to Kino river basin and Oyodo river basin. As a result, each impact of the municipalities on water supply utilities such as water intake points, water treatment plants, and affected population could be quantitavely assessed using the indicators such as the seismic intensity levels of the earthquake and the inundation levels of tsunami flood. In addition, differences of the two basins were estimated and it turned out that the affected population in Oyodo river basin was larger and more concentrated in a few specific cities than those in Kino river basin.

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 The corrosion of bronze joints - used with stainless steel pipes and many of which remaining in the ground - has been one of the causes of water leakage. Therefore this paper evaluates the progress of galvanic corrosion between stainless steel pipes and bronze joints-equipped pipe to soil potential. First, we measured spontaneous potential of four metals used for service pipes and distribution pipes in six kinds of soil at a laboratory. The result showed that each spontaneous potential varied considerably with passage of time, then the order of the potentials was approximately SUS316 > bronze > lead > ductile cast iron, after four hundred days. In addition, we measured pipe to soil potentials and maximum corrosion depths of 318 pieces of stainless steel service pipes dug mostly in Tokyo area. The result showed that the proportion of corroded bronze joints and the maximum corrosion depth increases with an increase in pipe to soil potential.

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 One of important subjects on water quality management is to control and to reduce the chlorine residuals concentration in water transmission and distribution systems. The purpose of this study is to devise an integrated simulation model for the fluctuation of chlorine residuals concentration in the distribution system. We used a field survey data in order to device the useable chlorine residuals decrease model in actual facilities.
 First, we developed an integrated simulation model to estimate the chlorine residuals at the distribution reservoir exit using 5 explanatory variable. Secondly, we devised estimation model for the chlorine residuals in distribution area to apply the GIS for tap water using the chlorine residuals at the water supply station exit caluculated on the above-mentioned model as a input value. Finally, we evaluated the reduction of chlorine residuals in the sevice pipe branched from the distribution pipe compared the chlorine residuals between the survey data and estimated value applied our model.

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 The difference of the unit price of water used has been focused. Since water pricing has some effects on the local economic development, it is important to set an appropriate water price considering the amount of water used in different type of industries. In this study, a statistical approach has been performed to examine the relationship between unit price of water use and area characteristics such as the rate of manufacturing business amount, immigration of laborers and management of sewerage system. In addition, a local economic model that includes the manufacturing industries and households has constructed. In terms of economic welfare, it is desirable to reduce unit of water price in the local area which is depended on the manufacturing industries.

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 Newly developed simultaneous extraction and quantitation methods for oseltamivir phosphate (OP), oseltamivir carboxylate (OC) and zanamivir hydrate (ZH) were used to monitor the drugs in upstream section of Neya River water in Osaka during the last three consecutive influenza seasons (2009/2010, 2010/2011 and 2011/2012). High concentrations of the drugs (particularly for OC) were observed in the water in the three seasons. Influenza index values, defined as average number of reported influenza cases per hospital within the coverage area during a week, were also calculated. Strong direct correlations between the index values and measured drug concentrations in the water (particularly for OC) indicated that influenza index values may be used in estimating concentrations of anti-influenza drugs in receiving waters in seasonal influenza. An ecological risk assessment indicated that the antiviral drugs at concentrations observed in Neya River water may not have negative impacts to the environment except in pandemic influenza cases. These findings can be a useful reference for other similar cases and for further investigations.

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 In order to mitigate the pollution of the river water attributed to the urban wastewater discharged from the middle part of Yodo river basin, bypass channel system with river water treatment facilities was equipped at Yodo River basin. In this study, attenuation of 53 pharmaceuticals and personal care product (PPCPs) were clarified both in the Yodo river bypass channel system and the river by the field survey and these two were compared considering several scenarios for the system operation in order to evaluate the utility of the Yodo river bypass channel system. As the result, attenuation of PPCPs in the Yodo river bypass channel system was suggested to be comparable to that in the river line or smaller than that in the case of expansion of inflow and area covered by the channel, due to photolysis by sunlight and adsorption to the sediment in the river line.

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 In this study, we investigated i) relationship between habitat type and qualitative and quantitative characteristics of deposited sediment and (ii) the characteristics of deposited sediment and respiration activity of the sediment as determined by oxygen consumption rate in a floodplain of the Tagliamento River. Field observation indicated that C/N ratio and size of sediment increased in upstream-connected backwater and main stream, while habitats with high abundance of trees provided high density of fine particulate sediment (FPS) as well as high content of fine particulate organic matter (FPOM). We confirmed that the FPS density and FPOM content have strong correlation with dissolved oxygen consumption rate, suggesting that the oxygen consumption rate in water column is influenced by habitat type and quality and quantity of sediments.

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 Various chemical substances are used in our industrial, agricultural, and daily activities, and are continuenly discharged into the environment. Several toxic chemical substances have been detected from wastewater and surface water, and their additive or synergistic effects have become growing concerns. Thus, there is an apparent limitation in the risk assessment and management based on the individual chemical assays. In the present study, 28 samples were collected at first class rivers in Japan between October 2011 and April 2012. We conducted the short term chronic toxicity test using fish, daphnia and algae of the USEPA's whole effluent toxicity (WET) method to evaluated the toxic effects of the river water samples, and investigated distribution and trend of the toxicity all over Japan. As results, the significant growth inhibition for green algae (Pseudokirchnerella subcapitata) was found from three samples. The significant mortality and reproductive effects were found for Ceriodaphnia dubia from eight samples. The significant inhibition of hatching and survival was found for zebra fish (Danio rerio) from four samples.

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 The rubble fishway works are attracted attention from the viewpoint of restoration of river environment because it make migration path of various aquatic creatures possible by creating various flow field and create satisfactry river landscape and adopt landscape of periphery. But, design technique of the rubble fishway works which used a native rock is not established and there are many problems. So, in this research, We installed the rubble bed protection work concrete block imitated gravel materials of natural river with grade 1/10 and 1/20, and We did hydraulic model experiment and the going up experiment that used Tribolodon hakonesis, Gnathopogon elongatus, Eriocheir japonica etc. As a result I confirmed going up of all genus of a creature used for experiment with longitudinal slope 1/10 that were severe condition as the rubble fishway. And We suggested the hydrology equation that could do simply examination about going up of fishes by observation data of flow velocity and water depth with hydraulic model experiment. Further I confirmed energy dissipating effect as low pitch falling works because roughness modules of an artificial stone became big value.

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 Swimming behavior of a school of fish in running water has not been investigated. Recently, Onitsuka et al. investigated on the swimming behavior of isolated or a couple of fish in running water. In this study, the swimming behavior of a school of ayu, consinting of 5 fishes, in running water was investigated. It was found that the streamwise length of a school increases and the spanwise length of that decreases with an increase of the flow velocity and also that the swimming speed in the streamwise direction increases with an increase of the flow velocity. The turning angle of swimming trajectory decreases with an increase of the flow velocity. The individual distance becomes larger when the velocity is increased.

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 Fishways have been constructed to facilitate migration of fish past dams, waterfalls and rapids. It is necessary to understand appropriate geometrical shape of the fishway. The most of fishway in Japan is pool-and-weir fishway. In order to get high value of migration rate, it is necessary to set up pool length is larger than width of pool. However there is little information of effects of the form of the pool on migration rate from other than a rectangle. In this study, the form of the pool in a pool-and-weir fishway was changed 3 patterns and the discharge in each form was changed. It was found that the form of pool affects on the migration route.

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 Through a soil survey, the authors collected soil samples from different strata at locations where landslip had occurred in the upstream area of a dam reservoir suffering from long-term turbidity. And soil specimens that might be responsible for accelerating the turbidity were obtained from the soil samples, using a simple suspension method. The soil specimens were categorized into four risk levels, indicating their degree of turbidity. Further, we prepared a detailed geological block diagram, which specifies different geological structures based on metamorphic grades. As a result, it was found that there was a significant correlation between the distribution of geological structure and the locations where high-risk-level soil samples were collected. This information is useful for determination of the distribution of soil structure at specific locations where there is soil causing turbidity, contributing to effective countermeasures for long-term turbidity in dam reservoirs.

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 Following periods of heavy rain from severe storms and typhoons, water with high turbidity and high levels of suspended matter flows into reservoirs from watershed areas. High turbidity levels may continue to persist for some time. Furthermore, when reservoir water turns cloudy, it can disrupt water purification system and resources for an extended period. This paper, as basic research, measures the movement of high turbidity water through Ogouchi Reservoir in order to control water quality by releasing high turbidity water during heavy rains. We compare suspended solids between normal conditions and periods of high turbidity, and this analysis of suspended solids that flow into the reservoir during rainfall forms the basis of our data. We discuss the causes of turbidity and consider its influence. As a result, we show that the high turbidity in the reservoir is due mainly to clay particles with the size of less than 5μm. Moreover, we confirmed that the suspended solids contain certain amount of phosphorus which is consisted mainly of phosphate ion.

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 We estimated seasonal changes in the dissolved silicate (DSi) in Hyugami reservoir in Fukuoka prefecture by field surveys, and also calculated trap values. DSi concentrations in surface water decreased in periods of diatom blooms from spring through autumn, while the concentrations in bottom water increased from one to three months after the blooms. In winter, the breakdown of thermal stratification led to homogenized DSi values throughout the whole water. These seasonal changes altered concentrations in the outflow water as well. From spring through autumn, concentrations in outflow tended to be lower compared to those of the inflow. Conversely, the concentration of outflow in winter tended to be higher than that of the inflow. This regression from bottom water in winter reduced DSi traps through the year. Material balance analysis revealed that the DSi trap values in Hyugami reservoir in FY2010 and FY2011 were -2.0% and 10.9%, respectively. We estimated that the DSi trap for the full-year was 5.2%.

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 Bivalve is one of the representative animal of tidal flat. The objective of this study is to clarify the effect of food source affecting growth of bivalve (Nuttallia olivacea). Carbon stable istope (SI) , composition of fatty acid (FA) and fatty acid specific stable carbon isotope (FA-SI) . In the result, SI of the bulk sample indicated main food sources roughly. However the composition of FA revealed that EPA and DHA were useful nutrients for bivalve. Furthermore, FA-SI showed terrestrial EPA and DHA are more important food source. Therefore, it was considered FA-SI analysis was useful to clarify food web of various ecosystem.

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 Waterborne and oyster-borne diseases are great concerns in Ishinomaki coastal area because a wastewater treatment plant was unable to utilize activated sludge process after the tsunami. In this study, we detected several kinds of enteric viruses, which are one of the most probable causes of the infection, and microbial indicators in quantitative manner. Two virus concentration methods, i.e., a novel large volume method and a conventional small volume method, were performed for a comparison purpose. Efficiencies in each of nucleic acid extraction and RT-qPCR were evaluated by internal controls. Aichi viruses and GII- and GIII-F-specific RNA phages were dominantly detected. GI- and GII-noroviruses and sapoviruses, causative agents of viral gastroenteritis, were also found. Viruses and indicators seemed to diffuse from wastewater treatment plant in both horizontal and vertical directions. The large volume virus concentration method gave higher positive ratio than the small volume method. However, the virus detection was more likely to be affected by RT-PCR inhibition. High molecular weight (>10 kDa) organic compounds which absorb 254 nm ultraviolet were assumed to be causes of the inhibition. We demonstrated distributions of pathogenic viruses in Ishinomaki coastal area as well as need for methods to relieve RT-PCR inhibition efficiently.

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 The purpose of this research is to figure out the transport mechanism of the swimming larva in Yamaguchi bay. The method of this research is the numerical analysis using three-dimensional fluid dynamics model considering drying out and flooding of the tidal flat, wind stress, and water density, which ware not considered in the previous studies. In this calculation, it was found that the flow changes by considering these factors and that the larva is exchanged between the Minami tidal flat and east part of Naka tidal flat. This result indicates the importance of considering the wind stress and density difference in the numerical analysis.

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 This study attempted high-rate thermophilic anaerobic digestion of sewage sludge by applying thermal pretreatment of waste activated sludge (170°C and 1hr) and trace metal addition (0.49 mg-Ni/L and 0.54 mg-Co/L). For this purpose, thermophilic anaerobic digesters were maintained at a short HRT of 10 days throughout this study. The thermal pretreatment not only increased VS and VSS destruction by 6% and 9%, respectively, but also improved dewaterability of digested sludge drastically. The trace metal addition showed negligible effect on the overall performance, except for the reduced VFA concentrations in the digested sludge with a statistical significance. DGT analyses implied that the majority of soluble Ni and a portion of soluble Co are present in a bioavailable form. Furthermore, the Co content in the influent sewage sludge was suspected to be insufficient nutritionally. Microbial analyses based on PCR-DGGE detected the archaea, Methanosarcina sp. and Methanosarcina thermophila, in the digested sludge.

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 In this study, the effectiveness of sewage sludge incineration system with waste heat generator were estimated focused on the energy characteristics of sewage sludge. Specifically, the two system scales of conventional incineration, incineration system with waste heat generator after the advanced centrifugal dehydrator, and various sewage sludge fuelising were compared and evaluated from viewpoints of greenhouse gas emissions and ulitity costs by calculation.
 As a result, utility cost of incineration system with waste heat generator was lowest and 30% lower than that of conventional incineration system. Greenhouse gas emission from incineration system with waste heat generator were higher than that from sewage sludge fuelising systems. However it was lowest only in sewage treatment facilities and over 90% lower than that from conventional incineration system. The effectiveness of sewage sludge incineration system with waste heat generator were suggested.

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 Co-digestion of sewage sludge and other organic wastes is a promising technology, but performance of the co-digestion might be different in different sewage treatment plants. Characteristics of sewage sludge were analyzed and its anaerobic digestion performance was evaluated by batch experiments in eight sewage treatment plants all over Japan. The methan conversion ratio of the mixed sludge was around 0.6. The TCOD_Cr/VS and PCOD_Cr/VSS ratios of the mixed sludge and the digested sludge were around 1.7. The effect of co-digestion with synthetic food waste was similar in different plants. These results can be used to estimate co-digestion performances in different sewage treatment plants.

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 Main objective of this study was to examine the behavior of perfluorooctanoic acid (PFOA) during biological treatment process at WWTP by doing three laboratory-scale studies including (a) a batch adsorption experiment of PFOA onto activated sludge, (b) a semi-batch experiment to treat wastewater containing PFOA with activated sludge, and (c) a batch biodegradation experiment of 1H, 1H, 2H, 2H-Perfluoro-1-decanol (8:2 FTOH) which is one of the PFOA precursors. Fresh and acclimated activated sludge were used in this study. As a result; 1) PFOA loading with synthetic wastewater into semi-batch reactor resulted in increased amount of PFOA attatched with activated sludge in the reactor. 2) At the end of the experiment with PFOA loading with real wastewater, the sum of the total amount of PFOA found in effluent and in the reactor was as much as 198% of the sum of the total amount in influent. 3) On the 8th day of 8:2 FTOH biodegradation experiment, PFOA was identified as much as 2.9% of the orginal molar concentration.

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 Perfluorinated compounds (PFCs) are synthetic chemical which is persistent, bio-accumulative and suspected to be toxic. Municipal wastewater treatment plants (MWWTPs) have been identified as sources of PFCs contamination in water environment. This study focused on the contamination of eleven PFCs in samples collected from seven MWWTPs and in Bangkok, Thailand. The samples were collected from major of wastewater treatment processes in order to understand the behavior of PFCs in MWWTPs. All MWWTPs used activated sludge process to treat wastewater. The result showed that Chong Nonsi MWWTPs had the highest of PFCs concentration in final effluent (63.6 ng/L). Perfluorootane sulfonate (PFOS) and perfluorootanoic acid (PFOA) were predominant PFCs detected in final effluents than other PFCs. Final effluents had higher PFCs concentration than influents of the MWWTP which indicated that conventional wastewater treatment process using activated sludge was not effective to remove PFCs. Long carbon-chain PFCs tended to adsorb on particulate phase more than short carbon-chain ones. Comparing to other countries, the effluent concentration levels of PFOS and PFOA in Thailand were lower than those in Denmark, Taiwan and Singapore. However, several PFCs were detected in MWWTPs, suggesting municipal wastewater is one of the sources of PFCs contamination in the environment.

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 The objectives of this study were to determine the occurrence and fate of N-nitrosamines in wastewater treatment plants (WWTPs: X and Y), and to evaluate formation potential of N-nitrosamines on chlorination (FP_Cl) and efficiency of FP_Cl reduction by biological treatment. We also investigated the residual FP_Cl in the final discharge. As the results, the concentrations of N-nitrosamines in the influent were ranged from 3 to 237 ng/L. The removal efficiencies of N-nitrosamines were ranged from 28 to 99% by biological treatment. The production rates of N-nitrosamines were ranged from 14 to 66% by disinfection. The N-nitrosamines FP_Cl in WWTP X were higher than those in WWTP Y, and the efficiencies of N-nitrosamines FP_Cl reduction by biological treatment were ranged from 2 to 94% in WWTPs X and Y. The concentrations of residual N-nitrosamines FP_Cl were ranged from 2 to 848 ng/L in the both WWTPs. Thus, N-nitrosamines could be produced in water purification or reclamation plants using discharge from WWTPs.

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 Ozone-added activated sludge process is one of the modified processes for reduction of excess sludge production. Although ozone-added activated sludge system was originally developed in order to reduce excess sludge production, it is expected that its direct ozonation to activated sludge can also remove some biorefractory compounds by chemical oxidation, and the treatment efficiency and stability can be increased as results. In this study, phenol was used as a biorefractory compound in wastewaters and behaviors of EDCs at sludge ozonation were also investigated in order to evaluate several functions of ozone-added activated sludge process. The treatment characteristics were investigated with lab scale experimental setups. It is made clear that direct ozonation to activated sludge within a range of 15 mgO₃/gSS does not inhibit biological activities and biorefractory compound(phenol) is promptly removed chemically. On the other hand, the experimental case without ozonation can not remove phenol quickly and biological activity is inhibited by existence of phenol. These results suggest that the system can treat wastewaters which contain biorefractory compounds effectively and stably besides both bulking control and low excess sludge production.

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 Plasmid-mediated bioaugmentation was demonstrated using sequencing batch reactors (SBRs) for enhancing 2,4-dichlorophenoxyacetic acid (2,4-D) removal by introducing Cupriavidus necator JMP134 and Escherichia coli HB101 harboring 2,4-D-degrading plasmid pJP4. C. necator JMP134 (pJP4) can mineralize and grow on 2,4-D, while E. coli HB101 (pJP4) cannot grow on 2,4-D because it lacks the chromosomal genes to degrade the intermediates. The SBR introduced with C. necator JMP134(pJP4) showed 100% removal against 200 mg/l of 2,4-D just after its introduction, after which 2,4-D removal dropped below 12% on day 7 with decline of the introduced strain. The SBR introduced with E. coli HB101(pJP4) showed low 2,4-D removal, i.e., below 20%, until day 7. Transconjugant strains isolated on day 7 from both SBRs belonged to Pseudomonas plecoglossicida and could not grow on 2,4-D. Both SBRs started removing 2,4-D after day 16, with the appearance of 2,4-D-degrading transconjugants belonging to Burkholderia sacchari.

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 In this study, a single chamber Microbial Fuel Cell (MFC) was applied for the treatment of synthetic wastewater with the aim of evaluations of short-chain fatty acids degradation (propionate, butyrate) and electricity generation. As the result, process performance of short-chain fatty acids (containing propionate, butyrate and valerate) fed MFC was obtained COD removal 88% and coulombic efficiency 59.9% at external resistor of 100 Ω. This performance was almost equivalent to acetate fed MFC. Furthermore, the influence of external resistance value to the performance of the MFC was investigated. The changes in value of external resistance showed strong influence on organic removal in the short-chain fatty acids fed MFC than the acetate fed MFC. Organic removal rate was tended to increase at low external resistance in the short-chain fatty acids fed MFC. Biodegradation rate of propionate or n-butyrate was observed different trend at external resistance value. At high value external resistance, degradation of n-butyrate was promoted. On the other hand, propionate was obtained high biodegradation rate at low value external resistance.

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 In this study we evaluated the performance of the full-scale settling tank when the influent temperature rose and the effect of a new baffle to minimalize the deterioration using CFD calculation. A temperature rising of 5 °C inverted the influent and effluent density and make a temperature stratification. The temperature stratification lead to increase of effluent SS concentration more than twice during 4.5 times of HRT. The baffle prevented the warm plume from reaching the outlet weir directly and broke the temperature stratification. Under constant temperature, not rising up, the effluent SS concentration from the baffled settling tank was a little larger, but when the temperature rose up, the effluent SS concentration from the baffled settling tank was much smaller and temporary SS increase continued much shorter.

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 The removal of boron by the hydroxyapatite formation reaction using Ca(OH)₂ and (NH₄)₂HPO₄ in room temperature has been reported. This method's the reaction time was shortened to 1/10 of that of the conventional technique. Reaction temperature, reagent's grain size and reagent including inpurities for this method was investigated. This method was also tested in two real wastewater samples (grass industrial wastewater and final disposal site wastewater). The amount of residual boron in two real wastewater samples was also reduced under boron effluent standard by using this method. In this method, removal of boron was concerned with purty of Ca(OH)₂ reagent and coexisting ions in wastewater.

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 In this study, in order to evaluate the effect of COD loading rate on UASB reactor treating synthetic wastewater containing sulfate, acetate acid and ethanol, a continuous experiment was operated by shortening HRT stepwise from 48 to 2 h. The experiment results indicated that at COD loading rate 12.3 g-COD/L/d, the COD removal rate was maintained above 86.5%. With HRT in the range of 3-12 h, 47.5%-54.4% of the influent COD was converted into biogas methane, and 21.4%-28.0% was converted into sulfide. After this continuous operation of the UASB reactor, granular sludge with an average particle size of 1.8 mm and sedimentation velocity of 96.5 m/h was gained. In addition, the anaerobic degradation pathway of ethanol under sulfate-rich condition was investigated according to the test result of methane-producing activity (MPA) and sulfate-reducing activity (SRA).

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 A Submerged Anaerobic Membrane Bioreactor (SAMBR) combining anaerobic digestion and membrane separation has been attracting attention recently, because it may recovery methane and reduces sludge production. In this study, a lab-scale SAMBR treating soluble synthetic wastewater were continuously operated for 110 days at a room temperature of 25 °C to investigate the effect of hydraulic retention time (HRT) on the treatment performance. The HRT was changed from 48 to 6 hours by 4 steps. At a HRT of 12 hours, COD and BOD removal efficiencies were 94%, 96%, respectively. As a result, 72% of input COD was converted to methane, and sludge production was 0.1 gVSS/gCOD_rem, which is about 1/3 of that for activated sludge process. Continuous operation was successful for over 70 days without membrane cleaning using backwash and chemical.

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 The fate of pharmaceuticals and personal care products (PPCPs) in soil aquifer treatment (SAT) was investigated for the introduction of a water reuse system with SAT in Japan. A series of batch experiments simulating short-term SAT with decomposed granite soil was conducted to evaluate the biodegradability and sorption characteristics on nine PPCPs, and to search microbial transformation products produced through SAT. The degradability of PPCPs greatly varied among the tested PPCPs. Thus, SAT should be combined with WWTP and WTP effectively. In addition, several transformation products were found and their backbone structures were similar to those of original compounds. The risk of these transformation products is yet to be determined, but more serious attention should be paid to the fact that unknown compounds will remain even after SAT and may pose health risks when reused.

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 The removal characteristics of coliform bacteria by certified structure type small-scale Johkasou were studied. The results showed that among 25units of investigated Johkasou 24 units could meet the effluent quality standard of coliform bacteria count under 3,000cfu/mL before chlorination, and all units could remove coliform bacteria count less than 1,000cfu/mL after chlorination. However, about 200cfu/mL of coliform bacteria count was detected, in spite of having detected residual chlorine in effluent over 2mg/L. Coliform bacteria count in effluent before chlorination was negatively correlated with nitrifying ratio and positively correlated with SS, respectively. Therefore it was considered that highly removal of coliform bacteria was possible by advanced Johkasou which could remove nitrogen and SS.

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 This study investigated the relationship between a apatite solubility and an amount and mechanisms of lead sorption using apatite samples, which have different cristalinities and impurities contents, to estimate the amount of the lead sorption onto the apatite from phosphorus extraction by a citric acid. The amount of the lead sorption increased linely with increases in an amount of calcium dissoleved from the apatite. It was considered that the sorption mechanism of lead were both precipitation of Pb-phosphate minerals like pyromorphite and surface complexations onto the apatite. The amounts of the lead sorption by surface complexations were almost equivalent even if the solubility of apatites was different, indicating that the increases in the solubility would only induce to the precipitation to increase the lead sorption. It was also confirmed that the maximum amount of lead sorption can be predicted from phosphorus extraction by 0.01M citric acid.

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 Thermal treatment of pig manure followed by batch and continuous methane fermentation was conducted in order to evaluate its effect on fermentation performance. Up to 200°C of thermal treatment, solubilization of VSS proceeded, but transformation of dissolved TOC with high molecule count into VFA was minimal. The high temperature led to retardation of initial gas generation and low gas generation rate. At 250°C, no gas generation occurred. At 150°C, methane generation per input VS with thermal treatment was 1.2 times greater than that without thermal treatment. The thermal treatment of standard pig manure was disadvantageous to net energy recovery. However, it was estimated that thermal treatment of manure with SS concentration of greater than 2.3 times the SS of standard manure increased net energy recovery over that without thermal treatment.

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