In this study, DHS (Down-flow Hanging Sponge) reactor was used for partial nitrification of ammonium rich actual wastewater. To prevent pH decrease with nitrification, step-feeding was applied to DHS reactor and evaluated its effect on partial nitrification. The conventional one point feeding, 2 step feeding, and 4 step feeding were applied under constant nitrogen volumetric loading. Under the one point and 2 point feeding condition, about 40% of ammonium was oxidized and effluent pH was decreased to around 6.0. But for 4 step feeding condition, the pH was maintained around 7.5 despite the about 50% of ammonium was oxidized. Retained sludge of the DHS reactor had 26~49 mg-N/g-VSS/day of denitrification activity on day 516. From the profile of denitrification activity, step-feeding could be enhance the denitrification not only prevention of the pH decrease.

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 The possibility of AAFEB-Anammox reactor applied for high nitrogen loading rate is investigated in a continuous experiment operated at 35°C. The nitrogen loading rate (NLR) was changed periodically to study the performance at each condition. The removal efficiency, specific Anammox activity (SAA) and sludge characteristics were investigated. As a result, at NLR as high as 40gN/L/d, the TN removal efficiency reached 87.97 ± 1.00%. Maximum specific Anammox activity (MSAA) under condition of NLR 30gN/L/d showed 0.68 ± 0.07gN/gVSS/d. The Anammox granule formed in the reactor showed very good settleability with a setting velocity over 263.1 ± 26.9m/h. It was revealed that AAFEB-Anammox reactor is suitable for high nitrogen loading rate.

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 As completely autotrophic nitrogen removal process, one-stage anammox has attracted attention world-wide. A nitrogen removal process via one-stage anammox with suspended biomass carrier was operated in CSTR reactor. On the basis of surpassing the activity of NOB, the start-up of the one-stage anammox via the symbiosis of AOB and Anammox bacteria could be achieved in about 80 days. Under the condition of 25°C, the packing ratio of carriers as 30%, NLR as 0.5kgN/m³/d , the average and maximum nitrogen removal efficiencies were 69.6%, 81.1%. In addition, the nitrogen removal efficiency maintained as 69.6% averagely even though the NLR was doubled. The results of activity experiment revealed that on one hand AOB exist in both the surface of carriers and suspended sludge; on the other hand, the vast majority of Anammox bacteria grew in the surface of carriers. Furtherly, the symbiosis of AOB and Anammox bacteria in carriers was confirmed, which may deduce that carrier provided huge space for the growth of both AOB and Anxmmox. At last, the nitrogen removal potential could be deduced that the maximum nitrogen removal capacity was 2.56kgNH4⁺-N/m³/d.

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 Porous concrete has been used for promotion of self-purification at the river and the waterway as an attached growth medium for microorganisms. Recently, porous concrete with zeolite is developed. Zeolite has cation exchange ability and adsorption function which can increase water purification ability. However, the effects of porous concrete with zeolite is not understood in detail.
 In this study, ammonia removal and biological nitrification using porous concrete with zeolite were focused. Effects of porous concrete characteristics such as the porosity, the mixing rate of the zeolite, and the zeolite type(supported cation type) on ammonia adsorption, attached growth of microorganisms including nitrifying bacteria, and ammonium nitrogen removal were investigated.
 It was shown that porous surface can increase both specific surface area and microbial amount attaching to the media, which resulted in the increase of ammonia removal rate up to around double and the removal ability. It was also understood that the ammonia adsorption by zeolite showed similar positive effect for nitrogen removal to biological nitrification. Adsorption and biological reaction can happen at the same time, which suggests the multiple function for ammonia removal by the porous concrete with zeolite. It is suggested that zeolite type can affect on the nitrification, whereas there was not clear relationship between nitrifying activity and the amount of nitrifying microorganisms.

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 We evaluated the behavior of radioactive Cs deposited by the accident of Fukushima Daiichi Nuclear Power Plant in the Uda River locating in the coastal region of Fukushima prefecture during the super heavy rain event (Typhoon Etau). The estimated total runoff volumes of Cs-137 from small forest catchment, dam lake, and the entire river catchment during the event were 1.4 to 5.3 times greater than the annual total runoff volumes in 2014, respectively. However, the sizes of Cs-137 runoff fell much below those of SS runoff from Matsugabou dam lake and the entire Uda River basin due to the decrease in concentrations of Cs-137 associated with SS by possible effect of decontamination operation in the catchments.

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 Main objective of this study was to study on the behavior of perfluorinated carboxylates (PFCAs) and their formation potentilas (9 PFCA-FPs) during river transport where the main water source is treated wastewater. 9 PFCAs, 14 precursors and 9 PFCA-FPs were analyzed from wastewater (n=2), river water (n=35), and river sediment (n=7). A s a result, PFCA-FPs were remained in the treated wastewater and discharged to river. Formation of PFOA and PFHxA during river transport was suggested from the result of their loading increase and decrease of the corresponding formation potentials. Attempt on MRM analysis by LC-MS/MS for unknown fluorinated compounds resulted in detection of peaks which matches with the MRM condition of 5:2Ketone and 5:3FTCA and its occurrence in particulate-phase of river water and sediment indicated that 5:3FTCA was accumulated in the sediments in the surveyed river.

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 In order to grasp horizontal distribution characteristics of port and harbor sediments, we analyzed statistical characteristics of sediment quality data collected in Nagoya Port. Total 35 sediment quality items were categorized into three groups; Group 1 is mainly composed of the sediment physical property including organic compounds, Group 2 is composed of heavy metals, and the Group 3 contains PAHs. PAHs were further classified into four sub-groups, following their special distribution patterns. Statistical characteristics of their skewness and sharpness were compared their logK_ow. Relation of the distribution pattern and the physico-chemical characteristics of PAHs as well as estuarine gravity circulation currents were discussed.

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 In order to develop a simple risk evaluation method for SO₂ erupted from Mt. Aso in Kyushu district, west Japan, relationships between SO₂ concentration variations observed at a point 20km east from the crater of the mount and some meteorological observation data were examined. By using cluster analysis, days when observed SO₂ concentration were relatively high, were selected from the target period and the meteorological data of the days were analyzed. Some typical meteorological patterns which can cause high SO₂ concentrations were clarified.

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 This study aimed to compare the removal rates of precursors of disinfection byproducts (DBPs) by ferrihydrite (FH) and powdered activated carbon (PAC) in the hybrid adsorption-microfiltration (MF) processes. The formation potentials of trihalomethanes and haloacetonitriles (DBPFPs) and characteristics of dissolved organic matter (DOM) from drinking water sources having different contents of aromatic DOM and bromide, were evaluated before and after the FH+MF or PAC+MF treatments. It was found that the DOM characteristics influenced significantly on their removal rates; namely, the FH+MF process lowered DBPFP in waters containing aromatic DOM by mainly removing precursors of chlorinated DBPs, whereas brominated DBPs increased after FH+MF due to higher Br/DOC ratios caused by residual bromide. The PAC+MF process was more effective than the FH+MF process in removal of low molecular weight (MW) hydrophilic DOM, which was a precursor of dichloroacetonitrile. In addition to DOM characteristic (i.e. MW, aromaticity), an inorganic precursor (i.e. bromide) also had significant effects on DBP yields and bromine substitution. When bromide was abundant in water, bromine appeared to be more effectively incorporated into low UV-absorbing (i.e. less aromatic) DOM fractions and simple structural DBPs.

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 Main objective of this study was to understand the occurences of perfluorinated componds (PFCs) and their precursors in cosmetics. Thirty cosmetics were analyzed to determine 15 PFCs and 14 precursors by LC-MS/MS. PFCs formation potentials (PFC-FPs) were evaluated by oxidative conversion of various precusors to PFCs under a certain condition. In addition, time-of-flight-mass spectrometry (TOF-MS) was applied to examine non-target chemicals. Total concentration of 15 PFCs ranged from 146 to 8,170 ng/g-wet while that of PFC-FPs ranged from 75 to 93,200 ng/g-wet. In some foundations and makeup bases, concentrations of PFC-FPs were 11-199 times higher than those of PFCs. As a result of TOF-MS analysis on a foundation which included “C9-15 fluoro alchol phospates” as cosmetic ingredients, 7 kinds of polyfluoroalkyl phosphate ester were detected and these were suspected to form PFCs.

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 Huge amount of the chemicals are used in industry. Although the chemicals are statutory restricted, formation and/or transformation of them to hazardous chemicals in urban water cycling have not been taken into consideration. This research was aimed at establishing the formation potential screening tests of eight N-nitrosamines, four aldehydes and four trihalomethanes from industrial chemicals during oxidation treatments, i.e. ozonation, chloramination or chlorination. Evaluation of the results was also discussed to quantify the molar yield of the formation. Among the chemicals registered in PRTR, six chemicals were selected as the potential precursors according to the high potential of exposure in wastewater (calculated concentration in wastewater). The chemicals were subjected to the tests and seventeen data sets of the formation were obtained quantitatively.

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 Effluent tests of secondary effluent with high concentrations of dissolved metals were conducted based on biological responses of Ceropdaphnia dubia and Daphnia magna. The secondary effluent affected the survival and reproduction of C. dubia but did not affect the survival and reproduction of D. magna. Results indicate that C. dubia was more sensitive to the secondary effluent than D. magna. Toxicity identification evaluation tests indicated cation metals and ammonia as substances that caused effects of the secondary effluent on C. dubia. Effects of cation metals and ammonia on C. dubia were evaluated based on results of water quality analysis. Results showed the effect of nickel included in the secondary effluent on C. dubia. Toxicity identification test could detect the biological effect of dissolved cation metals in the secondary effluent used in this study.

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 This study investigated ultra-high solid anaerobic digestion (35°C and 20-30days HRT) of sewage sludge and ammonia stripping of digested sludge for the removal/recovery and inhibition of ammonia. At the influent TS 9-11%, the laboratory anaerobic digester was confirmed to perform well, showing VS destruction of 51.3% and gas production of 0.483NL/gVS. At the influent TS 12-15%, the performance was deteriorated, but was recovered when combined with ammonia stripping. The simple stripping device showed the average ammonia removal efficiency of 60-83%, and recovered nitrogen as ammonium sulfate. The results indicate that ultra-high solid anaerobc digestion of sewage sludge is possible up to influent TS 12-15%, as far as proper mixing and ammonia control are provided in digesters.

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 Two-phase anaerobic digestion process, consisting of hyperthermophilic acidification and thermophilic methane fermentation, coupled with subcritical water process as a pretreatment of thickened excess sludge was examined, aiming at enhancement of methane production ratio and anaerobic digestion efficacy. Batch experiments reveiled that subcritical water process at a 180 °C of temperature and 1 MPa of pressure for 60 min., was able to solubilize 50% of COD_Cr, 60 to 70% of protein, and 70% of total suger, and that improvement of solubilization and acid production increased methane production in an early stage in the following methan fermentation process. A continuous experiment also reveiled that the pretreatment by subcritical water process was able to improve removal ratios of COD_Cr, TS and VS, which means enhancement of sludge treatment efficacy. Adding a small amount of kitchen garbage, about 10 %, to thickened excess sludge treated by subcritical water process achieved more stable operation.

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 In local cities with decentralized small wastewater treatment plants (WWTPs), centralized anaerobic digestion at a WWTP that accepts more sludge from others can serve as the energy hub of the region. Oxidation ditch processes are widely used in small facilities, and dewatering sewage sludge makes it easier to transport the sludge to a centralized WWTP. The applicability of dewatered sewage sludge to anaerobic digestion with simple operation was investigated by continuous and batch experiments. Biogas production of sewage sludge was 0.1-0.2 NL/gVS-added, and that from kitchen garbage was 0.7 NL/gVS-added. Codigestion of sewage sludge and kitchen garbage had synergistic effect on biogas production. Operational energy consumption was reduced by simple operation such as reduced withdrawal frequency and mixing of the digested sludge. A cultural test confirmed that the digested sludge can be used as a fertilizer.

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 In this study, three single-chamber Microbial Fuel Cells (MFC) were applied for wastewater of each different organic composition (actual wastewater, synthetic lactate containing wastewater, synthetic acetate containing wastewater) to investigate the influence of change in organic composition of acetate and lactic acid. As the result, the effect of the variation in organic composition was considerably different in each MFCs, the influence of MFC of actual wastewater treatment was lower than another MFCs. Furthermore, the changes of microbial community by the variation in organic composition was observed at Bacteroidetes and Proteobacteria at all MFCs. Acetobacterium was suggested to contribute to the lactic acid degradation process at wastewater treatment, and it suggest a retention of a bacteria of symbiosis with the exoelectrogen are the important factor to the performance stabilization of MFC for the wastewater treatment.

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 It has been known that in-sewer sediments significantly contribute to combined sewer overflow (CSO) loads. However, knowledge is limited on the behavior of in-sewer sediment. In this study, characteristics of the accumulation and entrainment of in-sewer sediment were analyzed in a drainage area of 42.2 km² using a distributed sewer model based on Ackers & White's theory on the sediment transport. It was found that there is a large spatial variation in the amount of sediment deposited during dry weather and entrained during wet weather. It indicated that spatial characteristics of sediment accumulation and entrainment should be considered in a sewer network in order to identify the significant sources of the CSO loads. Then the reduction of CSO loads was evaluated by removal of in-sewer sediment by flushing with water. The reduction of CSO loads by water injection for sediment flushing at 3 points was estimated and compared. The results showed that CSO loads were reduced by 18.3 % in the case of 32400 m³ of cleaning water. This study demonstrates that model analysis is useful to evaluate the effectiveness of the CSO reduction measure by the removal of in-sewer sediment by flushing with water.

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 In this study, in order to clarify the mechanism of hypoxia occurring in the northern part of Isahaya Bay during summer season, a multiple regression analysis was conducted by using dissolved oxygen (DO) in bottom layer and water quality data. The results indicated that DO in bottom layer had a negative correlation with water temperature (difference between surface layer and bottom layer), salinity (difference between bottom layer and surface layer), and surface layer's chlorophyll-a (data collected 12 hours before). Especially, it has been proved that a difference between surface layer and bottom layer in water temperatures could have a major influence on the dynamic behaviors of DO in bottom layer. Moreover, the phenomenon at the observation tower B4 was affected by the water depth which a thermocline was formed. Furthermore, based on the tidal current and DO sequential data, near Kamachiku's waterfront, it was confirmed that hypoxic water occurred. This hypoxic water occurrence was due to the consumption of DO that inflowed from the bottom layer water column near observation tower B4.

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 In the Citadel area of Hue city, Vietnam, the discharge of septic tank effluent and untreated wastewater might cause fecal pollution in canals. However, it is difficult to assess the water pollution dynamics in the canal system which is affected by tidal action from an adjacent river. By sampling campaign, the concentration of E.coli exceeded the Vietnamese standard at all the points and it was found that the averages of EC and NH₄-N concentration at the inner canal were higher than the surrounding outer canal which is connected to the river. At the inner canal, continuous monitoring results showed the existence of polluted water mass at the center part where EC kept higher than the boundary points between the inner and outer canals. In addition, near the downstream boundary, EC becomes high during ebb tide and low during flood tide. The 1D water quality model was constructed to discuss the behavior of the polluted water mass. The model simulation reproduced the tendency of EC change at the inner canal and showed that the polluted water mass would vanish due to increased canal flow rate by width enlargement at the upstream boundary.

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 In this paper reports the results of purification experiment of the leachate from the tunnel rock muck including selenium, and purification experiment of the river water including arsenic, using plants which absorbing heavy metals named Eleocharis acicularis. In the leachate experiment, we measured the time course in 90 days of selenium concentration of the leachate and the selenium content of the E. acicularis which were floated interior water storage tank on-site. In the river water experiment, we poured the river water 300 L in two days to the artificial channel which was laid with E. acicularis mats to measure the change of the arsenic concentration of the river water and the arsenic content of the E. acicularis. As the results of water storage tank experiment, reduction of serenium concentrations of the leachate were confirmed from 0.039 mg/L to 0.002 mg/L during 90 days. And we also confirmed the reduction of the arsenic concentrations of the leachate and E. acicularis in the artificial channel experiment. The arsenic concentration of river water decreased to approximately 60% of initial value, the arsenic content changed to 4.16 mg/kg after a 200 L was flow down. In addition, the amount of sample water was reduced to 41 - 64 % of initial value through evapotranspiration from the plants and the artificial channel.

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 A Down-flow Hanging Sponge (DHS) reactor combined with a primary sedimentation tank (PS+DHS system) was operated over 1,000 days to investigate the effect of HRT on treatment efficiencies. Insufficient effluent water quality was obtained when an HRT was set at 0.8 hours for DHS. After elongating HRT to 3.2 hours, high effluent water quality in terms of organic matter removals (>90% for BOD and SS) and microbial indicators (2.73 log for F.coli and 3.15 log for T.coli) was achieved. A removal efficiencies of sanitarian microbial indicators of an activated sludge process treating the same sewage were 2.55 log for F.coli and 2.19 log for T.coli, indicating that the PS+DHS system has comparable removal efficiencies to the activated sludge process. From the result obtained, the PS+DHS system with longer HRT (3.2 hours) can be an alternative process of an activated sludge process for sewage treatment.

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 Soil aquifer treatment (SAT) is an eco-friendly water reclamation process. For implementing SAT system, the understating on the impact of the surface layer of SAT for virus removal is an important aspect for a SAT system with a short retention time in urban area. This study evaluated the adenovirus and rotavirus removals by SAT with a pilot-scale reactor and laboratory-scale columns (saturated and unsaturated conditions). It was found that higher virus removal was observed in the surface layer especially under the unsaturated condition than in the lower part of the soil. Also, virus type affected virus removal efficiency. This shows that for the implementation of a SAT system, it is necessary to assess the removal efficiency of the virus of concern during SAT.

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 This study was evaluated the inactivation and photoreactivation of a drug resistant Escherichia coli by irradiation with visible light after irradiation with low-and medium pressure UV lamp. When the 3 log inactivation of the drug resistant Escherichia coli which is resistant to six types of antibiotics (ampicillin, gentamicin, cefdinir, kanamycin, tetracycline, sulfamethoxazole, and trimethoprim) , (Six-antibiotic resistant E.coli), and is not resistant to these antibiotics including imipenem and levofloxacin (Non-antibiotics resistant E.coli) was expected in consideration of maximum photoreactivation, the total relative germicidal effective dose was required more than 15mJ/cm² by the irradiating of low- and medium pressure UV lamps to Non-antibiotics resistant E.coli. Meanwhile, Six-antibiotic resistant E.coli was required to more than 15mJ/cm² of the total relative germicidal effective dose by irradiating of low pressure UV lamp and 20mJ/cm² or more by irradiating of medium pressure UV lamp.

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 We studied the rate of norovirus removal for each reclaimed wastewater use application, selection of treatment and disinfection processes which can satisfy the removal rate, and the estimation of the cost and energy consumption of each process.
 The results indicated that the highest norovirus removal rate was required in the recreational water use due to the larger water intake. The trend of construction cost and energy consumption required to achieve certain risk level increased in the order of chlorine disinfection < ultraviolet disinfection < ozone disinfection, and maintenance costs of chlorine disinfection was almost equal to that of ultraviolet disinfection. As the virus risk control level improved, life cycle cost and energy consumption also tended to increase. We proposed the framework to select the adequate treatment process from the viewpoint of microbiological risk control, life cycle cost and energy consumption.

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 Cow urine is not reused as liquid fertilizer which can be an alternative secure phosphate resource. This paper aims to confirm the validity of a simulation model for precipitation stoichiometry of precipitations by equilibrium calculation, to identify the chemical spices of the precipitations, and to investigate the effect of dilution by cleaning water on phosphate recovery. As a result, Phreeqc equilibrium solver could be agreed to experimental result at equilibrium condition. XRD analysis and element composition of the precipitations showed existence of calcite and magnesium phosphate which the simulation identified as magnesium ammonium phosphate. Both experimental and simulation result indicated that the dilution of urine reduced of the recovery ratio of phosphate while its effect was small at high initial concentration of phosphate. This indicates the simulation can evaluate the recovery ratio from the initial condition

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 Firstly, the metals removal from acidic extract of sewage sludge incinerated ash was investigated using an electrodialyzer. Through the elecrtodialysis at a pH of 0.5 during 10 hours, about 90% of Al, Zn and Cu in the extract were removed, while 60% of P was retained in the extract. Secondly, the extract after the electrodialysis was neutralized with 28% ammonia water and was dried at 45°C. The water soluble phosphorus content of the dried sample was about 90%. The composition of the dried sample met the quality criteria required for the chemical fertilizer. The analyses of the dried powder sample with the XRD and FESEM-EDX showed that the dried sample would be mainly composed of (NH₄)₂SO₄, (NH₄)H₂PO₄ and P₂O₅. These findings suggest that the dried sample recovered from acidic extract of the sewage sludge ash could be recycled as a raw material of fast acting fertilizers.

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 In order to recover the phosphorus from sewage sludge and to prevent from the trouble at incineration plants caused by phosphorus in sludge, fractionation analysis of phosphorus in sewage sludge of eleven municipal sewage treatment plants and acid treatments were performed. The results of fractionation analysis showed that phosphate fractions and particulate phosphate fraction in digested sludge ranged 73 to 89% and 24 to 62%, respectively. The results of acid treatments showed that particulate phosphate fraction could be dissolved to phosphate ion thoroughly at the pH condition of 2 with sulfuric acid, 5 with citric acid, or 4 with acetic acid. Judging from these results, dissolved fraction of phosphorus in digested sludge will be able to increase more than doubled using with acid treatment.

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 In this paper, the methodology and efficiencies of recovering phosphorus from three aquatic plants, Trapa natans L., Potamogeton maackianus, and Egeria densa, were discussed. By soaking the dry powdered biomass tissue in distilled water for 24 hours, 50 to 81% of phosphorus was extracted into the liquid phase. More than 89% of the extracted phosphorus was precipitated as calcium phosphate although it was concerned the precipitation is inhibited due to phytic acid, a chelating agent, and various organic substances. Overall phosphorus recovery ratios were 41~76%.

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 The effect of water circulation on the treated water quality of Johkasou was evaluated through cluster and principal component analyses of the measurement results for three Johkasou units that had different usage conditions (the ratio of the practical to the designed number of users being 0.8, 0.14 and 0.29, respectively). Water circulation promoted denitrification, leading to decreases in the concentration of total nitrogen in the water after treatment; however, it did not bring about observable changes for the removal of BOD. Cluster and principal component analyses showed that all water quality indices could be classified into two groups relating to the organic loadings and nitrification-nitrification, respectively. Statistically weak correlation revealed between these two groups suggests that water circulation is effective for the removal of nitrogen; however, for the removal of BOD, different approaches are necessary.

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 Effects of water-saving devices on domestic wastewater treatment facility, Johkasou were investigated. After installing all water-saving devices such as toilet bowl and washing machine, water consumption decreased by 22%, and increase in BOD concentration in domestic wastewater was observed. In connection with the changes of influent characteristics, effluent BOD concentration of Johkasou increased from 14.8 to 21.4 mg/L. However, effluent BOD load which was calculated by multiplying BOD concentration and water flow volume, showed no increase because of the decrease of water volume. In the range of water-saving efficiency up to 22%, it was found that treatment performance of Johkasou did not turn worse. Furthermore, effluent BOD load decreased by 24.8% when aerobic-anaerobic circulation was conducted in Johkasou.

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 Trichloroethene (TCE) is a major groundwater contaminant in many developed countries. TCE is known to be degraded by phenol hydroxylase (PH) aerobically. Although many phenol-utilizing bacteria have been isolated, each bacterium has its own TCE degradability. Reasons on the difference in TCE degradability among isolates are not clear in many cases. Here, we have developed a method able to evaluate TCE degradability of PH gene itself by using a common host and the tac promoter for constitutive expression. A green fluorescent protein gene was also used as a reporter. These genes were integrated into chromosome of a host strain by using a Tn5 transposon vector. Transconjugants having each PH gene were isolated, and TCE degradability were compared each other. Results showed that TCE degradability was different among 6 PH genes. The fluorescence analysis showed that transcription level and the degradation efficiency were significantly different among them.

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 In urbanized areas where sewage system has been developed, noroviruses excreted from patients are collected in sewage treatment plants. Therefore, the concentration of noroviruses in sewage has been proposed as an indicator of gastroenteritis cases in the treatment area. In this study, we tested the applicability of norovirus monitoring in sewage as an early warning system of infectious gastroenteritis. Sewage samples were collected weekly from April 2013 to October 2015, and the temporal relation between norovirus concentration in sewage and the number of gastroenteritis cases reported in the study area was evaluated using cross correlation analysis. We also compared norovirus genotypes detected in sewage by pyrosequencing and those detected in clinical samples. As a result, significant correlation was observed between norovirus GII concentration in sewage and the number of gastroenteritis cases without a lag time (R = 0.57–0.72), implying that the concentration of noroviruses reflects the number of infected people when the sample was collected. Most of the norovirus genotypes or strains detected in stool samples were also found in sewage samples and they changed similarly over time during the study period. Considering that it takes one or two weeks for the number of gastroenteritis cases to be released to the public, norovirus monitoring in sewage is a promising alternative for the early warning system of gastroenteritis.

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 Pepper mild mottle virus (PMMoV) and Aichi virus were detected from cultivated oysters and their potential as indicator for Norovirus contamination of oysters were examined. Both of the detection frequency and amount of RNA of PMMoV in oysters were higher than those of Norovirus, showing a potential of PMMoV as the Norovirus indicator. Then, we proposed a practicable usage of PMMoV to estimate the probability of Norovirus-positive oysters. When PMMoV are detected at a high concentration than 10⁶ copies/g-DT, indicating over 77% of oysters contaminated with Norovirus, we can skip the detection of Norovirus to reduce the time and cost for test.

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 The present study proposes an approach for determining a target value of enteric virus removal in wastewater reclamation processes based on monitoring datasets of source water quality and tolerable annual disease burden. In the proposed approach, probabilistic distributions of norovirus (NoV) concentration in the influent of domestic wastewater treatment plant were estimated, and tolerable concentration of NoV in reclaimed wastewater was determined to meet the tolerable annual disease burden (10^-6 disability adjusted life year per person per year) based on quantitative microbial risk assessment (QMRA). The target values of NoV removal were then computed using the probabilistic distributions of NoV and the tolerabole concentration according to six exposure scenarios for water reuse. It is required to monitor the virus concentration in untreated wastewater even after the operation of wastewater reclamation and reuse system is started. It is also important to continusouly update models and assumptions in QMRA for revising locally appropriate level of performance target value of enteric virus removal in a wastewater reclamation system.

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 Quantitative detection of health-related microorganisms is of importance for risk assessment of environmental context, but quantitative real-time PCR (qPCR) alone meets a difficulty to distinguish viable and dead cells. Propidium monoazide (PMA) treatment followed by qPCR has been introduced to overcome this issue. In this study, a LED lamp, instead of a halogen lamp, was used for cross-linking of PMA and DNA, and the effects of filtration for the enumeration of viable Escherichia coli by PMA-qPCR was investigated. PMA-qPCR was applicable to suspended cells after the treatment with 100μM PMA followed by 15 min exposure to a LED lamp. On the other hand, PMA-qPCR was not able to distinguish viable and dead cells after filtration. Cell treatment with LIVE/ DEAD BacLight Bacterial Viability Kits indicated that the most of cell after a filtration procedure were damaged, suggesting the filtration procedure is one crucial point for PMA-qPCR of filtered samples.

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 Peptide-ligands bind to Shewanella algae cells were selected from a random 12-mer phage display peptide library. 2 rounds of biopanning against S. algae cells were carried out to enrhich phage clones displaying the specific peptide-ligands. After the second round, eluted phages from S. algae cells were cloned and analyzed the binding specificity to the target cells by fluorescence signal detection using a Tyramide Signal Amplification. Four phage clones determined to be higher binding specificity were selected and subjected to cell separation using magnetic beads. As the results, magnetic beads with the selected phage clones could collect the target cells compared with magnetic beads without phages. Therefore, phage displayed peptide combined with magnetic beads may be an applicable technique for specific microbial cell separation.

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 A coastal final disposal site is important and essential infrastructure for our country. However, decomposing of organic matters and washout of contamination components are very slow in that place and there is a concern about accelerated stabilization. Moreover, it is known that the fine particle fraction of municipal solid waste incineration ash contains more contamination components, therefore removing the fine particle fraction from municipal solid waste incineration bottom ash will reduce the contamination of sea water in the final disposal site. Therefore, the purpose of the study is to clarify the effects of removing the fine particle fraction on the stabilization of coastal final disposal site.
 In order to achieve the purpose of this study, experiments using a large scale tank filled with the bottom ash imitating a coastal final disposal site were conducted two times. At the first time, the bottom ash without classification treatment was filled in the tank. At the second time, the bottom ash after removing the fine particle fraction was filled in the tank. After the filling, sea water flow was given in the tank, and the pH, EC, total organic carbon and total nitrogen of pore water and leachate were analyzed. Also, the flow rate of leachate was measured to know the permeability of the sedimentary bottom ash layer. As a result, it was demonstrated that the removing fine particle fraction increased permeability of the sedimentary layer and reduced concentrations of contamination components in leachate.
 Therefore, the removing fine particle fraction has the effect on increasing permeability of the sedimentary bottom ash layer and improving.

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 For the establishment of a sustainable society, the utilization of ash generated from municipal solid waste incinerators (MSWIs) is an important challenge. The production of slag using a melting process has been a major recycling process in Japan regarding the control of toxic substances such as dioxin and heavy metals, but the ash melting process is expensive and energy-intensive. Therefore, in this study, we focused on accelerated aging technology using exhaust gas from gas engines for the utilization of MSWI bottom ash. As gas engines have been installed to ensure the cessation of operation in an emergency such as a natural disaster or accident, such engines are always used to produce electricity in MSWIs. With this technology, by exposing bottom ash to exhaust engine gas while controlling the ash temperature between 300 and 400°C, the amount of leached heavy metal can be decreased. The advantages of this technology are that it is cheaper and requires less energy than the ash melting process. According to previous studies, accelerated aging resulted in the level of leaching of heavy metals, mainly lead, being lower than the upper limit in environmental standards. However, there remained an insufficient understanding of the mechanism involved. The purpose of this study was thus to investigate the mechanism of stabilization of lead in bottom ash by accelerated aging. After accelerated aging at a temperature of 300°C and an exhaust gas (kg) to bottom ash (kg) ratio of 4:1, bottom ash particles were classified as being over 1 mm in size. Under these conditions, the concentration of leached lead was below the upper limit in environmental standards. It was considered that the lead in bottom ash was not only carbonated but also taken into insoluble minerals, as determined by sequential chemical extraction and X-ray analysis.

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 Fluorine immobilization mechanism of apatite treatment for electric arc furnace steelmaking slag was investigated. Apatite treatment immoboilized fluorine strongly and prevented from secondary leaching of fluornie. This study found that fluorapatite formation mainly contributed to fluorine immobilization. Synchrotron X-ray diffraction analysis showed that fluorapatite was generated directly from amorphous calcium phosphate, not hydroxide/fluorine ion-exchange reaction inside hydroxyapatite. When fluorine was adsorbed to amorphous calcium phosphate, fluorapatite was synthesized soon and encapsulated fluorine inside its crystal structure. On the other hand, fluorine adsorbed to hydroxyapatite could be released easily before slow fluorapatite formation. Sodium alginate and chitosan could generate organic-apatite complex with multi-layer structure and relatively homogeneous surface. When these organic-apatite complexes could be synthesized on slag surface, however, they gave less fluorine immobilization than normal apatite treatment and promoted fluorine leaching. Competitive adsorption between fluorine and alginate/chitosan onto amorphous calcium phosphate might inhibit fluorapatite formation.

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 The Planungszelle (PZ), which is an approach to consensus building, was carried out to extract desirable future (in 2050) scenarios of water use system and we analyzed how information providing and discussions about water use system affect participants' preferences to attributes of water use system or their scenario choosing. In addition, a new PZ method that ensures the diversity of participants was developed by applying the CLT(Central Location Test) system. Providing information helps participants to cognize the trade-off among attributes, and discussions accelerate their understandings of water use system and considerations to others' preferences. Participants finally support the scenarios in which more than one attribute would be improved through these processes.

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 In the depopulating society, water supply systems would be affected by the shift of water demand patterns arising from the transition of the city structure. In this study, five scenarios of the future urban structure were proposed for a New Town at suburban Tokyo, and the water distribution network was examined in terms of the hydraulic retention time in pipelines, replacement cost of old water distribution pipes, and pump energy for water supply to tall buildings. In addition, restructuring of the distribution systems was suggested and evaluated for each scenario.

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[in Japanese]

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 The state of the fish movement changes during the duration and it is shown that fish move to the low velocity zone or swim upstream. The acceleration and the velocity are the factors that effect on the swimming behaviors. The porpose of this study is to make clear that effects of the negative acceleration and the velocity during deceleration on the swimming behaviours of Nipponocypris Temminckii (Kawamutsu). The peak velocity was fixed, the negative acceleration and the latter velocity were changed. The swimming behaviors in open channel were recorded with a digital video camera. As a result, the threshold value of the negative acceleration that Nipponocypris Temminckii decides the migration direction is approximate -0.5(1/s²). Nipponocypris Temminckii migrated upstream when the negative acceleration was smaller than -0.5(1/s²). On the other hand, Nipponocypris Temminckii migrated downstream when the negative acceleration was greater than -0.5(1/s²). In addition, it is suggested that the deceleration trigger upstream migration. In contrast, there is little effects of the latter velocity on swimming behavior.

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 It is important to secure the rest area for fish. Fish has the ordinary and dark muscle. When fish uses ordinary muscle, fish got tired. In such a situation, fish needs a rest. In this study, rest characteristic of ayu (Plecglossus altivelis altivelis) with changing the width and the number of interception was researched. The migration rates of ayu were obtained with the aid of a digital video camera. It was found that the migration speed increased with an increase of flow velocity, because ayu swim in keeping with flow velocity for prevent to be drift towards downstream. The total time of the rest increases with an increase of flow velocity.

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 In this study, the authors consider fish behavior in a rocky ramp fishway with a transverse slope. As the efficiency of a fishway mainly depends on the structure (shape, bottom slope, ruffle size) and hydraulics (velocity, depth), these matters were inspected using a small open channel.
 As the results, 1) in spite of discharge is not so large, higher migration rate is shown. In this case, the region in where the velocity is suited for the run-up of fish, is formed easily. 2) Tribolodon hakonensis can find a convenient flow for their migration, and in this case Tribolodon hakonensis can take a rest easily for a while in the channel, because flows with various velocities appeared in the cross section of fish way. 3) In addition, total run up time becomes longer. 4) If Tribolodon hakonensis stays for a longer time in the fish way, it invites more danger from attack by birds and another fish, in the rocky ramp fishway with transverse slope. 5) Therefore, it needs to consider on the more efficiency and safety for fishway.

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 Activated carbon/TiO₂ composites were synthesized for the removal of 1,4-dioxane in landfill leachate. The composites had photocatalytic activity and almost equivalent adsorption capacity to that of woody activated carbon used for the synthesis, and 1,4-dioxane in pure water was simultaneously adsorbed and decomposed by the composites. As a result of evaluating inhibitory effect of coexistent substances such as inorganic ions and dissolved organic matters, it was clarified that chloride inhibited photocatalysis and humic acid reduced the rate of adsorption and photocatalytic decomposition. Although the simultaneous removal of 1,4-dioxane and dissolved organic matters in biologically treated landfill leachate was accomplished by using the composites, coexistent substances strongly inhibited the photocatalytic decomposition of 1,4-dioxane. Therefore, the authors proposed a sequential treatment process, adsorption followed by decomposition. They realized reduction of 1,4-dioxane in the leachate to less than the effluent standard value and the regeneration of the composites by photocatalytic decomposition of 1,4-dioxane.

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 A part of wastes containing radiocesium which was spreaded to the environment by the accident at Fukushima Daiichi nuclear power plant have been disposed in controlled landfill sites. The objective of this study was to examine the usage of natural minerals; three types of zeolite, two types of illite, and vermiculite, as a Cs adsorbent to prevent Cs from leaking with leachate from the controlled landfill site. The results of a sorption test using actual leachate showed that Cs sorption ratio did not depend on Cs concentration in leachate for zeolite, but illite and vermiculite could sorb Cs more efficiently at lower Cs concentration in leachate. Additionally, the amount of sorbed Cs has a high correlation with cation exchange capacity. The results of an extraction test showed that all of the minerals, especially zeolite, had high Cs fixation capacity. Since there was a high correlation between Cs fixed fraction and Radiocesium Interception Potential (RIP), it was suggested that Cs fixation capacity can be estimated using RIP.

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 Magnesium-based and calcium based compounds have been expected as adsorbents for arsenic removal from contaminated water. However, the adsorbents which have been used to purify arsenic contaminated water would contain a large amount of arsenic. If the spent adsorbents were dumped into environment without an appropriate treatment, a secondary environmental pollution might be caused by leaching of arsenic from the spent adsorbents. Therefore, it is necessary to evaluate environmental stabilities of the spent adsorbents.
 In this study, the soil leaching tests on the spent magnesium-based and calcium-based adsorbents were conducted and the experimental data obtained were examined. From the results, the magnesium-based and calcium-based oxides and hydroxides were found to have higher environmental stability. In addition, in terms of secondary environmental pollution by leaching of arsenic from the spent adsorbents, the risk of the spent MgO-based adsorbent was illustrated to be the lowest among those of the tested adsorbents. On the other hand, the spent MgCO₃-based adsorbents showed considerably lower environmental stabilities and higher risks especially when those were dumped in sandy soils.

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 Leakage reduction can save the energy consumption of the pump for water transport and chemical costs in accordance with the water purification. To reduce the environmental load siginificantly, it is important to minimise excess pressures of distribution netwroks with water distribution system as a fundamental aspect of leakage management strategy. Generally, the preventive maintenance schemes such as updating aging pipes and repairing water leakage can effectively reduce leakage, however, these scheme requires a large cost. On the other hand, the operation control schemes such as operating supply pumps and pressure reducing valves expect to contribute a large effect with respect to low cost.
 In this paper, we focus on the operational control schemes and propose the idea to operate pressure reducing valves with relatively simple analysis. We have checked the excess pressure in a distribution network by analyzing the limited data acquired by a monitoring system and proposed an improved operation of pressure reducing valve. Through the solution above, the field data show the reduction of the minimum night flow, as a result , it brings about the effect of the leakage reduction.

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 In the Great East Japan Earthquake, it took a long time to recover from water outage because of many water pipes were destroyed. In the Bureau of Waterworks, Tokyo Metropolitan Government, for the purpose of shorten the restoration times from water outage, it has been actively promoting the renewal to the aseismatic pipes. However, it will take enormous cost and time to complete the renewal project. For the effective pipeline renewal plan, that must consider not only the aging of pipes, but also the earthquake damages of pipeline. Damages of pipeline caused by a earthquake is expected to occur at multiple locations at the same time. Therefore, it is difficult to predict the damage point, it is common to capture as a probabilistic phenomenon.
 In this study, focusing on the pipeline damage due to an earthquake. we tried to estimate outage water amount (rate) by using a Monte Carlo simulation analysis. In addition, we examined the effect of reducing the outage water amount due to the introduction of an aseismatic pipeline.

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