Acidic thermal treatment was examined with respect to treatment conditions and its efficacy when incorporated into anaerobic digestion of sewage sludge. In the batch study, the treatment temperature of 25, 100 and 180°C and initial pH of 6, 4 and 2 were applied. Methane production and sludge destruction was improved as the temperature was raised, whereas dewaterability was improved as the pH was lowered. Color was generated significantly at the temperature of 180°C. In the continuous experiment operated at the HRT/SRT of 20 days, the acidic thermal treatment at 170°C and pH5-6 for 1 hou was combined with anaerobic digestion in a post-treatment mode, using hydrochloric acid or sulfuric acid as the strong acid. Compared with the control digestor, the digestor incorporating the acidic thermal treatment showed 1.8-2.0 times more sludge destruction, 13-22% more methane production, 20-32% more dewaterability improvement. A disadvantage was again seen in color generation. Sulfuric acid caused more release of phosphorus from the sewage sludge, which enables efficient phosphorus recovery.

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One of the main disadvantages of anaerobic treatment of wastewater having low pH is that the operational cost is too high as there is a need to supply a considerable amount of alkali fromoutside. To curtail the cost by reducing alkali supply, a sequential multi-feed mode (distributed feeding) and effluent recycle mode were proposed, and verified by conducting experiment on a pilot-scale (2.5m³) thermophilic (55°C) multi-staged UASB reactor. Wastewater used for the study was alcohol distillery wastewater (shochu), one of the largely produced industrial wastewater in Japan. The sequential multifeed mode of operation (SMF 5; influent pH: 5.0, COD loading rate: 45kgCOD·m^-3·d^-1 (HRT: 12 h, influent COD concentration: 20, 900mgCOD·L^-1)), successfully made it possible to lessen alkalinity supplement (24% NaOH solution) by 67.2% compared to the single feed mode. As for the effluent recycle mode operation (ER 4; F: W: E=1: 4: 10, COD loading rate: 35 kgCOD·m^-3·d^-1 (HRT: 12h, influent COD concentration: 17, 400mgCOD·L^-1)), operation was possible without any supplement of alkalinity as the system reuses the alkalinity generated during the microbial metabolism.

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Bench-scale continuous digestion experiments were conducted with a thermophilic hydrogen-methane fermentation system, composed of a solubilization/hydrogen fermentation reactor and a methane fermentation reactor, using simulated garbage + toilet-paper as raw material. For promoting digestion in the solubilization/hydrogen fermentation reactor, part of the methane fermentation slurry was returned to the solubilization/hydrogen reactor to facilitate pH maintenance and microorganism enrichment. The solubilization and hydrogen fermentation reactor exhibited a biogas production rate of 0.06L/gVS. The hydrogen gas content of the biogas was 25-63%. The methane fermentation reactor exhibited COD_Cr removal rate of 74%. A semi-pilot scale plant for treating food leftovers and waste paper by hydrogenmethane two-stage fermentation was tested. Pre-treated strong slurry (VS 91, 900mg/L) was solubilized and digested under thermophilic hydrogen fermentation conditions of HRT of 2.1 d and recirculation ratio of 0.67. VSS removal rate at pH5.8 was found to be 52%, biogas production rate to be 0.16L/gVS.

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We investigated performance of a developed novel anaerobic down-flow hanging sponge (AnDHS) reactor for low-strength wastewater treatment. An artificial wastewater of 300-400 mgCOD/L was continuously fed over one year at 2, 4 or 6 HRT. Under the operational conditions at 20°C, HRT 2 hr and at 15°C, HRT 4 hr, 70-80% of total COD removal and 60-90% of methane recovery were achieved. Regarding operational mode, one through operation gave a better performance in COD removal compared with recirculation mode. The results of batch experiments feeding single substrate of acetate, propionate or sucrose demonstrated that AnDHS reactor is more preferable to very low-strength wastewater and this reactor had a great potential in the volumetric substrate-degrading activitie 2-3 times as large as that in the continuous experiment of restricted substrate concentration. In addition this reactor was faced with no trouble concerning sludge-retainment such as massive loss of sludge by washing through the long experiment over 500 days. This study showed that AnDHS reactor succeeded in high COD removal by methane fermentation without seeding biofilm and was obviously easier in maintenance than conventional anaerobic treatment reactors.

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The performance of thermophilic (55°C) and mesophilic (35°C) anaerobic digestion with ozonation were evaluated by pilot-scale experiments. Under thermophilic condition, the degradation efficiency of VSS compounds was 5.5% higher (85.3%) than that of mesophilic condition at 0.9-1.0kgTVS/m3/day and consumption of ozone per decomposed VSS was reduced by 18%. However, the biogas conversion was not improved due to remaining considerable organic fraction in soluble form. This fraction was found to be readily degraded by mesophilic microbes under mesophilic condition. Based on the results, the themophilic-mesophilic-phased digestion process with ozonation, where ozonated sludge was decomposed rapidly in the thermophilic digester and the residual soluble organic fraction in the thermophilic digested sludge was decomposed to biogas in the mesophilic digester, was developed. The new flowscheme performed 8.1% higher TVS degradation efficiency and corresponding more biogas conversion due to improvement of TVS degradation. Ozone consumption in the new flowscheme was 18% lower than mesophilic condition.

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In order to expand cultivation conditions of pH and temperature, a series of thermophilic L-lactate batch fermentation experiments of unsterilized garbage was investigated with fermented L-lactate cultural broth inoculum in consideration of semi-continuous operation. The results showed that L-lactate was produced under the set of conditions of pH 6.5 and 50°C with using the inoculation. On the other hand, D-, L-lactate was fermented under the set of conditions of pH 6.0 and 50°C. These conflicting respects would depend on the optimal growth conditions of Bacillus coagulans that is the L-lactic acid bacterium of the thermophilic L-lactate fermentation. The optimal growth condition of B. coagulans was reported at pH6.5-7.0 and around 50°C. A multiple regression analysis was applied to production of L-lactate on each L-lactate batch fermentation for evaluating effects of pH and temperature. This analysis indicated that decrease in temperature to 50°C and increase in pH to 6.5 would enhance its production in thermophilic L-lactate batch fermentation.

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The removal characteristics of pharmaceuticals such as antibiotics and analgesics by ultra-violet treatment were examined. The synthetic raw water of 20L which 30 kinds of pharmaceuticals were spiked simultaneously was injected to the reactor and each experiment was conducted by batch test using 3 kinds of UV lamps. The detection and quantification of each pharmaceutical was done by LC-MS/MS method. It was possible to detect the concentration of each pharmaceutical to order of μg/L. The result of batch test showed that the reaction rate coefficient of Cyclophospharmdie, which was not decomposed readily by UV treatment, was most highest in Lamp 1. But, there was no significant difference in the reaction rate of Diclofenac which was a kind of easily-decomposed pharmaceuticals in each Lamps tested.

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In recent years, many studies have revealed the presence of many pharmaceuticals in the water environment. Little information, however, is available about the influence of such pharmaceuticals on aquatic organisms. In this research, we conducted algal growth inhibition test of 55 pharmaceuticals using microplates as a substitute for conical flasks and investigated characteristics of the toxicities of 55 pharmaceuticals. Fifty-five pharmaceuticals had wide-ranging ecotoxicity values (EC50, NOEC, LOEC). The most toxic pharmaceutical of them was triclosan (EC50=0.00760mg·l^-1). Comparing with the 55 EC50 values can not demonstrate the relationship between toxicity and physicochemical characteristics of the individual pharmaceuticals but indicate that the toxicities tends to be determined by whether target sites of the individual pharmaceuticals exists in the algae. The tendency was especially found pronounced in antibiotics.

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In recent years, water pollution problem by Pharmaceuticals is interested mainly in Europe and U. S. In this research, we selected 65 compounds of pharmaceuticals as target compounds and we investigated in wastewater treatment plants using advanced treatment. The purposes are to determine the occurrence of pharmaceuticals in wastewater and to determine the behavior of pharmaceuticals during advanced wastewater treatment. As a result, 29 compounds among 65 compounds were detected in the influent by ng/L-μg/L order and some compounds which has not been detected ever were detected. It was confirmed that each compounds have some removal characteristics during activated sludge treatment process. Moreover, during the treatment process which used chemical coagulants, sand filtration and UV, selected compounds weren't removed too much. But, during ozonation process, almost selected compounds were removed below each limit of detection.

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In recent years, pharmaceuticals have attracted attention as new environmental contaminants. Their detections in the aqueous environment thanks to innovative analytical methods have been extensively reported in Europe and North America. The purpose of this study is to develop an innovative and timesaving method to analyze many pharmaceuticals in water samples by solid phase extraction and LC-MS/MS. In this study, the recoveries and the efficiencies of both extraction and ionization were evaluated in comparison with between an absolute calibration curve method and a “standard addition method at a single concentration.” The results showed that the standard addition method can correct more appropriately measurement values biased due to the extraction and ionization processes. Detection limits of 58 pharmaceuticals are between 0.66 to 59 ng/1 for a concentration factor of 200. Therefore, this method is useful for simultaneous analysis of pharmaceuticals in the aqueous environment.

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Four granular activated carbon (GAC) columns (GAC-1-GAC-4) were designed by packing two types of GAC achieved by pulverizing and sieving a market-available GAC (F-400/Filtrasorb/USA) into two particle size ranges (d=0.5-0.59mm and d=1.0-1.19mm). In parallel, four biological GAC columns (BAC-1-BAC-4) were also established by coating identical GAC columns with microorganisms detached from the river bed sediment at the river water sampling site. River water containing lower content of NOM was pumped continuously into the columns to examine the behavior of NOM. Besides, 17ß-estradiol (E2) was intermittently added into the river water with/without the addition of a peat water that contains a high NOM content to investigate the removal of E2 and the responses of all columns to the influent NOM increases. The results after running for about 3000 hours showed that:(1) NOM constituents (excluding non-adsorbable ones) were well removed over the wide range of molecular weights;(2) a portion of DOC species not reflective by UV260 was removed through degradation by attached microbes; and (3) E2 was readily removed via adsorption (for GAC columns) and a combination of adsorption/biodegradation (for BAC columns), with its removals being significantly higher than those of NOM.

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In recent years, pharmaceuticals and personal care products (PPCPs) remaining in water environment have become social problem in many advanced countries. The purpose of this research is to quantitatively evaluate the sorption charasteristics of three human antibiotics (levofloxacin: LVFX, clarithromycin: CAM, azithromycin: AZM) to activated sludge. When batch sorption experimental results were analyzed with the Freundlich model, l/n of CAM and AZM were almost the same level, while l/n of LVFX was higher. This tendency was also observed in three component mixed system. The specific amount of sorption per unit equilibrium concentration was in the order of LVFX, AZM and CAM, and this might predict the capacity of activated sludge against these antibiotics. When inactivated sludge was used, equilibrium concentration increased by approximetly 10 times at maximum compared with that for activated sludge. The reason of the increase of the concentration, might be that the microorganism of activated sludge have lost the ability of taking target antibiotics to the inside of the body.

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Few researchers have reported on influent or effluent load and the behavior of PFOS and PFOA, persistent fluorinated organic compounds. in wastewater treatment plants. In this study, water quality and quantity were investigated in a wastewater treatment plant (population: 570, 000), in September 2005 and January 2006. Main conclusions obtained are as follows: 1) More than 80% of PFOS and PFOA in an aeration tank were adsorbed to activated sludge and were likely accumulated in a wastewater treatment plant, 2) 84% PFOS decreased in an ultra-advanced treatment by ozonation and biological activated carbon and 3) the flux of PFOS and PFOA were 1.5, 10.0g/day in influent, 5.6, 12.4g/ day in effluent (flow: 185, 000m³/day), respectively.

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In treated sewage effluents, DNA damage toxicity and endocrine disrupting activity have been detected. But the responsible toxic substances have not fully been identified.
In this study, we concentrated treated sewage effluents at Kyoto city by Sep-Pak C18 cartridges and eluted with methanol and acetone. The 50% methanol extract and the 100% methanol-acetone extract were fractionated by HPLC and three bioassays including umu test, a Bacillus subtilis rec-assay and a yeast AhR reporter gene assay were applied to each fraction. The results showed different patterns in three bioassays. By using umu test, the activity of DNA damage toxicity was detected in fractions of the 50% methanol extract. The Bacillus subtilis rec-assay and the yeast AhR reporter gene assay indicated DNA damage toxicity and AhR ligand activity in different fractons of the 100% methanol-acetone extract. Furthermore, Acid Blue 9 classified into acid dye was contained within the 50% methanol extract fraction. But DNA damage toxicity of Acid Blue 9 was not detected by umu test.

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Dehalococcoides bacteria dehalogenate chlorinated ethenes such as trichloroethene (TCE), cisdichloroethene (c-DCE), and vinyl chloride (VC). TCE reductive dehalogenase gene (tceA), is known to be responsible for mainly TCE and c-DCE dehalogenation. We obtained several tceAs by PCR from TCE-contaminated sites in Japan. After DNA sequences of tceAs were determined, phylogenetic analysis was conducted. The genes of tceA obtained in Japan were phylogenetically different from those reported in USA. All tceAs were compared each other and consensus regions were used to design primer pairs and hybridization probes to detect tceA by quantitative real-time PCR (qPCR). The developed method successfully detected tceA in a field where we conducted biostimulation for TCE removal. The increase of tceA concentration in groundwater was well correspond to the decrease of c-DCE. A certain type of tceA was observed at a monitoring well during a whole treatment period.

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Seasonal overgrowth of cyanobacteria such as Microcystis aeruginosa (M. aeruginosa) is one of serious problems in semi-closed water area including reservoirs. It is known that algogenic organic matters bring about the inhibition of coagulation on the flocculation process in drinking water treatment systems. However, the inhibitory organic matters produced by algae have remained to be elucidated. In this study, phage display library of proteins from M. aeruginosa was used to isolate algal proteins responsible for the coagulation inhibition. Several algal genes coding possible inhibitory proteins were obtained by biopanning using polyaluminum chloride. Amino acid sequences of proteins deduced from the obtained gene suggested that hydroxyl groups in serine and threonine, formamide groups in glutamine and aspargine, thiol groups in cysteine and carboxyl groups in glutamic acid and aspartic acid were involved in the coagulation inhibition. The result of the homology search suggested that metallloenzymes such as glycosyl transferase could be also responsible for the coagulation inhibition.

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The phylogenetic diversity of PHA synthase genes (phaC) in activated sludge from three different fullscale wastewater treatment plants was investigated. The PHA synthase genes in activated sludge from three municipal wastewater treatment plants were analyzed by PCR with a C1226f-CPr primer set followed by cloning and DNA sequencing. The clone library from Plant A had a simpler profile, and one of the clones occupied about 50% of the total clones. On the other hand, the clone library from plant N showed higher diversity. When the DNA sequences were translated into amino acid sequences, the similarities of the clones to known PHA synthase were found to be higher than 43%, indicating that the obtained sequences are most probably PHA synthases. The overlaps of the clones from each plant were small, and on the constructed phylogenetic tree, clones from each wastewater treatment plant had a tendency to form their own clusters. Some of the clones were found to have similarities to the known phaC genes to the extent of more than 90%. Some of the clones formed distinct clusters with similarities to the known phaC genes at around 43-49%, indicating the existence of phaC genes not reported from pure cultures.

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Applicability and reliability of two-pass tyramide signal amplification-fluorescence in situ hybridization (two-pass TSA-FISH) with PCR generated polydeoxyribonucleotide probes, specific for chromosomal encoded gene, methyl coenzyme M reductase (mcr) in Methanococcus vannielli, was tested and evaluated. The probes were labeled with dinitrophenol (DNP) and the efficiency of probe-labeling was improved by optimizing the concentrations of DNP-labeled nucleotide and Mg²⁺ in PCR mixture. The target mcr gene was successfully detected, which was again verified by the disappearance of the signals after treating the target with DNase prior to hybridization or washing with high stringency buffer. However, a few nonspecific signals were observed when the method was applied to pure cultures of Methanoculleus bourgensis and Escherichia coli.

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Presence of anaerobic ammonium oxidation (anammox) process was investigated in low ammonium-fed solid-phase denitrification bioreactor. A promising application of solid substrates for denitrification has been appeared since last decade and this type of denitrification here termed as solid-phase denitrification. Bioreactor was operated for 300 days in a temperature-controlled incubator. An immobilized biomass of activated sludge and anaerobic granules was used as inocula in the bioreactor and solid biodegradable plastic as a carbon source. Nitrogen mass balance showed that the average nitrogen removal efficiency in the bioreactor was 80%. The combined results of nutrient profiles, 15N-labelling techniques and qualitative fluorescence in situ hybridization (FISH) probe confirmed that anammox bacteria were active in the bioreactor. This clearly demonstrates that both anammox and denitrification processes work symbiotically in low ammonium concentrations under the support of solid substrates. It revealed that solid substrates not only serve as constant sources of reducing power for denitrification but also creates the favourable condition for anammox process by utilizing dissolved oxygen during the degradation of solid substrates.

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Anaerobic acetate-oxidizing bacteria were identified in the up-flow anaerobic sludge blanket reactor (UASB) applied to the low temperature treatment of sulfate-added wastewater of deicing fluid. Clone library analysis of PCR-amplified 16S ribosomal DNA was employed to identify bacteria, in which acetate was supplied as an electron donor. Identified clones were dominated by those derived from Citrobacter freundii and Desulfomicrobium baculatum in the enrichment culture incubated at 10°C, and those from Clostridium celerecrescens and Desulfovibrio sp. in the enrichment culture incubated at 30°C. Almost all of the cells were detected by FISH analysis using only two kinds of probes specific for hydrogen-utilizing sulfate-reducing bacteria and for either Citrobacter freundii or Clostridium celerecrescens in the both enrichment culture. Those two kinds of bacteria could be an acetate-oxidizing member in each culture. FISH analysis revealed that Citrobacter freundii, Clostridium celerecrescens and hydrogen-utilizing sulfate-reducing bacteria actually existed in the UASB, and the ratio of them to DAPI-stained total cells were about 2%, 3% and 6%, respectively.

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Anaerobic benzene degradation is a remarkable tool for bioremediation of contaminated soil and ground water. In this study selective cultivation of benzene degrading anaerobic microbial communities was performed by successive dosing of benzene into soil samples collected from lotus field. PCR-DGGE analysis revealed considerable progressive change in the Bacterial communities whereas negligible change among the Methanogenic Archaea. According the result from ¹³C₆benzene Stable Isotope Probing, some bacteria (mainly in the heavier fraction of ¹³C-DNA) shared 85% homology in 16S rRNA gene with Syntrophus aciditrophicus SB and Syntrophus gentianae which are known to have symbiotic relationship in anaerobic benzoate degradation. However based on such low homology, the bacteria obtained in this study cannot be certainly identified. This result helps to judge natural attenuation in contaminated soil.

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Sulfate reduction and denitrification using cedar as organic carbon source were examined in an anaerobic biological filter reactor and an anoxic biological filter reactor. In the anaerobic reactor packed with cedar chips, sulfate reduction occurred and bicarbonate was produced. It was estimated that sulfate reducing bacteria utilized cellulose. In the anoxic biological filter reactor packed with ceder chips, nitrate decreased and bicarbonate increased. It was estimated that heterotrophic denitrification mainly occurred in the attached biofilms, although sulfate reducing bacteria coexisted with sulfur denitrification bacteria inside of wood. Microbial community of sulfate reducing bacteria and sulfur denitrification bacteria was examined by a FISH method. Desulfobacter spp.and Desulfonema spp. were most common sulfate reducing bacteria detected in the anaerobic biological filter reactor. In the anoxic biological filter reactor, only Desulfonema spp.was detected in the attached biofilm. Sulfur denitrification bacteria such as Thiomicrospira denitrificans and Thiobacillus denitrificans weren't observed in the attached biofilm.

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Quantitative PCR method for 16S rRNA gene of Microlunatus phosphovorus was developed utilizing Quenching Primer PCR (QPrimer-PCR). PCR mixture and condition were optimized. Melting curve analysis and sequencing results revealed that only the target M. phosphovorus DNA were PCR amplified, without amplification of the nontarget sequences. We quantified M. phosphovorus in five laboratoryscale enhanced biological phosphorus removal (EBPR) activated sludge processes fed with different carbon sources. The abundance of M. phosphovorus varied according to type of carbon source. In addition, M phosphovorus existed in full-scale wastewater treatment plants regardless of type of treatment methods.

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Ozone-added activated sludge system has been developed for improving treatment operation. Although ozone added activated sludge system was originally developed in order to reduce excess sludge production, it is expected that its direct ozonation to activated sludge system can also remove some biorefractory compounds chemically, and the treatment efficiency and stability can be increased as results. In this study, low ozone loading condition was set, and treatment characteristics of continuous operation and effects of ozone adding on both composition of microorganisms and their biological activity were investigated. Moreover phenol was used as a biorefractory compound in wastewaters and the treatment characteristics were investigated with lab scale experimental setups. It is made clear that direct ozonation to activated sludge within a range of 6.7mgO₃/gSS does not inhibit biological activities and biorefractory compound (phenol) can be promptly removed chemically. On the other hand, the experimental case without ozonation can not remove phenol quickly and biological activity is inhibited by existence of phenol. These results suggest that ozone-added activated sludge system can treat wastewaters which contain biorefractory compounds effectively and stably. The possibility is also verified from the ovservation of microorganisms activity, and composition of protozoa and metazoan in continuous treatment.

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The contribution of PHA-accumulating organisms to acetate uptake was estimated by the batch experiments using activated sludge sample taken from full-scale wastewater treatment plant and dual staining of Nile blue A and DAPI was applied to activated sludge sample in order to evaluate the abundance of PHA-accumulating organisms. The results suggested that 20 to almost 100% of acetate had been taken by the member of Nile blue A positive cells and their population accounted for 10 to 20% in activate sludge incubated under aerobic condition. In order to estimate the contribution of Candidatus “Accumulibacter phosphatis” and Candidatus “Competibacter phosphatis” to acetate uptake, their population were quantified by fluorescent in-situ hybridization (FISH) analysis, and they accounted for 10 to 90% of population of Nile blue A positive cells.

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In snowy and cold area in Japan, road administrators spread de-icing salts on roads to ensure safe driving in the winter. The quantity of de-icing salts has increased every year since the use of studded tires was prohibited. Some people have expressed their fear that scattering de-icing salts that havebeen spread damages roadside environments. It is necessary to spread de-icing salts in order to ensure safe driving with minimum harming the natural environment.
So the purpose of this research is to ascertain the relations between de-icing salts and their impact of road side plants. This is a report on surveys of as follows:
On site experiment to confirm the possibility of the impact.
On site experiment to clarify spread of de-icing salt.
Laboratory experiment and document survey to set threshold level.
On site experiment salinity of roadside soil.
From the results, de-icing salts have little influence on herbaceous plant, so indicators shows under threshold level in spring, summer and autumn, because herbaceous plants are snowy in winter. De-icing salts have possibility to influence trees in from 3 to 5 meters from road edge.

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Since paint is being used in various places, it may contain some hazardous heavy metals. If paint becomes old, pieces of paint may peel off easily from the surface of its paintwork. Hence it can be attached onto our hands directly. There is a risk that heavy metals from the paint may enter into the children's body if children lick their hands. First, actions of young children were observed to estimate the exposure of heavy metals by contacting the paint surface. It was observed that young children licked their hands and put their fingers into their mouth frequently. Next, smear test was conducted and the effects of the materials as well as the frequency of wiping off the paint were studied to evaluate the quantity of heavy metals attached onto the children's hands or fingers by contacting the paint surface. With the measurement method developed in this study, play sets from a nursery school and playgrounds were examined. The present study indicated that a large amount of Pb was detected, with its maximum value, 4 μg/100cm². Assuming that young children have a habit of licking thier hands or fingers, the quantity of Pb taken was about 3.2 times higher than TDI.

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To observe the leaching property and its change in valence from the soil intentionallypolluted with trivalent antimony (Sb₂O₃). extraction tests were performed with pure water and 1M hydrochloric acid (HCI). After three months from the pollution, extracted fractions of Sb were only 0.1% in pure water and at most 30% in 1M HCI. respectively. Sb concentrations in pure water leachate were two orders of magnitude lower than solubility of Sb₂O₃. These results indicated that the antimony was sorbed by soil rapidly and strongly. changed their form into insoluble. Irrespective of leaching solution and initial soil moisture, Sb (V) was the predominant species in soluble fractions.
After three years. Sb (V) concentration in pure water clearly increased, and soluble fraction increased to 0.5%. The results indicated that aging is one of effective factors on promoting water soluble Sb (V).

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Eentering into the viable but non-cultivable (VBNC) state in a synthetic drinking water (SDW at 50mL, pH 7.0, and 25deg;C), the intracellular resuscitation in Acanthamoeba polyphage (ATCC30462), and survivability of L. pneumophila against exposure to silver (AgNO₃) and/or copper (CuSO₄.5H₂O) reagents were investigated in this study. As the results, L. pneumophila completely lost its cultivability after 30 days incubation in SDW, while it maintained its viability (determined by using flow cytometry (FCM) with SYTO 9 and propidium iodide staining) at a nearly constant level (0.1 log reduction) for 190 days. After 4 days co-incubation with A. polyphage (1×10⁵amoeba/mL), L. pneumophila in VBNC state recovered its cultivability and started to resuscitate, and finally grown to 2.55×10⁷CFU/ml after 7 days. The bacteria that resuscitated and multiplied in amoeba was then exposed to silver (0.1mgAg/L) and/or copper (1.0mgCu/L) reagents. All of planktonic L. pneumophila was inactivated completely within 8 hours after injection of silver or copper, but 7.3×10³ and 5.6×10¹CFU/ml of L. pneumophila residing inside of A. polyphage survived against copper and silver exposure even after 7days incubation, respectively. Consequently, the L. pneumophila residing inside ofA. polyphage showed much higher tolerance than L. pneumophilia in planktonic state against the same doze of silver and/or copper, and this phenomenon was explained by the amoeba interruption to chemisorption of disinfectant onto bacteria residing inside of amoeba.

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In the Mekong watershed, for reducing the infectious risk, the provincial water supply (PWS) system composed of the water treatment plant and the distribution system has been installed in big cities. The village water supply (VWS) system for distributing the groundwater to villagers without any treatments has been also provided. In order to estimate effects of these water supply systems on reducing the infectious risk, two case-studies for evaluating the risk of infectious diseases associated with the drinking water wee conducted. In the case-study in Thailand, the geometric mean of infectious risk in the area with the PWS system was less than one-eighth of that in the area with the VWS system. This result means that the chlorine disinfection of the tap water in the PWS system would contribute to the reduction of infectious risk. In the case-study in Cambodia, the geometric mean of infectious risks in areas with the VWS system was about five times lower than that in the area without access to water supply. Therefore it was expected that the infectious risk could be reduced by the construction of the VWS system in the area without access to water supply.

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The aim of this study is to adapt techniques of molecular biology (real-time reverse transcriptionpolymerase chain reaction (RT-PCR)) to Norovirus detection methods due to the importance of developing a rapid and highly sensitive method for quantitative detection of Norovirus from wastewater. We evaluated the efficiency of the Norovirus detection method for the following processes: 1) Various collection and elution methods, 2) Clarification of sensitivity and detection limit values, 3) Optimization of the collection sample volume suitable for the sewage influent sample, and 4) Optimization of the reverse transcription efficiency of the extracted Norovirus RNA. From the results, for the polyethylene glycol precipitation method, collection and elution methods were investigated and suitable methods for influent, effluent and tertiary effluent were proposed. In the polyethylene glycol precipitation method of inflow sewage, a high collection ratio was observed at the sample volume of about 10 ml. The reverse transcription efficiency was increased by adjusting the addition concentration of primer and RNA. The concentration of the Norovirus cDNA of a necessary 10 copies per reaction tube to obtain a stable value measured by the real-time RT-PCR method was clarified.

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Reduction characteristics of Cr, Cu, Pb and Zn leaching from cement-solidified MSWI fly ash by neutralization were studied. Carbon dioxide was contacted to the cement-solidified material, and the relationship between contacting time and pH changes of the material are described. The test method using phenolphthalein was proposed, in order to get the neutralized condition of material. Furthermore, the tank leaching test was performed to the alkaline material and completely neutralized material, and the leaching flux of Pb, Zn, Cu and Cr from both materials are compared. The leaching flux of Pb, Cr and Cu decreased by neutralization. On the other hand, Zn leaching amount increased because pH of thematerial was considered too low. Keeping the neutralized levels of the cement solidified waste is important to reduce the leaching amount of the heavy metals.

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The changes of chemical states for Pb in virgin and kneaded fly ash with chelating agent were investigated by using XAFS spectroscopy at beam line BL01B1 in SPring-8. The precipitate prepared from a chelating agent of marketing and a lead chloride solution has the same chemical state as the lead chelate complex which prepared from potassium diethyldithiocarbamate and lead chloride solution. Thus it was comfirmed that the chelating agent was able to form a lead chelate complex with Pb²⁺ ion. The chemical form of the lead chelate complex and Pb in kneaded fly ash were the same chemical state by XANES and EXAFS spectra, thus it was verified that the kneading process of fly ash with chelating agent was able to form lead chelate complex. Even when the chemical state of Pb in a fly ash differed, it became clear that the same lead chelate complex generated by kneading processing with a chelating agent.

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An experimental study was conducted to investigate the ability of municipal solid waste bottom ash as a material of Portland cement. Bottom ash contains large amount of chlorine and insoluble chlorine such as Friedel's salt in bottom ash has remained as a problem. If bottom ash is mixed with compost, it is expected that Friedel's salt will be decomposed in a low pH environment, which is caused with acids such as organic acids, the sulfuric acid ion, the nitric acid ion, and the nitrous acid ion which are generated by organic matters decomposed, because Friedel's salt has a high solubility in a low pH less than 11.
In this study, the mixture samples of bottom ash and compost (leaf mould compost, sewage sludge compost, and garbage compost) were tested to clarify influence of organic matters on the elution of chlorine in bottom ash. The pH and the content of chlorine in the mixture samples of bottom ash and compost decreased more than in the samples of bottom ash. The content of chlorine in the mixture samples decreased under 0.2wt.% after 54 weeks. As a result of XRD, main peak of Friedel's salt decreased according to decrease of insoluble chlorine.

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The environmental safety of foaming glass that is made from waste glass was examined. The foaming glass is made by adding silicon carbide to crashed waste glass and being foamed with high temperature. The contents of Pb, As, Cr in a waste carboy and their amount in a leachate from an experimentally made glass were analyzed. As a result, the concentrations of Pb As, and Cr in the waste carboy were 100 (23-190) mg/kg, 11 (4.0-25) mg/kg, and 840 (810-1000) mg/kg, respectively. Green glass had high concentration of all the metals. The concentration of the metals in the leachate was as follows, Pb: 0.15 (<0.01-0.43) mg/l, Cr (IV): 0.11 (<0.05-0.33) mg/l, and As: 1.2 (0.43- 3.1) mg/l.The leaching of Pb from foam glass could be effectively restrained by adding CaSO₄ or Fe₂ (SO₄) ₃ to the raw materials, while the leaching of As could be restrained by adding Ca (OH) ₂ and Fe₂ (SO₄) ₃.

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This study examines waste temperature distribution within the Tokyo Port Landfill where a maximum temperature rise as high as 66deg;C exists. Heat and water transport within a sanitary landfill is modeled and the process of the placement of successive waste layers is considered. Spatial and temporal temperature distributions are simulated to validate the model. The model results with different scenarios of decomposition within the landfill are shown to be in good agreement with observed data. Sensitivity analyses in terms of decomosition shows that active aerobic decomposition at the surface of waste layers during landfilling and successive anaerobic decomposition after the completion of landfilling could result in high waste temperature.

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The characteristics of heavy metals elution from anaerobically digested sewage sludge with oxidizing reagents were investigated by applying hydrogen peroxide, ferric sulfate or their combination to the sludge under acidic conditions. The application of both hydrogen peroxide and ferric sulfate accelerated the elution of Cd, Cu andZn from the sludge and remarkably improved the elution efficiency of Cu at pH2.
Heavy metals in the sludge were fractionated into three organically bound forms associated with water-soluble proteins, fatsoluble ones and extracellular polymers and residual one. The contents of Cu in the organically bound forms associated with fatsoluble proteins and extracellular polymers and the residual form were significantly decreasedafter the metals elution process with ferric sulfate and hydrogen peroxide at pH 2. These results showed a possibility that hydroxyl radicals produced in the Fenton reaction promote the elution of Cu from the sludge.

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Leachate recirculatory semiaerobic landfilling, one of the accelerated stabilization technology of landfill was evaluated on the applicability to coastal reclamation waste disposal based on the water quality of leachate and on the behavior of microorganisms using model reactor. Accelerated degradation/removal of organic carbon and nitrogen was confirmed. Especially both ammonium oxidizing and denitrifying bacteria coexisted in the top layer of the reactor seemed to contribute to accelerated stabilization. Thus, leachate recirculatory semiaerobic landfilling must be a certain technology for accelerated stabilization of coastal reclamation waste disposal, which can stimulate the microorganisms responsible for the degradation/removal of organic carbon and nitrogen. As there are only a few reports on the microbial community structure in landfills or leachate, further accumulation of the data is essential and will show the typical microbial community for the suitable organic compounds decomposition, nitrogen removal, and for the process control.

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A continuous flow post-denitrification (Dephanox type) lab-scale system fed with raw wastewater was operated in order to investigate the effect of the anaerobic solids retention time (anaerobic SRT) on phosphate removal. The presence of an internal settler just after the anaerobic tank enhanced the anaerobic SRT. Additional enhancement was provided by accumulation of solids into the internal settler under extreme operational conditions that seemed to be optimal for nutrients removal. Batch experiments with Dephanox sludge showed that the particulate COD fraction contributed with an additional 50% of phosphate release, thus an additional VFAs production can be inferred. In the case of the Dephanox sludge, the enhanced anaerobic SRT assisted effectively to achieve complete phosphate removal. As reference, the same batch experiments with AO and A₂O sludge from a full scale plant fed with primary effluent were carried out. The results showed that particulate COD fraction did not contribute significantly on the VFAs production. The combination of long SRT and abundant particulate COD apparently promoted fermentative organisms and denitrifying phosphorus accumulating organisms (DN-PAOs) acting in a syntrophic association on phosphorus removal.

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Firstly, phosphate release activity test in which commercial laundry detergents and LAS were added to an actual anaerobic aerobic activated sludge showed the increase of phosphate concentration and PHA content, and subsequent phosphate uptake activity test exhibited the remarkable decrease of phosphate concentration. Therefore, surfactant was likely to be finally accumulated as PHA. Secondly, the adsorption amount of LAS to actual anaerobic aerobic activated sludge in anaerobic tank as well as a daily change in LAS concentration of influent wastewater were examined, so that the adsorption amount of LAS in a lab activated sludge which has never been exposed by any surfactant was adjusted to the actual level by adding detergent including LAS and AE, and sole LAS. Finally, phosphate release test was conducted using the adjusted activated sludge to investigate the effect of sutfactant on acetate uptake by polyphosphate-accumulating organisms. The addition of the detergent hought the increase of acetate uptake rate and the decrease of +ΔP/-ΔAc value. On the other hand, the addition ofthe sole LAS caused respective opposite effects. In other words, LAS decreased acetate uptake rate and its energy efficiency, while AE would increase them.

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Three airlift reactors with sponge-carriers were operated by a stepwise increase of ammonium loading rate at different temperatures, 25, 30, 35°C, to investigate effects of temperature and ammonium concentration on partial nitrification to nitrite. A high ammonium loading rate (1kg NH₄⁺-N·m^-3.·day^-1) caused nitrite accumulation accompanied with remaining ammonium. The ratio of nitrite accumulation to ammonium oxidation strongly correlated with free ammonia more than ammonium concentration or temperature. The free ammonia concentration of 8mg NH₃·L^-1 allowed the almost occurrence of partial nitrification having the ratio of 0.8. The result suggests free ammonia must be a crucial factor to control partial nitrification. Cloningresults of sludge samples showed Nitrospira genus of nitrite-oxidizing bacteria was a predominant microorganism under the complete nitrification condition, while ammonia-oxidizing bacteria predominated under the partial nitrification condition.

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The objective of this research is to make a novel wastewater treatment process activated by a sulfur-redox cycle action of microbe in low temperature conditions. This action is carried out by sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). The reactor system was comprising ofan UASB reactor as pre-treatment and an aerobic downflow hanging sponge (DHS) reactor as post-treatment. As the results of reactor operation, the whole process achieved that over 90% of CODcr removal efficiency, less than 35 mg-CODcr/L (less than 20mg-BOD/L) of final effluent, at 12hr of HRT and at 8°C of UASB reactor temperature. As the result of the effect of temperature methane-producing activity (MPA) and sulfate-reducing activity (SRA) of sludge retained in the UASB reactor, below the 25°C condition, SRA was greater than MPA from acetate and H₂/CO₂ as test substrate. And that MPA was all but destitute at 15°C, SRA was certain despite at 5°C. The proposed sulfur-redox action process was considered as an applicable process for low strength wastewater treatment in low temperature conditions.

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The wastewater treatment system of an industrial park where there are major industries that significantly contribute to the local economy was studied. The cost of wastewater treatment affects not only economies of the major industries themselves in the industrial park but also other economic activities in the region. In this study, a local economic model that includes the major industries which are fishery firms, other firms and households was constructed. The effect of the cost of wastewater treatment of the industrial park on local economy was examined by using the economic model. Three possibilities, namely centralized treatment, in which industrial wastewater is collected by pipeline and treated at a central treatment plant, discharge into public sewerage and treatment by each firm, were evaluated. The centralized treatment was found to be the best option from economical as well as environmental point of view.

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Recently, the photocatalyst is attracting attention in various fields. However, there are few studies that investigated guantitatively capacity or effect of photocatalyst. The evaluation method of photocatalytic reaction has not been established. The organic matter decomposition experiment was performed in this study, using a batch type reactor as experimental reactor. The quartz beads coated with thin film of TiO₂ as photocatalyst were used. The light source used in the experiment was the black light (BL, 15W). Methylene blue was used as representative of organic matter. From experimental results, the reaction mechanisms of the organic matter decomposition by photocatalytic reaction could be expressed by the model equation, and the rate constant of the used photocatalyst was able to be calculated concretely.

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This study investigates the water quality purification properties of three functional foamed waste glasses (foamed waste glass (FWG), zeolitized FWG and Mg-type FWG) through the batch type adsorption test and the continuous flow test. As a result, it can be proved that these functional foamed waste glasses have high properties of water purification in the removal of SS, BOD, nutrient and heavy metal. Moreover, each of these glasses has its own function in waste removal property, and can be applied to water quality purification systems in rivers, pond and reservoirs.

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Experiments were executed to make clear the effectiveness of crushed roof tiles as the packing material of slant soil layer method. The following conclusions were obtained from the results. 1) Aerobic reaction could happen more actively in the case using crushed roof tiles than in the case using Akadama soil or Kanuma soil. 2) The reaction could happen at about 10 degrees Celsius. 3) The removal of ammoniac nitrogen and phosphoric acid phosphorous was mainly caused by absorption. 4) The nitrogen and phosphorous removal ability of Akadama soil and Kanuma soil was superior to that of crushed roof tiles. 5) A high denitrification ability of a slant soil laiyer could be obtained by adjusting the particle size of crushed roof tiles. Therefore, it is possible to make an advanced sewage treatment slant soil layer system by combining some types of slant soil layers.

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A new process, in which subcritical water process was applied to hydrolyze and solubilize the excess sludge whereafter phosphorus and methane were recovered by MAP and UASB method respectively, was developed by our research group. It was confirmed feasible that phosphorus and methane could be recovered by MAP and UASB process respectively from the solubilized excess sludge. However, there was no information that the difference in the recovery rates of phosphate and methane had occurred by changing the sequence of MAP and UASB process. In this study, the optimum process of phosphorus and methane recovering with MAP and UASB method from solubilized excess sludge was investigated. According to the experiments results, the optimum resource recovery process were in the sequence of UASB and then MAP method.

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Removal of phosphate in wastewater is very important because it causes the eutrophication of the lake or pond. On the other hand, phosphate recovery from sewage and sludge treatment systems is particularly important because it is a limited resource and a large proportion of the phosphate currently used in Japan must be imported. Therefore, we have been experimentally evaluating phosphate and coagulant recovery methods from pre-coagulated sludge with NaHS.
In this study, we experimentally investigated the influence of the coagulated sludge characteristics with ferric chloride on its phosphate and coagulant recovery process. The phosphate extraction and recovery from pre-coagulated sludge with various amount of FeCl₃, the iron dissolution using HCl and the oxidation with H₂O₂ experiments were conducted.
As the result of phosphorus extraction experiment, we found that the increase of FeCl₃ dose led to high phosphorus extraction ratio because of the increase of FePO₄ in sludge and not extracted phosphorus could exist with Al, Ca and organic matter. In phosphorus recovery experiment, we could obtain good recovered materials which contained 15% of phosphorus and little heavy metals. And as the result of coagulant recovery experiment, recovered coagulant is as effective as commercial FeCl₃.

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In this work, we used modeling by ATP concentration of sludge as an indicator in order to classify sludge converted into substrate by ATP analysis of sludge, then comparing the examination results with those obtained by simulation of excess sludge in the activated sludge process.
As a result:(1) By assuming that extinction sludge is not detected by ATP, converted sludge was classified into activated sludge, extinction sludge and soluble matter. Then a “Conversion to substrate and biodegradation of sludge” model was developed using an indicator from ATP analysis of sludge.(2) The concentration ratio of activated sludge and extinction sludge in suspended matter was clarified by analyzing the ATP concentration of sludge that was converted to substrate by an ultrasonic processing reactor. The concentration ratios of the three components in converted sludge were estimated by adding the soluble matter concentration.(3) Simulated values obtained from the model based on applying the concentration ratios of converted sludge following ultrasonication were consistent with the results obtained from continuous experimentation. Therefore, the “Conversion to substrate and biodegradation of sludge” model is considered available for analysis of activated sludge process without excess sludge production.(4) On simulation of this model by ultrasonication, the reduction ratio, water quality of effluent and ratio of extinction sludge in the aeration tank could be estimated by setting parameters of MLSS, the concentration ratio of the converted ratio under the various operation conditions.

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Fundamental performance and effective operation of the sludge solubilization treatment by the simultaneous use of ultrasonic and electrolytic processes was investigated experimentally. A lab-scale diaphragm cell irradiated with ultrasound at a constant oscillating frequency of 20kHz was used as a reactor. The batch experiments were carried out under different electric outputs of the ultrasonic generator, electric currents for the electrolysis and initial SS concentrations. The simultaneous use of ultrasonic and electrolytic processes accelerated soluble COD generation and reduced the specific energy consumption, compared to sonication alone. The pH adjustment of the sludge to a moderate alkaline condition as a pretreatment further contributed to the improvement of the solubilization performance in the simultaneous use. Such solubilization treatment effectively performed under the conditions below 400W/L of the ultrasonic density and below 30g/L of the initial sludge concentration within the experimental range in this investigation. The soluble components in the solubilized sludge had higher a content of readily biodegradable substrates than that by the sonication alone.

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