Field surveys were conducted to obtain fundamental information on the removal of endocrine disrupting chemicals (EDCs) and pharmaceutical residues (PRs) with conventional water quality parameters in wastewater treatment plants (WWTPs) in Thailand. Oxidation ponds and constructed wetlands were focused on because these systems are adapted in about 60% of municipalities. In the field surveys, water samples including the influent and effluent as well as water at the middle part of plants were taken from 6 WWTPs receiving municipal sewage or hospital wastewater. Totally 11 EDCs and PRs which have been detected frequently in public water body in Thailand were measured by LC-MS/MS. It was found that the EDCs and PRs were present in the range of 0.001 to 10² μg/L and 0.001 to 1 μg/L in the influents and effluents of WWTPs, respectively. Every pollutant was removed by WWTPs in different manner. More than 80% of naproxen and 70% of estrone were removed, while those of other pollutants such as p-acetaminophen, ibuprofen, DEET, and gemfibrozil were different among WWTPs. It was shown that oxidation ponds and constructed wetlands are effective to remove EDCs and PRs concurrently. However, a further study will be needed to evaluate precise removal performances and relations to design and operation parameters.

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Blast furnace, converter and electric arc furnace (EAF) processes have produced iron and steel slag as byproducts. In terms of resource utilization, the EAF process making steel from scrap metals is superior to other steelmaking processes from iron ores or pig iron. Although all blast furnace slags can be completely recycled for use of steelmaking slag base and cement aggregate, parts of EAF slag ultimately end up in landfill sites. A laboratory-scale investigation was performed to develop novel applications of EAF slag in aquatic environments. To examine chemical properties of the EAF slag and the effects on organisms, strict experimental conditions were designed to elute the metal components of the slag using HCl based on JIS K 0058-1. Analysis of the chemical properties of the slag by ICP-AES and ICP-MS showed that the metal effluents from the slag were less than the concentrations defined by the environmental quality standards. Other analysis using a pH meter showed that the eluate in acidic freshwaters drastically changed their pH values from acidic to neutral. Regarding the effects of the slag on organisms, the eluate in acidic conditions notably induced proliferation of phytoplankton rather than cytotoxicity by improving the pH condition.

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A composting toilet, using sawdust as a matrix, has the potential to trap pathogens that might occasionally be contained in human feces. High temperature, low water content and high pH conditions are effective in reducing the pathogen content. However, it is not clear which parts or functions of pathogens are damaged under these conditions. Therefore, the present study investigates the inactivation mechanisms of pathogenic bacteria in a composting toilet, focusing on which parts and/or functions were damaged. Escherichia coli (E. coli) was used as a model of pathogenic bacteria, and its inactivation mechanisms were estimated by multiple detection methods. Differences in detection principles among the 3 types of growth media and the polymerase chain reaction method (PCR) were used as a method to investigate the damages caused by each. In addition, damage to the outer membrane was distinguished by using a propidium monoazide (PMA) treatment. The results indicated that E. coli was rapidly inactivated due to metabolic function and slight outer membrane damage under high pH conditions. In dry conditions, E. coli was inactivated by damage to metabolic function and slight outer membrane damage. High temperature treatment damaged the outer membranes effectively, and inactivated them rapidly.

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Effect of the addition of chelator on the acute toxicity of heavy metal ions to freshwater organisms was examined. The Cu(II) complexation ability estimated in this study was in the order: EDTA > NTA > IDA > citric acid, aspartic acid > humic acid, natural organic matters from lignite. Then, the acute toxicity of several heavy metal ions (Cu(II), Zn(II), Pb(II), Cd(II), and As(V)) were evaluated using Daphnia magna in the absence or presence of chelators. The acute toxicity for cationic metal ions greatly decreased when artificial chelators, such as ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), were added in the test solution. However, the correlation between toxicity reduction abilities for Cu(II) and the metal complexation ability of these chelators was poor. In addition, the Cu(II) uptake was decreased when EDTA and NTA were added in the test solution. A single logarithmic linearity between the Cu(II) toxicity (EC₅₀) for D. magna and Cu(II) uptake was observed. It is concluded that the addition of chelators affects the complexation ability for heavy metals and metal uptake into the organism, and also the heavy metal toxicity reduction is directly dependent on the uptake of the metal.

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Suspended sediment load in relatively smaller rivers draining agricultural areas was monitored and the suspended sediment rating curve was established using two regression analysis approaches—applying data stratification to ameliorate the prediction model equations. The sediment load data were observed for forty-five months in three rivers in an agricultural area in southern Ehime Prefecture, Japan. The data were analyzed using the power function and detransformed logarithmic function regression methods, while testing and elucidating the appropriateness and efficiency of these regression methods. Results showed that data stratification significantly improved the discharge-sediment load correlation and reduced curve-fitting errors, thereby, improving the efficiency of the derived model equation. Moreover, data stratification was found necessary in the analysis to account for nil sediment concentration observed during low flow periods. Between the two regression analysis methods, power function regression appears to have better predictive capability and, thus, more appropriate to smaller rivers. Specifically, as compared to the detransformed logarithmic function regression, power function yields models with significantly higher correlation and efficiency coefficients, as well as predicted sediment load closer to the observed sediment load.

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The aims of the present study are to evaluate the effects of the photocatalytic decomposition of toxic atmospheric substances with TiO₂ in the actual atmospheric environment. Titanium dioxide loaded glass simulates the function of a sound-proof wall with photocatalysis, which was set on the roadside of a highway. The decomposition of attached substances on the glass was measured in warm and cold periods for polycyclic aromatic hydrocarbons (PAHs) and toxicity. From the measurements of the concentration decrease in PAHs artificially attached to the glass, a significant toxicity decrease by TiO₂ photocatalytic decomposition was observed. For the naturally attached toxic substances in the roadside, on the other hand, the decrease was observed less than that of artificial condition. Still, significant decreases were observed for PAHs and Ah-immunoassay in warm periods. For the toxicity of V. fischeri, on the other hand, no significant decrease was observed both in cold and warm periods.

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Exposure to chemicals and their transformation products is important for evaluating environmental risk. In this study, the analytical method for both pesticides and pesticide transformation products (PTP) in water environments was developed. Eleven pesticides were selected based on the amount of their use in Kanagawa, Japan. According to previous literature research for PTP which have been found in hydrolysis and/or photolysis, 77 PTP could be enumerated. Among them, 30 commercially available PTP and their 11 parent pesticides were tested in this study. The detection sensitivity for pesticides and PTP was evaluated using GC-MS and LC-MS/MS. Using GC-MS, 31 compounds could be detected with a limit of quantification (LOQ) of 10 - 50 ng/mL. To achieve detection of GC-MS-unfavorable compounds and more sensitive detection by LC-MS/MS, two atmospheric pressure ionization methods (electron spray ionization (ESI) and atmospheric pressure chemical ionization (APCI)) were assessed. Comparison of the LOQs demonstrated that the ESI method achieved more sensitive analysis than the APCI method. Also, LC-ESI-MS/MS showed higher sensitivity (< 1 ng/mL) for the 11 compounds. As a result, except for 3 PTP, all pesticides and PTP were detected by the method developed. This analytical method can be applied to determine pesticides and PTP in environmental water samples.

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Decentralized water reclamation and reuse has been proposed in peri-urban areas of Bangkok where rapid urbanization and industrialization have been causing increases in water demand and water shortages. It was suggested that domestic greywater from laundry and bath and shower wastewater containing low BOD are acceptable for reclamation and reuse by the residents in the area. Although the water contains high concentrations of surfactants, little is about known on their actual discharge loadings in Thailand. Therefore, the MBAS and LAS contents of commercial detergents, including liquid soap, shampoo, liquid dish soap and powdered laundry soap were measured. The daily MBAS and LAS discharge loadings per person were estimated to be 4.44 g/p/d and 3.08 g/p/d, respectively by using daily usage of the detergents and their share factors obtained by a questionnaire survey in the previous study. Powdered laundry detergent contributed the most to MBAS loadings, while liquid dish soap, shampoo and liquid soap were the next. The LAS loadings were primarily derived from liquid dish soap and powdered laundry detergent. The decrease in the surfactant concentrations measured in drainages and canals suggested that biological treatment was applicable for the reclamation of greywater containing detergents.

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The organophosphate pesticide fenitrothion and its degradation product 3-methyl-4-nitrophenol (3M4NP), which possesses greater mutagen formation potential (MFP) than fenitrothion, were monitored. A total of 109 samples were collected from 41 sites of 12 rivers in the Tokyo metropolitan area and 71 samples were collected from 4 sites of 2 streams close to paddy fields in Kanagawa, Japan. The concentrations of fenitrothion and 3M4NP were determined by GC/MS with selected ion monitoring after solid-phase extraction and derivatization of 3M4NP with N, O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA). Both fenitrothion and 3M4NP were below 1 μg/L (0 - 0.083 μg/L of fenitrothion and 0 - 0.156 μg/L of 3M4NP) in the river water samples, whereas fenitrothion and 3M4NP reached 0.16 and 1.6 μg/L, respectively, in the stream water samples. Seasonal and areal fluctuations were also observed in the streams. Nevertheless, the maximum concentration of 3M4NP appeared in late May at all sites. Furthermore, among the samples in which fenitrothion and/or 3M4NP were detected, 3M4NP largely contributed to the potential in 56% and 67% of the river and stream samples, respectively. These results strongly support the need for simultaneous monitoring of various pesticides and their degradation products, identification of degradation products and their MFP, and characterization of their behavior in water purification processes.

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Fenitrothion [O, O-dimethyl O-(3-methyl-4-nitrophenyl)phosphorothioate], a typical organophosphorus pesticide, is widely used as an insecticide in Japan. In this study, 3-methyl-4-nitrophenol (3M4NP), which is a typical hydrolysate of fenitrothion, was focused as a possible mutagen precursor because it is reported as a common contaminant in raw water for water works, and is capable of forming mutagens when it is chlorinated in water works. In order to examine molecular formulae of mutagens produced from 3M4NP, a chlorinated 3M4NP sample was analyzed with a high-resolution LC/MS. Several peaks were found in a base peak chromatogram. A peak of m/z 215.971 was focused to be analyzed, suggesting a formation of C₇H₄O₅NCl (mass error = 0.397 mmu or 1.837 ppm). To examine the chemical structure of the found substance, MS² experiments were conducted with a collision induced disassociation technique. Four product ions: m/z 198.9679, 187.9757, 170.9731 and 136.0043 which can be attributed to losses of OH, CO, COOH and Cl functional groups were observed. From these fragment ions and the structure of 3M4NP, the substance was extrapolated to be chloro-5-hydroxy-2-nitrobenzoic acid (C5H2NB). The mutagen formation potential (MFP) of 5-hydroxy-2-nitrobenzoic acid, which is considered to be a precursor of C5H2NB, was tested and the MFP of 3,400 net rev./μmol was observed.

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Low pressure reverse osmosis (LPRO) membrane filtration has emerged as the best alternative to ordinary reverse osmosis (RO) membrane filtration due to very low operating pressure involved with the former resulting in low cost. However, behaviors of perfluorinated compounds (PFCs) with LPRO membrane filtration are not known since the compounds as water/wastewater contaminants have only a very short history. Therefore, adsorption and diffusion behaviors of selected perfluoroalkyl carboxylate (PFAC) and perfluoroalkyl sulfonate (PFAS) compounds with a tight and a loose LPRO membranes were tested in laboratory experiments. Distribution coefficient (logK_mw) and diffusion coefficient (D_p) values for the compounds were experimentally determined for the first time. The D_p values were about three orders of magnitude larger than those for pharmaceutical and endocrine disrupting compounds. The compounds exhibited similar behaviors to those of pharmaceutical and endocrine disrupting chemicals reported earlier. Adsorption of PFCs to membranes was directly correlated to molecular weight (MW) and carbon-chain length, while their diffusion through membrane pores showed inverse correlations with the parameters. Similarly, their rejections were directly correlated to their logK_mw values and MW. However, significance of carbon-chain length on diffusion was not well understood, and hence further investigations should be devoted to elucidate on the point.

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The concentration variations of dissolved metal ions and their buffering effect in an acidified river were investigated by analyzing the data collected through a long-term field investigation and an intensive field investigation. The field investigations targeted Matsukawa River in Japan, which is acidified by the inflow of acid mine drainage. In periods of rainfall and snowmelt, Al, Mn, Fe, Cu, and Zn ions exhibited different decreasing trends than did alkali and alkaline earth metal ions and sulfate. These findings suggested that the decreases in Al, Mn, Fe, Cu, and Zn ion concentration were attributable not only to dilution by the inflow of rainwater and snowmelt but also to the hydrolysis of Al. Additionally, the mineral phases of Al in this acidified river were analyzed by using the geochemical modeling software (PHREEQC). From the results, dissolved Al ions acted as a buffer from pH 4 to 6, and the basaluminite (Al₄(SO₄)(OH)₁₀) as the dominant chemical species, mainly controlled the solubility of Al from pH 4 to 6.

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