Comprehensive Study on Enteric Viruses and Indicators in Surface Water in Kyoto,Japan, During 2014–2015 Season

Certain enteric viruses that are present in the water environment are potential risk factors of waterborne infections. To better understand the impact of viruses in water, both enteric viruses and their potential indicators should be comparatively investigated. In this study, occurrences of GI- and GII-noroviruses (NoVs), sapovirus (SaV), rotavirus (RoV), Aichi virus 1 (AiV-1), enterovirus (EV), and pepper mild mottle virus (PMMoV) were quantitatively determined in surface water samples in Japan. Additionally, the genotype distribution of GI- and GII-NoVs was determined using a next-generation amplicon sequencing. PMMoV was the most abundant virus regardless of season and location, indicating its usefulness as an indicator for the viral contamination of water. Other potential indicators, AiV and EV, were less abundant than GII-NoV. Viruses other than PMMoV showed seasonality, i.e., EV and other viruses (NoVs, SaV, RoV, and AiV-1) became prevalent during summer and winter, respectively. SaV showed a relatively high abundance at a location that was affected by untreated wastewater. Regarding NoV genotypes, GI.1, GI.2, GI.4, GI.5, GI.6, GII.3, GII.4, GII.6, and GII.17 were found from the surface water samples. GII.4 and GII.17 seemed to have contributed to the high abundance of GII-NoV in the samples. Interestingly, GII.17 strains became prevalent in the water samples before becoming prevalent among gastroenteritis patients in Japan. These findings provide further insights into the properties of viruses as contaminants in the water environment.     

Measuring the Effects of a Flood Control Project: Hedonic Land Price Approach

This article aims to measure the effects of a flood control project planned for the Chitose River Basin in Hokkaido Prefecture, Japan, using hedonic land price functions. In these functions, "annual expected depth of flood water" is introduced as an explanatory variable to represent the effect of the flood control project. Comparing the approach with the method of "the economic analysis of flood control projects", which has been a conventional evaluation method widely used in Japan, the efficiency and limitations of our approach are discussed.     

Voltammetric response of ferroceneboronic acid to diol and phenolic compounds as possible pollutants

A voltammetric determination of possible organic pollutants such as diol and phenolic compounds in water was studied using ferroceneboronic acid (FBA) as a redox-active marker. A cyclic voltammogram of FBA exhibited a pair of oxidation and reduction peaks at 230 and 170 mV at pH 7.0, respectively, while another pair of redox peaks was observed in the presence of diol or phenolic compounds tested. The results were rationalized based on the formation of boronate esters of FBA with the added compounds. The changes in the redox peak currents were dependent on the concentration of the additives, suggesting a usefulness of FBA in the electrochemical determination of these compounds in water.     

Bioelectrochemical conversion of urea to nitrogen using aminated carbon electrode

Urea decomposes to ammonia and carbon dioxide via carbamic acid, and amine groups can be introduced to the glassy carbon electrode surface during the electrode oxidation of carbamic acid. This modified carbon electrode has excellent catalytic activity of the oxidation of carbamic acid, and can be used to electrooxidize urea by combining urease reaction and electrode oxidation. We found that nitrogen gas is finally produced by the carbamic acid produced from urea. The production of nitrogen was confirmed by gas chromatography-mass spectrometry, and fragment pattern of hydrazine was also detected in the electrolyzed solution of urea. We intend to describe new electrochemical conversion system of urea to harmless nitrogen gas. The electrode oxidation current of urea was decreased by addition of radical trapping agent such as DMPO (5,5-dimethyl-1-pyrroline N-oxide), and this fact suggests that carbamic acid radical couples to form nitrogen-nitrogen bond, and this dimer is oxidized to nitrogen. The electrode oxidation current of urea became larger when oxygen was removed. This fact indicates that the intermediate species (probably hydrazine) produced by the electrolysis is oxidized by not only electrode reaction but also oxygen.     

Study on polychlorinated dibenzo‐p‐dioxins and dibenzofurans in rivers and estuaries in Osaka Bay in Japan

In order to search the source of polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) in blue mussel in Osaka bay, sediments from Osaka bay and from rivers running near an urban municipal incinerator were analysed for PCDDs, PCDFs and PCBs. The river and estuary sediments were all found to be contaminated with PCDDs at average levels of 9.8 and 12ppb on the dry basis, PCDFs of 7.8 and 5.1 ppb, and PCBs of 1600 and 1300ppb, respectively. The two sediments contained similar profiles of specific isomers and congeners of PCDDs and PCDFs with each other. In addition, there was observed positive close correlations between PCDD and PCDF levels in the two specimens as well as fly ash from urban municipal incinerators. These allow the conclusion that the main source of the two chemicals in Osaka bay is fly ash from waste incineration.     

石灰投加与搅拌对生态厕所的灭菌效果

以发展中国家农村地区的卫生条件改善为目的,开展了简易生态厕所的粪便堆肥处理实验。在投加石灰作为抑菌剂的条件下,研究了搅拌混合对杀灭致病微生物的影响,以及使堆肥终产物达到可接受风险值所需的最佳搅拌条件。实验确定了石灰的投加量,并应用Beta-Possion模型对堆肥处置过程中致病微生物对暴露人群的健康风险进行评价,从而从健康风险控制的角度确定了最佳的搅拌次数。研究结果表明,石灰投加量约占堆肥干重1.5%,手动搅拌50次,经搅拌后放置12 h能达到可接受的风险值(3.2×10-5)。     

Fate estimation of estrogenic substances in an urban river by flux calculation.

This study investigated the fate of estrogenic substances in an urban river receiving discharge from wastewater treatment plants (WTPs) by flux calculation, focusing on the middle reaches of the Tama River in Tokyo, which is one of the most urbanized rivers in Japan. The level of estrogenic activity flux was almost negligibly small at the upstream station. The level was considerably raised after inflows from the WTPs and then the level declined in the lower reaches of the river. When contributions of estrogenic substances to estrogenic activity were estimated, estrone (E1) was the primary contributor to the total estrogenic activity in all the sampling stations, followed by estradiol (E2). The contribution of nonylphenol to estrogenic activity was small. The E1 and E2 accounted for approximately 90% or more of estrogenic activity in the Tama River. As for the total fluxes of the estrogenic substances in the study area in the Tama River, the proportion of flux associated with WTP discharge was approximately 100% of the total fluxes, and the effects of the tributaries flowing into the river were almost negligible. When the reduction ratios of estrogenic activity were calculated by the flux, the ratios were found to increase toward the lower reaches of the river. Similar changes were observed for E1. Meanwhile, the change of reduction ratios for E2 was different from that observed for estrogenic activity.     

Darkened Xenopus tadpoles appeared with neurochemical agents

Skin darkened tadpoles sometimes appear spontaneously. Darkened was artificially induced in Xenopus larvae by yohimbine or chlorpromazine. These phenomena look like that are seen at pinealectomized or hypothalamus separated Xenopus larva. In this experiment, such a morphological color changed Xenopus larva is suggested by cause of inhibition of alpha2-adrenargic receptor or dopamine receptor from gastrula stages.     

Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from various carbon sources by batch-fed cultures ofAlcaligenes eutrophus

Copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) were produced at 30°C from various carbon sources byAlcaligenes eutrophus under batch-fed growth conditions. The production of P(3HB-co-3HV) from butyric and pentanoic acids was effective under nitrogenlimited conditions, and the conversion of carbon sources into copolyester was as high as 56 wt% at a C/N molar ratio of 40. In contrast, under excess-nitrogen conditions (C/N<10), cell growth was good, while P(3HB-co-3HV) production was partially inhibited. The production of P(3HB-co-3HV) from fructose and propionic acid was almost completely inhibited under excess-nitrogen conditions.     

Development of extraction method of pharmaceuticals and their occurrences found in Japanese wastewater treatment plants

In this study, occurrence of 66 PPCPs (pharmaceuticals and personal care products) in liquid and solid phases of sewage sludge was elucidated. The extraction methods for the PPCPs from sludge were newly developed employing Pressurized Liquid Extraction (PLE) and Ultrasonic Solvent Extraction (USE). As an appropriate method, PLE using water (pH2), PLE using methanol (pH4), and USE using mixture of methanol and water (1/9,v/v, pH11) was found most effective because total recovery of most of the PPCPs indicated 40 to 130%. The developed extraction method with previously developed method for liquid phase analysis was applied to field survey at wastewater treatment plants (WWTPs) in Japan. 56 compounds were detected from the primary sludge and 61 compounds were detected from the excess sludge. The concentration was ranged between several ng/g and several μg/g. Solid-water distribution coefficient (Log K_d) ranged between 0.9 L/kg (Caffeine) and 3.7 L/kg (Levofloxacin) for primary sludge and between 1.4 L/kg (Sulpirid) and 4.3 L/kg (Mefenamic acid) for excess sludge.