Removal of PCDD/Fs from contaminated sediment and released effluent gas by charcoal in a proposed cost-effective thermal treatment process

A novel cost-effective thermal treatment technology has been proposed for the removal of PCDD/Fs from contaminated sediment and released effluent gas using charcoal as both an adsorbent and a thermal source. When a reactor was used for thermal treatment, the PCDD/Fs removal efficiency exceeded 98% from the sediment at the three different air superficial velocities employed in this study. The total PCDD/F international toxic equivalent (I-TEQ) contents, both in the treated sediments and effluent gas, were below the Japanese emission standard limit. Analysis of the PCDD/F contents in different fractions showed that large quantities of PCDDs but not PCDFs were evaporated from the sediment and adsorbed in the moist sediment column. This difference was attributed to the formation of PCDDs from pentachlorophenol (PCP) during the cooling process following the thermal treatment process in the reactor. This proposed thermal process provides a promising alternative to the conventional methods.     

Contamination status and accumulation features of persistent organochlorines in pet dogs and cats from Japan

Concentrations of persistent organochlorines (OCs) such as polychlorinated dibenzo-p-dioxin (PCDDs), dibenzofurans (PCDFs), biphenyls, dichlorodiphenyltrichloroethane and their metabolites (DDTs), hexachlorocyclohexane isomers, hexachlorobenzene, and chlordane compounds were determined in genital organs of pet dogs and cats and pet foods from Japan. Levels of OCs in dogs were relatively lower than those in cats, while residue levels in their diets were almost similar, implying that accumulation and elimination mechanisms of these contaminants are different between dogs and cats. When bioconcentration factors (BCFs) were estimated from concentrations of OCs in dogs, cats, and their diets, BCFs of all the OCs except PCDD/DFs exceeded 1.0 in cats. On the other hand, in all the dogs, BCFs of DDTs were below 1.0, suggesting that dogs do not bioconcentrate DDTs. Furthermore, BCFs of all the OCs except PCDD/DFs in dogs were notably lower than those in cats, suggesting that dogs have higher metabolic and elimination capacity for these contaminants than cats. When residue levels of OCs in livers, adipose tissue, and genital organs of two pet dogs were examined, hepatic sequestration of PCDD/DFs and oxychlordane was observed.     

基于2H&18O和水化学成分的永定河流域地下水循环特征解析

运用环境同位素和水化学成分作为水循环研究的示踪剂, 揭示了永定河流域中下游地下水 循环特征。通过现场调查并对浅层和深层地下水采样, 进行室内水化学和氢氧同位素组成测定, 分 析了流域内深层和浅层地下水的氢氧同位素和水化学组成的空间分布规律和演化趋势, 揭示了流 域地下水循环特征。结果表明, 降水是山前地下水的主要补给源, 地下水在接受降水的补给后经过 了不同程度的蒸发作用, 山区受蒸发影响较小, 平原区较大, 尤其是平原区浅层地下水呈现出强烈 的蒸发浓缩作用; 水化学特征表现为自西部山区到山前平原至滨海平原, 自浅层到深层, 地下水的 矿化度逐渐升高; 平原区浅层和深层地下水含水层之间存在明显的越流补给现象; 沿海地区未发现 海水入侵现象。     

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.