有机氯农药硫丹的生殖毒性及其机制研究进展

硫丹作为一种广谱有机氯农药,在农业区域周边的土壤和水体中都存在较高残留,2011年被斯德哥尔摩公约列入持久性有机污染物(POPs)名单。硫丹已被证实对神经系统、心血管系统、肝、肾等具有毒性作用,关于其生殖毒性的研究很多,但潜在机制尚不完全清楚。本文总结了硫丹导致的不同动物的生殖毒性,并从生殖器官和生殖细胞损伤、氧化应激以及DNA损伤、生殖细胞周期阻滞及细胞凋亡等方面,对近年来硫丹生殖毒性及其作用机制研究进展进行综述,并对其中存在的问题进行讨论,以期有助于深入了解硫丹的毒性效应。     

不同测试方法评估48%毒死蜱乳油对玉米田施药者的人体暴露风险

本研究选取3种不同暴露环境,分别为玉米株高达到施药者膝盖左右(暴露环境1)、达到施药者腰部左右(暴露环境2)和高于施药者身高(暴露环境3),采用手动背负式喷雾器,在这3种暴露环境中施喷48%毒死蜱乳油(EC,稀释500倍),通过贴片法和全身整体测试法(whole body dosimetry,WBD)分析了施药者农药皮肤暴露量(dermal exposure,DE)。依据试验结果,发现在暴露环境1和2中,2种测试方法的农药潜在皮肤暴露量(potential dermal exposure,PDE)无显著性差异,但在暴露环境3中,2种测试方法的PDE之间存在显著性差异(LSD0.05=57.9);对施药者的主要暴露部位进行分析,发现在暴露环境1和暴露环境2中2种测试方法的暴露部位类似,但在暴露环境3中显示,贴片法为手部,全身测试法为上半身(头、颈、前胸、后背及手臂)。使用全身测试法测定PDE同时测定直接皮肤暴露量(actual dermal exposure,ADE),并利用ADE和PDE计算外穿防护服(运动服)渗透率的结果,3种暴露环境分别为4.69%、5.19%和5.54%,比通常假设的防护服或工作服的10%渗透率小。     

相变溶剂捕集CO2技术的研究进展

化学溶剂吸收法是目前应用最广泛的燃烧后CO₂捕集技术。介绍了化学溶剂吸收法的基本原理,综述了化学溶剂吸收法的研究现状,比较分析了几种常用CO₂吸收剂的优缺点。重点阐述了两类新型相变吸收剂（液-液相变溶剂和液-固相变溶剂）的研究进展。指出：新型相变溶剂是理想的CO₂吸收剂,用其捕集CO₂可有效降低吸收剂的再生能耗;相变溶剂吸收CO₂的传质反应动力学以及不同类型相变溶剂的挥发和降解特性应作为今后该领域的研究重点。     

钯负载泡沫镍电极电化学还原水中三氯乙酸

采用非电沉积法制备了钯负载泡沫镍电极,运用SEM技术对其进行了表征,并以其阴极、铂丝为阳极进行了电化学还原三氯乙酸的研究,考察了工艺条件对三氯乙酸降解效果的影响,并对反应动力学和反应机理和进行了探讨。结果表明:钯负载泡沫镍电极具有较高的比表面积和良好的储氢性能;以20 mmol/L硫酸钠为电解质,在电解温度为20℃、钯负载量为4.5 mg/cm~2的条件下恒流(10 mA)电解240 min,三氯乙酸降解率达99.76%,氯原子脱除率达73.86%;三氯乙酸的电化学还原反应过程以及三氯乙酸上未脱除氯原子浓度的变化均符合拟一级反应动力学方程;三氯乙酸在电化学还原过程中逐个脱除氯原子。     

Photolytic degradation of decabromodiphenyl ethane (DBDPE)

The photolytic degradation of decabromodiphenyl ethane (DBDPE), an alternative flame retardant to decabromodiphenyl ether, was investigated in a variety of matrixes (n-hexane, tetrahydrofuran, methanol/water, humic acid/water, and silica gel) by irradiation under ultraviolet light and in n-hexane under natural light. Photolytic degradation of DBDPE occurs in all the matrixes investigated within the irradiation period (<320 min). The degradation experiments showed varied reaction rates, dependent on the matrixes, with increasing half-lives (t_1/2) in the order of tetrahydrofuran (t_1/2 = 6.0 min) > n-hexane (t_1/2 = 16.6 min) > humic acid/water (30 < t_1/2 < 60) > silica gel (t_1/2 = 75.9 min) > methanol/water (t_1/2 > 240 min). The reaction in tetrahydrofuran, n-hexane, and silica gel matrixes can be described by the pseudo first order kinetics. Nevertheless, the matrixes have little effect on the degradation product distributions of DBDPE. A numbers of debrominated intermediates were identified. The degradation involves the initial formation of nona-BDPEs and the subsequent decomposition of these congeners to lower brominated congeners (octa- and hepta-BDPEs) within the irradiation time. To our knowledge, the present work is the first attempt to investigate the photolytic degradation kinetics and the identification of intermediates, as well as the degradation mechanism, during the degradation of DBDPE. Further research is needed to understand the photolytic degradation pattern of DBDPE in the natural environment.     

Derivation of site-specific surface water quality criteria for the protection of aquatic ecosystems near a Korean military training facility

This study suggested the first Korean site-specific ecological surface water quality criteria for the protection of ecosystems near an artillery range at a Korean military training facility. Surface water quality (SWQ) criteria in Korea address human health protection but do not encompass ecological criteria such as limits for metals and explosives. The first objective of this study was to derive site-specific SWQ criteria for the protection of aquatic ecosystems in Hantan River, Korea. The second objective was to establish discharge criteria for the artillery range to protect the aquatic ecosystems of Hantan River. In this study, we first identified aquatic organisms living in the Hantan River, including fishes, reptiles, invertebrates, phytoplankton, zooplankton, and amphibians. Second, we collected ecotoxicity data for these aquatic organisms and constructed an ecotoxicity database for Cd, Cu, Zn, TNT, and RDX. This study determined the ecological maximum permissible concentrations for metals and explosives based on the ecotoxicity database and suggested ecological surface water quality criteria for the Hantan River by considering analytical detection limits. Discharge limit criteria for the shooting range were determined based on the ecological surface water quality criteria suggested for Hantan River with further consideration of the dilution of the contaminants discharged into the river.     

Water quality guidelines for chemicals: learning lessons to deliver meaningful environmental metrics

Many jurisdictions around the globe have well-developed regulatory frameworks for the derivation and implementation of water quality guidelines (WQGs) or their equivalent (e.g. environmental quality standards, criteria, objectives or limits). However, a great many more still do not have such frameworks and are looking to introduce practical methods to manage chemical exposures in aquatic ecosystems. There is a potential opportunity for learning and sharing of data and information between experts from different jurisdictions in order to deliver efficient and effective methods to manage potential aquatic risks, including the considerable reduction in the need for aquatic toxicity testing and the rapid identification of common challenges. This paper reports the outputs of an international workshop with representatives from 14 countries held in Hong Kong in December 2011. The aim of the workshop and this paper was to identify ‘good practice’ in the development of WQGs to deliver to a range of environmental management goals. However, it is important to broaden this consideration to cover often overlooked facets of implementable WQGs, such as demonstrable field validation (i.e. does the WQG protect what it is supposed to?), fit for purpose of monitoring frameworks (often an on-going cost) and finally how are these monitoring data used to support management decisions in a manner that is transparent and understandable to stakeholders. It is clear that regulators and the regulated community have numerous pressures and constraints on their resources. Therefore, the final section of this paper addresses potential areas of collaboration and harmonisation. Such approaches could deliver a consistent foundation from which to assess potential chemical aquatic risks, including, for example, the adoption of bioavailability-based approaches for metals, whilst reducing administrative and technical burdens in jurisdictions.     

Development and implementation of surface water quality standards for protection of human health in Korea

Current water quality standards for the protection of human health in Korea include 17 substances found in rivers and streams. Due to increasing concern over the release of hazardous chemicals into the aquatic environment, there has been a demand for additional water quality standards. Therefore, the Korean Ministry of the Environment plans to gradually increase the number of water quality standards to 30 substances, including 22 substances for protection of human health and 8 substances for protection of aquatic ecosystems by 2015. In this study, new water quality standards for protection of human health were established for 1,4-dioxane, formaldehyde, and hexachlorobenzene. We selected candidate hazardous chemicals, conducted a human health risk assessment to determine priority chemicals, established water quality standards based on technical analyses and comparison with domestic and developed countries’ water quality standards, and conducted an expert review. Water quality standards for protection of aquatic ecosystems will be derived in the near future. This study describes how the water quality standards for protection of human health were developed and implemented. Current status, recent expansion, and future plans for water quality standards in Korea are also covered.     

区域地震应急能力优先建设矩阵构建方法的初步研究——以四川省为例

借鉴新一代的时间管理理论——"时间管理优先矩阵",提出并分析了区域地震应急能力优先建设矩阵的概念。分别以区域绝对和相对地震应急能力作为优先建设矩阵中"紧迫与否"和"重要与否"的定量化评价指标,构建了区域地震应急能力优先建设矩阵,划分了能力建设的四种类型,即需重点建设且紧迫性较强的区域类型(第Ⅰ类)、需重点建设但紧迫性较弱的区域类型(第Ⅱ类)、次重要建设但具一定紧迫性的区域类型(第Ⅲ类)和次重要建设且紧迫性较弱的区域类型(第Ⅳ类),在区域能力建设过程中应当遵循从第Ⅰ类到第Ⅳ类建设力度由重到轻、时间由急到缓,逐步开展的原则。最后,以四川省为例,以县(市)为基本评价单元,给出了四川省未来地震应急能力建设的优先等级类型。     

Efficient bio-deodorization of aniline vapor in a biotrickling filter: metabolic mineralization and bacterial community analysis

A biotrickling filter inoculated with commercial mixed microorganisms B350 was employed to treat N-containing odorous vapor - aniline. Results indicated no aniline could be detected when empty bed residence time (EBRT) was larger than 110s at inlet concentration of 0.30 g m(-3). The variation of inlet concentration did not change removal efficiencies when concentration is less than 0.21 g m(-3) at fixed EBRT 110s. Biodegradation mechanism of aniline was tentatively proposed based on identified intermediates and predicted biodegradation pathway as well as final mineralized products. Aniline was firstly biodegraded to catechol, and then to levulinic acid and subsequently to succinic acid. Finally, about 62% aniline carbon was completely mineralized to CO(2), while about 91% aniline nitrogen was converted into ammonia and nitrate. Bacterial community in biotrickling filter was found that at least seven bands microbes were identified for high efficiencies of bioreactor at stable state. In all, biotrickling filter seeded with B350 would be a better choice for the purification odorous gas containing high concentration aniline.