The protective effect of green space on heat-related respiratory hospitalization among children under 5 years of age in Hanoi,Vietnam

Environmental Science and Pollution Research - Combined effects of global warming and rapid urbanization replace green spaces with urban facilities. Children in urban areas are at a higher risk of...     

生产性IC反应器厌氧颗粒污泥的生物学特征

IC反应器以絮状污泥接种用于处理酒糟废水,运行至第180d时分别测定反应器第1、第2反应室颗粒污泥的VSS、产甲烷活性、胞外多聚物和辅酶F420等各项生物学指标。结果表明反应器内颗粒污泥具有较强活性,反应器COD去除率基本稳定在95%以上,出水COD不超过1000mg/L。     

沸石颗粒在污泥絮体中的形态及其对污泥泥水分离的影响

投加沸石粉提高了活性污泥的泥水分离性能。通过对沸石颗粒表面生物膜和投加了沸石粉的活性污泥絮体生长过程及成熟形态的微观观察,结果表明沸石颗粒不仅可以作为微生物载体长成生物膜,而且成为菌胶团核心和污泥絮体骨架,改善了污泥絮体的颗粒结构,从而增强了絮体强度,提高了絮体密度,降低了污泥塑性。研究结果表明沸石粉适宜的投加量为4g/L;在活性污泥中投加4g/L沸石粉后,SVI从193降低到155,污泥比阻从27.36×1012m/kg降低到5.67×1012m/kg;在沸石粉含量小于10g/L时,随着沸石粉含量的增加,污泥呈现压缩沉淀时界面沉速和出现压缩沉淀的时间持续减小。     

沉积物中多环芳烃和有机氯农药定量分析的质量保证和质量控制

以美国ＥＰＡ为方法为基础,进行了沉积物中多环芳烃和有机氯农药分析的质量保证和质量控制实验,采用回收率指示物控制回收率,用内标法定量。结果表明多环芳烃的指示物回收率为５０．６７－９７．３３％,目标化合物的回收率为５８．６７－９６．３３％,方法检测限为３．３０－９．２６μｇ．ｋｇ＾－１。     

铁屑对低浓度含铬地下水的处理研究

以某铬渣污染场地上抽提上来的低浓度含铬地下水作为实验研究对象。选用铁屑对含铬废水进行处理。通过静态试验考察了影响六价铬去除率的因素:pH、铁屑用量、反应时间,得到了较好的反应工艺参数。并在静态试验的基础上,用铁屑填充自制的反应柱研究了动态试验的效果。结果表明:六价铬的出水浓度低于0.05 mg/L,达到GB/T 14848-93《地下水质量标准》Ⅲ类排放标准。     

Potential energy production from organic waste and its environmental and economic impacts at a tertiary institution in Palestine

Municipal solid waste (MSW) is one of the most well-known biomass resources that can be utilized to produce renewable energy. Numerous countries are plagued by the proliferation of waste, particularly organic waste that can be utilized for energy recovery. Palestine suffers from inefficient solid waste management, and only recently have a few projects focused on bioenergy production been implemented. Throughout the years, the city of Tulkarm experiences power outages which cause a challenge to the Palestine Technical University-Kadoorie campus in Tulkarm. Thus, the possibility of energy recovery from the organic portion in Palestine Technical University-Kadoorie was evaluated. The analysis of an economic impact included discussions of a number of economic aspects, including Levelized cost of energy, internal rate of return, present worth, annual worth, and payback period. On the other hand, a carbon dioxide savings analysis and gas emission were evaluated. The outcomes of the energy optimization demonstrated that the suggested system could supply the institution with an average of roughly 7 MWh of electrical energy. According to the economic study, this project offers 0.25 million dollars in present value, 0.144 million dollars in annual value, a 13 percent internal rate of return, a payback period of 6 years, and a levelized cost of energy of 0.11 dollars for each kWh generated. Additionally, the environmental assessment revealed that this system might reduce CO₂ emissions by around 8,343,778 tons. For effective waste management, energy recovery, and emission reduction, it is advised to implement anaerobic digestion technology.     

扶梯乘员坠落的法律归责思考与对策

扶梯乘员坠落事故已经发生多起,如何进行相关风险的辨析并提出防范对策,是电梯从业者难以回避的课题.本文试从生产者、经营管理者之角度就此课题进行“归责”与“对策”的辨析与思考,希冀关注者有所借鉴,防范已经存在或可能发生的风险.     

Predicting organic contaminant concentrations in sediment porewater using solid-phase microextraction

Because of its cost and time saving features, solid-phase microextraction (SPME) is a leading candidate as a biomimic technique in assessing the bioavailable fraction of hydrophobic organic contaminants (HOCs) in sediment porewater. However, no predictive modeling framework in which to systematically address the effect of key parameters on SPME performance for this application exists. In this study, we derived two governing equations to predict (1) the minimum sediment volume (V(s)min) required to achieve non-depletive conditions, and (2) dissolved phase HOC porewater concentrations (C(pw)) as functions of HOC- and sediment specific characteristics in a conceptual three compartment system. The resulting model predicted that V(s)min was independent of HOC concentrations both in sediment and porewater, but did vary with hydrophobicity (characterized by logK(ow)), the fraction of sediment porewater (f(pw)), and the volume (V(f)) of the SPME sorbent phase. Moreover, the effects of these parameters were minimized (i.e., V(s)min reached plateaus) as logK(ow) approached 4-5. Model predictions of C(pw), a surrogate for SPME-based detection limits in porewater, decreased with increasing sediment volume (V(s)) at low V(s) values, but rapidly leveled off as V(s) increased. A third result suggested that the sediment HOC concentration required for SPME is completely independent of K(ow). These results suggest that relatively small sediment volumes participate in exchange equilibria among sediment, porewater and the SPME fiber, and that large sediment HOC reservoirs are not needed to improve the detection sensitivity of SPME-based porewater samplers. The ultimate utility of this modeling framework will be to assist future experimental designs and help predict in situ bioavailability of sediment-associated HOCs.     

生物表面活性剂及其在环境修复中的研究进展

生物表面活性剂是由微生物分泌的天然产物,由于其物理性质和化学结构与许多人工合成的表面活性剂相似,并且对土壤、淡水、海洋等生态系统毒性较低,因而在环境污染治理方面,特别是在重金属和石油等有机溶剂污染的原位和异位生物修复方面具有极大的应用潜力.主要综述了近年国内外生物表面活性剂在廉价制备、作用机理、环境修复中的研究进展.     

西安地区旅游景点水体卫生细菌学调查及保护对策

以粪大肠菌和异养细菌总数做指标，对西安地区旅游景点水体的卫生细菌学状况进行了调查。结果表明，西安市区内旅游景点的人工湖、天然湖等大都受到不同程度的污染，而离市区较远、海拔较高的旅游景点则污染较轻。