长春市土壤微生物生化作用与重金属化学形态关系研究

研究了长春市土壤微生物的生化作用强度（氨化作用强度、固氮作用强度,纤维素分解强度和土壤基础呼吸）与重金属（Pb、Cd、Cu、Zn和Ni）化学形态的关系。通过科学采样和实验室测试分析了不同功能区土壤中,重金属含量和化学形态与微生物生化作用强度,并使用相关分析、偏相关分析多种数据统计方法进行数据处理。结果表明：各功能区因土地利用方式的差别和土壤中重金属的各种化学形态对土壤微生物生化作用强度有不同的影响。其中氨化作用与交换态Cd、Zn和Ni含量呈显著正相关;固氮作用与土壤重金属各化学形态相关性均不显著;呼吸作用与铁锰氧化物结合态Pd和交换态Cu呈显著正相关;纤维素分解作用强度与交换态Pd含量呈显著负相关。在土壤理化性质等相关变量受控时,重金属化学形态对微生物生化作用强度的影响有较明显的变化。其中与无控制变量相比,在控制变量作用下,纤维素分解作用强度受交换态Pd影响上升了0.0314,表现为交换态Pd抑制纤维素分解作用强度。呼吸作用与交换态Pd的相关系数在无控制因素情况下为-0.1425,在有控制因素情况下为-0.3230,表明交换态Pd促进呼吸作用强度。而有机结合态Ni表现为抑制固氮作用。因此可利用交换态Pd与纤维素分解作用强度、呼吸作用强度的相互关系,有机结合态Ni与固氮作用的相互关系等相结合来评价城市土壤重金属污染状况。文章为评价长春城市土壤重金属污染提供了微生物学指标的理论依据。     

Effect of humic substances on the anaerobic digestion of secondary sludge in wastewater treatment plants: a review

Environmental Chemistry Letters - Anaerobic digestion is a promising technology for energy recovery from secondary sludge, yet the presence of humic substances in wastewater limits anaerobic...     

Plan integration for resilience scorecard: evaluating networks of plans in six US coastal cities

Planning for hazard mitigation is frequently detached from other planning activities that influence development patterns in hazardous areas. Consistent integration of mitigation reduces hazard vulnerability for people and the built environment. We apply a plan integration for resilience scorecard in six US coastal cities to evaluate the integration of local networks of plans and the degree to which they target areas most vulnerable to flooding hazards. We find that plan integration scores vary widely across the six cities, and that some plans actually increase vulnerability in hazard zones. Policies also frequently support mitigation in areas with low vulnerability, rather than in areas with high vulnerability. The plan integration for resilience scorecard can generate information to improve hazard planning by allowing planners to identify conflicts between plans, assess whether plans target areas that are most vulnerable, and better inform decision makers about opportunities to mainstream mitigation into multiple sectors of planning.     

一体化设备处理某乡镇微污染地下水工艺研究

针对乡镇地下水微污染的特点,研究石英砂一沸石过滤器、膜组件与紫外线消毒器一体化设备处理效果,当进水浊度在15—36NTU,出水浊度达0．2—0．5NTU,去除效率达98％-99．3％;进水氨氮浓度范围为0．4～1．4mg／L,反应3．5min后出水的氨氮浓度小于0．5mg／L;微生物指标去除率为100％。采用一体化设备处理乡镇微污染地下水可行。     

Inactivation, reactivation and regrowth of indigenous bacteria in reclaimed water after chlorine disinfection of a municipal wastewater treatment plant

Disinfection of reclaimed water prior to reuse is important to prevent the transmission of pathogens. Chlorine is a widely utilized disinfectant and as such is a leading contender for disinfection of reclaimed water. To understand the risks of chlorination resulting from the potential selection of pathogenic bacteria, the inactivation, reactivation and regrowth rates of indigenous bacteria were investigated in reclaimed water after chlorine disinfection. Inactivation of total coliforms, Enterococcus and Salmonella showed linear correlations, with constants of 0.1384, 0.1624 and 0.057 L/(mg·min) and R² of 0.7617, 0.8316 and 0.845, respectively. However, inactivation of total viable cells by measurement of metabolic activity typically showed a linear correlation at lower chlorine dose (0-22 (mg·min)/L), and a trailing region with chlorine dose increasing from 22 to 69 (mg·min)/L. Reactivation and regrowth of bacteria were most likely to occur after exposure to lower chlorine doses, and extents of reactivation decreased gradually with increasing chlorine dose. In contrast to total coliforms and Enterococcus, Salmonella had a high level of regrowth and reactivation, and still had 2% regrowth even after chlorination of 69 (mg·min)/L and 24 hr storage. The bacterial compositions were also significantly altered by chlorination and storage of reclaimed water, and the ratio of Salmonella was significantly increased from 0.001% to 0.045% after chlorination of 69 (mg·min)/L and 24 hr storage. These trends indicated that chlorination contributes to the selection of chlorine-resistant pathogenic bacteria, and regrowth of pathogenic bacteria after chlorination in reclaimed water with a long retention time could threaten public health security during wastewater reuse.     

Hydrodynamics and water quality of the Hongze Lake in response to human activities

Environmental Science and Pollution Research - The hydrodynamics and water quality of a lake in response to human activities is an important yet poorly understood issue. In this study, the...     

Sulfobacillus benefaciens强化中度嗜热菌群浸出铅锌硫化矿尾矿过程机制

针对铅锌硫化矿尾矿生物浸出周期长和效率低的问题,本研究采用Leptospirillum ferriphilum（L. ferriphilum）和Acidithiobacillus caldus（A. caldus）等比例混合构建了中度嗜热菌群,浸出铅锌硫化矿尾矿.引入一株兼性自养铁/硫氧化微生物Sulfobacillus benefaciens（S. benefaciens）,考察其对中度嗜热菌群浸出尾矿过程的影响.结果表明,中度嗜热菌群（L. ferriphilum+A. caldus）8 d Zn浸出率达到93.94%.随着S. benefaciens引入,浸出环境保持更高的氧化还原电位和微生物活性,浸出过程中Fe³⁺浓度以及总铁浓度增加,4 d内Zn浸出速率提升了13.63%,8 d内Zn浸出率达到96.08%,S. benefaciens的加入强化了中等嗜热菌群的浸出效率.相关性分析表明多糖、蛋白质以及溶解性有机碳（DOC）与浸出过程中的溶液介质参数变化具有统计学意义上显著性和强相关性.表面官能团以及胞外聚合物（EPS）结果证实,引入S. benefaciens在浸出过程中促进菌群产生更多的蛋白质和碳水化合物,有助于提高中度嗜热菌群的浸出效率,加快浸出铅锌硫化矿尾矿中有价金属,降低其环境毒性.     

北京城区屋面径流中PAHs的污染特征与来源解析

以北京典型城区屋面径流中的PAHs为研究对象,在2008年雨季采集了不同地点的屋面径流,分析了溶解相和颗粒相PAHs的质量浓度,对屋面径流中PAHs的质量浓度特征、时空变化规律及来源进行了讨论。结果表明,屋面径流具有较严重的PAHs污染,16种PAHs在溶解相中的总质量浓度为563.85~937.01 ng.L-1,来源主要是机动车排放（31.9%）、煤燃烧（39.6%）、天然气燃烧（15.3%）及石油类的挥发（14.2%）;在颗粒相中的总质量浓度为844.48~1372.62 ng.L-1,来源主要包括燃煤（51.8%）、汽油（38.1%）和柴油（10.1%）的燃烧等。BaP的EMC平均值（172 ng.L-1）远远超过我国污水排放标准（30 ng.L-1）,且以颗粒相为主。不同地点采集的屋面径流中的PAHs质量浓度大部分表现出较明显的初期效应和时间变化,而在不同采样点之间则没有明显的空间差异。