基于GIS的太湖流域主要生态风险源危险度综合评价研究

以太湖流域主要生态风险源为评价对象，充分考虑多类型多等级风险源作用强度的差异性，构建了风险源危险度评价模型，并在此基础上依据风险源发生机率、强度及作用范围等建立了太湖流域洪涝、干旱、极端气象、土壤侵蚀及污染排放等主要生态风险源的危险度评价指标体系。在ArcGIS技术支持下，创建了太湖流域1 606个网格和24个县市的风险源危险度统计数据库，采用AHP权重法确定指标权重，运用叠加分析、空间分析等技术方法最终实现太湖流域单要素及综合生态风险源危险度的定量评价。结果表明流域内生态风险源的分布存在明显的空间分异规律。其中，高生态风险源危险区集中分布在环太湖北部一带，面积约占流域面积的1172%；较高危险区主要呈“西北 北 东北 东”半环状分布格局，所占面积约2452%，危险度较低的区域集中在流域西南部的苕溪流域一带，面积占1566%。此外，不同区域主导生态风险源组成亦不同，约599%的区域是以污染排放为主导生态风险源，主要分布在镇江 宜兴 长兴 安吉一线以东的地区；2545%的区域主导生态风险源为干旱，主要集中在镇江 宜兴 长兴 安吉一线以西；1244%的区域是以洪涝灾害为主导风险源，集中分布在湖州、宜兴等地；而以水土流失、极端气象灾害作为主导风险源地区相对较为分散，所占比例较小     

春季香溪河库湾CODMn时空分布及其影响因子初探

于2012年春季在香溪河库湾合理布置断面观测，分析水体高锰酸盐指数(CODMn)的时空分布特征，并对CODMn与水体中叶绿素a、溶解氧(DO)、水体垂向稳定系数、总氮(TN)和溶解性硅酸盐(D Si)进行相关分析，以期为香溪河流域有机污染的治理提供支持和指导。结果表明：春季香溪河库湾CODMn浓度变化范围为1.40～5.36 mg/L，4月CODMn均值明显高于3月和5月，为366 mg/L，整个春季CODMn浓度从下游至上游呈现明显增大的趋势。相关分析发现，春季水华暴发期间，CODMn与叶绿素a显著正相关(分别为072和074)，而在未暴发水华的3月二者的相关性不显著。浮游植物和水体稳定系数是影响CODMn变化的主要因素。倒灌异重流使得高含氮、低CODMn浓度的长江干流水体进入库湾下游并稀释CODMn浓度。CODMn与DO在3月和5月的弱相关关系为香溪河CODMn特殊的分布特征提供了其它合理的解释,其分布特征受多种因素的共同影响。春季库湾上游有机污染趋于恶化，限制支流特别是上游污染物的排放是改善有机污染现状的有效途径     

利用重组大肠杆菌SOS法评价污水厂出水的遗传毒性以及工艺去除效果

SOS/umu测试法被广泛应用于化合物和复杂混合物遗传毒性的评价,由于该技术所用菌种为致病菌且操作步骤繁琐等原因,制约了技术的推广应用。研究建立了基于重组大肠杆菌SOS效应的水质遗传毒性检测方法(专利号:ZL201110022476.1),应用该方法评价了某市4座污水厂出水的直接遗传毒性效应,同时以污水处理一厂为例考察了直接遗传毒性效应的季节变化规律以及不同的工艺对水中直接遗传毒性物质的去除情况。结果显示:各污水厂出水均表现出一定的直接遗传毒性,对应的4-NQO毒性当量浓度范围为0.018~0.514 mg·L-1;一年四季中夏季进出水直接遗传毒性效应最高,现有工艺中生化处理工艺段对直接遗传毒性去除效果最佳,去除率为33.33%。该方法操作便利、检测敏感性较高、操作危险性较低,可用于水中直接遗传毒性效应的测试。     

Biodegradation of methyl red by Bacillus sp. strain UN2: decolorization capacity,metabolites characterization,and enzyme analysis

Azo dyes are recalcitrant and refractory pollutants that constitute a significant menace to the environment. The present study is focused on exploring the capability of Bacillus sp. strain UN2 for application in methyl red (MR) degradation. Effects of physicochemical parameters (pH of medium, temperature, initial concentration of dye, and composition of the medium) were studied in detail. The suitable pH and temperature range for MR degradation by strain UN2 were respectively 7.0–9.0 and 30–40 °C, and the optimal pH value and temperature were respectively 8.0 and 35 °C. Mg²⁺ and Mn²⁺ (1 mM) were found to significantly accelerate the MR removal rate, while the enhancement by either Fe³⁺ or Fe²⁺ was slight. Under the optimal degradation conditions, strain UN2 exhibited greater than 98 % degradation of the toxic azo dye MR (100 ppm) within 30 min. Analysis of samples from decolorized culture flasks confirmed biodegradation of MR into two prime metabolites: N,N′dimethyl-p-phenyle-nediamine and 2-aminobenzoic acid. A study of the enzymes responsible for the biodegradation of MR, in the control and cells obtained during (10 min) and after (30 min) degradation, showed a significant increase in the activities of azoreductase, laccase, and NADH-DCIP reductase. Furthermore, a phytotoxicity analysis demonstrated that the germination inhibition was almost eliminated for both the plants Triticum aestivum and Sorghum bicolor by MR metabolites at 100 mg/L concentration, yet the germination inhibition of parent dye was significant. Consequently, the high efficiency of MR degradation enables this strain to be a potential candidate for bioremediation of wastewater containing MR.     

Influence of filtration velocity on DON variation in BAF for micropolluted surface water treatment

Biological aerated filters (BAFs) are widely used for the treatment of micropolluted surface water. However, the biological process produces dissolved organic nitrogen (DON), which, as precursors of nitrogenous disinfection by-products, pose potential threats to drinking water safety. Therefore, to control DON in BAF effluent, it is necessary to study the influence of BAF operation parameters on DON production. In this study, the influence of filtration velocity in a BAF on DON production was investigated. Under different filtration velocity (0.5, 2, and 4 m/h) conditions, profiles of DON concentrations along the media layer were measured. The profile at a filtration velocity of 0.5 m/h showed a decreasing trend, and the ones under filtration velocities of 2 and 4 m/h fluctuated in a small range (from 0.1 to 0.4 mg/L). Moreover, the relatively high filtration velocities of 2 and 4 m/h resulted in a lower level of DON concentration. Additionally, 3D excitation-emission matrix fluorescence spectroscopy was used to characterize DON. It is found that the patterns of DON at a relatively high filtration velocity condition (4 m/h) were obviously different from the ones under low filtration velocity conditions (0.5 and 2 m/h).     

Improve Compliance with Limited Resources by a Three-Group Inspection Regime

Frequent monitoring and relatively high fines are usually necessary to bring about improvements in environmental quality, but more challenging for many countries with limited human, material, and financial resources is to put them into practice. This paper developed a three-group model of a state-dependent enforcement in a repeated game to improve the policy implementation under limited inspection capacities. A certain number of firms are grouped (group 1, group 2, group 3) for different supervision intensity (e.g., the order of inspection probability corresponding to each group is p ₁?<?p ₂?<?p ₃) based on their environmental performance. The optimal policy parameters, such as inspection probability of each group and the probability that a firm found in compliance is moved to a better reputation group, were obtained as the basis for regulator’s policy making. Numerical simulations indicated that the three-group inspection regime can significantly increase compliance rate as compared with static enforcement with the same monitoring probability. Among the number of firms in each group under steady state conditions, group 2 had the most, group 1 was the second, and group 3 had the smallest. Analysis and prediction of a three-group reputation example provided a good experiment for the model. The results give a practical reference for the policy makers with inspection capacity constraints to achieve higher compliance rate.     

基于污染物排放许可的总量控制制度改革研究

污染物总量控制制度改革是基于排污许可制的环境管理制度体系改革的重点内容之一。文章分析了总量控制制度与排污许可证制度的关联关系,现有的排污行可证制度对总量控制制度融合的要求,从许可排放量确定、分配、实际排放量核算与核定等角度,深刻剖析了总量控制制度与排污许可证制度融合存在的技术和机制两大障碍。最后就污染物总量确定、许可排放量分配、实际排放量核算与责任机制等三方面为构建基于排污许可证的总量控制制度提出了改革思路和建议。     

基于机器视觉的鱼类行为特征提取与分析

近年来,水污染问题备受关注。生物式水质监测成为目前国家环境保护工作的重要任务之一。为准确监测水质污染情况,本文以青鳉鱼(Oryzias latipes)为研究对象,采用非接触式的机器视觉监测技术,提取青鳉鱼的生理特征(呼吸频率)和运动特征(胸鳍和尾鳍的摆动频率),并分析这些特征与水质之间的关系。本文采用支持向量机(Support Vector Machine,SVM)准确提取鱼鳃,并根据鱼鳃呼吸面积大小变化计算出鱼的呼吸频率。基于形态学细化算法提取青鳉鱼骨架,求出胸鳍和尾鳍的摆动频率。结果显示:不同浓度铜离子暴露实验测得的青鳉鱼生理特征和运动特征与实际情况一致;通过对不同铜离子浓度下的毒性实验数据对比,发现了青鳉鱼的生理特征和运动特征会随不同的铜离子浓度发生相应变化,可以作为水质监测的评价标准。     

基于排污许可的环境标准制度改革完善研究

排污许可制度是固定点源环境管理的基础核心制度,政府以排污许可证为载体,对固定污染源的污染物排放限值、排污行为等进行许可,以排放标准的要求作为基本依据,并以环境质量标准为依据,对非达标区实施更为严格的排污许可限制。然而,现有的部分行业排放标准由于制定时间较早、科学技术支撑方法不足、与环境质量改善难以挂钩等问题,难以满足新排污许可证制度改革要求。本文在研究现行环境标准体系对排污许可制度的支撑作用与相互关系的基础上,研究了基于排污许可制的排放标准存在的主要问题,并以健全排污许可制度的环境标准支撑为目的,提出了现行环境标准体系的完善和修订建议。     

Effects of pig manure containing copper and zinc on microbial community assessed via phospholipids in soils

Pig manure (PM) is widely used as an organic fertilizer to increase yields of crops. Excessive application of compost containing relatively great concentrations of copper (Cu) and zinc (Zn) can change soil quality. To clarify the effects of different rates of application and to determine the optimal rate of fertilization, PM containing 1,115 mg Cu kg^?1, dry mass (dm) and 1,497 mg Zn kg^?1, dm was applied to alkaline soil at rates of 0, 11, 22, 44, 88, and 222 g PM kg^?1, dm. Phospholipid fatty acids (PLFAs) were used to assess soil microbial community composition. Application of PM resulted in greater concentrations of total nitrogen (TN), NH₄ ⁺-N, NO₃ ^?-N, total carbon (TC), soil organic matter (SOM) but lesser pH values. Soils with application rates of 88–222 g PM kg^?1, dm had concentrations of total and EDTA-extractable Cu and Zn significantly greater than those in soil without PM, and concentrations of T-Cu and T-Zn in these amended soils exceeded maximum limits set by standards in china. Except in the soil with a rate of 11 g PM kg^?1, dm, total bacterial and fungal PLFAs were directly proportional to rate of application of PM. Biomasses of bacteria and fungi were significantly greater in soils with application rates of 44–222 g PM kg^?1, dm than in the soil without PM. SOM, TC and EDTA-Zn had the most direct influence on soil microbial communities. To improve fertility of soils and maintain quality of soil, rate of application should be 22–44 g PM kg^?1 dm, soil containing Cu and Zn.