湖泊水体中硫酸盐增高的环境效应研究

通过对高原３个硫酸盐浓度差异的湖泊沉积物水界面硫的形态分布、扩散通量和碎屑有机硫通量等估算，揭示了湖泊水体硫酸盐增加以后的环境效应和自然反馈机制．研究认为：水体向沉积物内部扩散和界面硫酸盐还原作用是高硫酸盐浓度水体硫酸盐的主要清除作用，随硫酸盐浓度的增加，它在水体清除硫酸盐作用的贡献逐渐增大，而低硫酸盐含量湖泊水体生物同化吸收作用是水体硫酸盐的主要清除机制，它在硫酸盐浓度不同的水体没有差异．     

Occurrence and congeners specific of poiychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls (PCBs) in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% ofΣPCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% ofΣPCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs.     

锑的淡水水质基准及其对我国水质标准的启示

针对我国锑水生生物水质基准缺乏的问题，收集筛选了锑对淡水水生生物的急性和慢性毒性数据，使用评价因子法、毒性百分数排序法和物种敏感度分布法分别推导我国锑的淡水水质基准，通过综合分析和比较，选择物种敏感度分布法推导的急性和慢性的水质基准值（466.62μg/L和88.71μg/L）作为最终的基准推荐值.通过与国内外现有锑相关水质标准进行比较，提出在我国相关水质标准修订中分别制定保护水生生物和人体健康水质标准的建议，避免水质标准对水生生物的"过保护"问题.     

区域环境质量综合评价的一种方法——Fuzzy概率法

本文应用Fuzzy概率原理,在对区域环境内各单项污染指标进行分级评价的基础上,考虑各单项污染指标在总体中的权重,并综合各单项污染指标的作用,给出区域环境内环境“总”质量的综合评价。     

金属对催化还原DDT的降解产物及其反应机制的研究

本报告介绍DDT经金属对处理后降解产物的分析鉴定和有关反应机制的初步研究。 降解产物主要是用气相色谱—质谱联用分析鉴定的。水溶液中的DDT用Cu-Zn金属对还原其降解产物经鉴定是DDD、DDMS、DDE_t,它们是DDT分子脱去烷基碳原子上不同数目的氯原子的产物。而在Cu-Fe金属对作用下,水溶液中的DDT的还原则是同时得到四种不同类型的产物。它们是DDT脱去烷基碳原子上的1个和3个氯原子的DDD和DDE_t;DDT脱氯、氧化产物DBP和DBH;DDT脱去HCI生成的DDE;两个DDT分子二聚脱氯的产物TTTB和TTDB。 实验证明金属对对DDT的作用是催化还原反应,金属对起着催化剂和还原剂双重作用。通过实验结果对DDT在金属对作用下的反应机制进行了初步探讨。     

Promotive effect of pyridine on indole degradation by activated sludge under anoxic conditions

Batch experiments were carried out to investigate the promotive effect of pyridine on indole degradation under denitrifying conditions. The seed sludge was obtained from a local coal-coking wastewater treatment facility and was acclimated in the laboratory. Indole and pyridine were supplemented to the synthetic wastewater at different ratios. The optimum ratio of chemical oxygen demand (COD) to nitrate (C/N) was 8.4–8.9 for both denitrification and indole and pyridine degradation. At a temperature of 28°C and pH of 7.0–7.5, the nitrate reductase activity (NRA) was in the best state. The addition of pyridine could promote NRA and the degradation of indole. When the initial concentration of indole was 150 mg/L, the concentration ratio of indole to pyridine was in the range of 1–10. Under optimum C/N conditions, the degradation of indole could be described with pseudo-zero-order kinetics. There was no accumulation of nitrite during the reaction. When the concentration ratio of pyridine to indole was less than 0.25 with an increase in the pyridine proportion, there were more significant augment rates for NRA and the degradation of indole than the situation when the concentration ratio was more than 0.25. __________ Translated from Environmental Science, 2006, 27(2): 300–304 [译自: 环境科学]     

水霉科真菌在北京地区不同污染水体中的分布和数量变化

对北京地区水霉科真菌在不同污染水体中分布和数量变化的调查研究表明,水霉科游动孢子在水体中的数量随水体污染程度的变化而不同:一般在净水中较少,在轻度污染至中度污染的水体中明显增多,污染加重时逐渐下降,在重污染区明显减少,在近于毒污染的水体中则几乎绝迹.可见水霉科真菌在不同污染水体中的分布和数量变化具有一定的规律性,将其用作对水体进行综合评价的一项生物指标的可行性值得进一步研究.     

金属铁还原降解2,4-二硝基甲苯的实验研究

研究了金属铁对2,4-二硝基甲苯(2,4-DNT)的还原降解情况.实验结果表明,2,4-DNT的还原降解与溶液初始pH值、初始浓度和溶解氧等因素有关.氯离子能消除金属铁的钝化现象.金属铁表面附载的铜对2,4-DNT的还原降解具有催化作用.     

均质滤料过滤截污模型研究

对均质滤料过滤进行了分析，采用毛细管模型研究过滤水流，给出毛细管中剪切应力的分布，通过毛细管中颗粒物的受力分析，求得颗粒与毛细管壁间的物理化学作用力。对颗粒在毛细管在毛细管中运动的受力平衡进行分析简化，得到了截污饮和时滤床中孔隙率的计算公式，由此可以计算出均质滤床的最大截污能力，即：清洁滤床的孔隙率与孢和孔隙率之差乘以滤床的体积。     

膨润土吸附－絮凝法处理污水中的重金属离子

研究了天然膨润土对Ｐｂ￣（２＋）、Ｃｄ￣（２＋）、Ｃｒ￣（３＋）的吸附和膨润土的絮凝沉降条件，将吸附与絮凝过程结合起来形成处理污水的新工艺，加入０．０４％膨润土和０．００６％的ＰＡＣ可使低浓度污水中Ｐｂ￣（２＋）脱除９３．１％。