Properties of mercuric reductase from a HgCl_2-resistant fungus

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模拟酸雨下土壤中稀土元素的环境化学行为和植物可利用性研究

研究了模拟酸雨对两种土壤中稀土元素的环境化学行为和植物可利用性的影响．结果表明，酸雨的酸度及淋洗量皆对稀土元素的淋溶产生影响，酸雨淋洗使土壤中稀土元素的形态含量发生了改变．由回归分析得知，有效态稀土的主要存在形态是交换态和松结有机态，实验表明，稀土的植物可利用性随模拟酸雨淋洗液的酸度增大而减小．     

日光/H_2O_2/草酸铁体系对垃圾渗滤液深度处理的试验研究

以草酸铁络合物/H2O2作光氧化剂,利用日光对垃圾渗滤生化出水进行了光氧化降解试验。结果表明,在溶液的初始体系pH=3.0,H2O2投加量为460mg/L,Fe3+质量浓度为20mg/L条件下,反应60min后,CODCr去除率可达80%以上;溶液初始体系的pH、H2O2和Fe3+的投加量及废水的水质对光解过程有显著影响,而且在太阳光照射下,CODCr去除率比紫外光照射下高。研究表明,在一定试验条件下,用日光/H2O2/草酸铁体系对城市垃圾渗滤液处理效果较好,可作为垃圾渗滤液的深度处理。     

水体pH和曝气方式对藻类生长的影响

利用水族箱微宇宙研究了藻类在不同pH和曝气条件下的生长和种类变化.使用天然湖水,一组试验每天调节pH,使其分别保持在8.0、8.5、9.0和9.5;另一组试验是设定不同的曝气方式,分别为不曝气、完全曝气、昼间曝气和夜间曝气,定期测定水体叶绿素a和藻类组成.pH试验结果显示,在pH 8.0～9.5范围内,pH 8.5下藻类生长状况最好,pH 9.5下生长最差,人为改变pH使其远离8.5能够抑制藻类生长.曝气试验结果显示,曝气不能抑制水体中藻类的生长,昼间曝气甚至还有明显的促进作用.     

Reaction-enhanced mass transfer and transport from non-aqueous phase liquid source zones

The objective of the following research is to theoretically quantify the enhancement of interphase mass transfer of dissolved non-aqueous phase liquid (NAPL) compounds from the non-aqueous phase to the aqueous phase and the enhancement of dispersive mass transport from a NAPL zone due to destruction of dissolved NAPL compounds. For relatively slow reaction rates, such as for permanganate and perchloroethene (PCE), local-scale mass transfer enhancement is expected to be small. Dispersive mass transport with reaction from a horizontal NAPL zone can be quantified using equations derived for a mathematically equivalent falling film reactor system. In contrast to local-scale interphase mass transfer, dispersive mass transport from NAPL zones may be significantly increased by reaction. Enhancement factors due to destruction of the NAPL compound(s) are mainly dependent on NAPL solubility and oxidant concentration and to a lesser extent on reaction rate, stoichiometry, and transverse dispersion coefficients. Higher NAPL solubility and/or lower oxidant concentration reduces the maximum expected enhancement factor. Reaction enhancement factors for mass transport from NAPL zones are expected to be in the range of 5-50 for permanganate and chlorinated solvents. Theoretical results suggest that assuming instantaneous reaction rates may be appropriate for dispersive mass transport from NAPL zones.     

Bioaccumulation of the rare earth elements lanthanum, gadolinium and yttrium in carp (Cyprinus carpio)

Widespread use of the rare earth elements (REEs) in China for agricultural purposes, together with many other applications, has resulted in a remarkable increase of REE concentrations in the environment. The comparative bioaccumulations of representative light, medium and heavy REEs in a variety of tissues of carp (Cyprinus carpio L.) were investigated for an evaluation of their impacts on aquatic animals. The fish were exposed continuously to solutions containing 0.50 mg litre(-1) of each element for 45 days at pH 6.0 and sacrificed at time intervals. Skeleton, muscle, gills and internal organs were analysed for REE contents. A method using cation-exchange resin separation and ICP-AES determination was developed for the quatification of individual REEs. The results show that carp has low ability to take up the REEs under the experimental conditions. The order of REEs under the experimental conditions. The order of maximum bioconcentration factors was mostly internal organs > gills > skeleton > muscle. Neither synergistic nor antagonistic effects of the mixed REE solutions for carp were observed. The relative distributions of different REEs in the investigated tissues exhibited similar patterns. Among the selected tissues studied, the concentration of a heavy REE (Y) was the smallest, while concentrations of a medium (Gd) and a light REE (La) showed only a slight difference.     

污染水中还原性指标相关性探讨

本文介绍了模拟污染水中还原性指标ARs,MRS,BPM,COD,BOD的相关性,以及它们与衡量水变黑程度色阈值之间的关系。     

水中杀菌剂叶青双及其降解物的反相液相色谱测定

本文用反相液相色谱法测定水中叶青双及其降解物2-氨基5-巯基-1,3,4-噻二唑。平均回收率分别为91％和94％;对水样的最低检测浓度分别为2ppb和0.8ppb;叶青双与2-氨基-5-巯基-1,3,4-噻二唑的分离度为2.5。本法在柱效和灵敏度上比硅胶柱液相色谱法有明显的提高。     

水源水生物预处理反应器微生物学特征

处理微污染水源水的生物陶粒反应器中，细菌的数量分布具有一定的区域化特征，上层生物陶粒的细菌数量较中、下层生物陶粒的细菌数量分别高１～２个数量级。从生物陶粒反应器中分离出７２株细菌，其中最多的是假单胞菌属，占４４．６％，其次为克雷伯氏菌属细菌，占２ｌ．６％。另外还分离到芽孢杆菌属、不动细菌属、黄单胞菌属和邻单胞菌金的细菌。除芽孢杆菌属外，其它各属细菌生反应器中的分布特征是上层多，下层少。     

污水土地处理试验工程慢速渗滤系统对优先有机污染物的净化

本文通过模拟实验及现场考察,研究了天津污水土地处理试验工程中慢速渗滤系统对优先有机污染物的净化效率以及该系统经处理污水后对土壤及作物的影响进行了探讨.