无机离子对芘与天然溶解性有机质结合系数的影响

从天津市北塘河口沉积物提取了天然溶解性有机质(dissolved organic matter,DOM),利用荧光淬灭法测定了芘与所得DOM的结合系数KDOM,并研究了不同离子强度及离子类型对KDOM的影响.结果表明,DOM对芘的KDOM为1.27×105L·kg-1,远高于固态有机质的吸附能力,说明DOM对多环芳烃等憎水性有机污染物在水环境中的归趋具有不可忽视的影响.随着阳离子浓度的增加,芘的KDOM呈现先降低,再升高,然后稳定在某一值的复杂变化趋势.不同阳离子对芘的KDOM具有不同的影响,而所研究阴离子对KDOM影响不大。     

Biodegradation of pyrene by Phanerochaete chrysosporium and enzyme activities in soils: Effect of SOM, sterilization and aging

The impacts of soil organic matter （SOM）, aging and sterilization on the production of lignin peroxidase （LIP） and manganese peroxidase （MnP） by Phanerochaete chrysosporium during the biodegradation of pyrene in soils were investigated. The biodegradation of pyrene by P. chrysosporium decreased with increasing SOM content, whereas the maximum activities of LiP and MnP increased, which indicates that SOM outweighed pyrene in controlling enzyme production. Sterilization enhanced the degradation of pyrene due to the elimination of competition from indigenous microbes, whereas aging led to a reduction in the degradation of pyrene primarily through changes in its sorbed forms. Both sterilization and aging could reduce SOM content and alter its structure, which also influenced the bioavailability of pyrene and the enzyme activity. The sterilization and aging processes caused changes in the degradation of pyrene, and the enzyme activities were greater in soils with high SOM contents. MnP was related to the degradation of pyrene to a greater extent, whereas LiP was more related to the decomposition of SOM.     

偶氮染料对斜生栅藻的毒性作用及结构活性相关性研究

为了揭示不同结构染料对水生生态系统的毒性作用,研究９种偶氮类及２种蒽醌类染料对斜生栅藻的生长抑菌作用,并通过剖析毒性一结构之间的相关关系,探讨了偶氮染料的毒作用机理,１１种染产对斜生栅藻的４８ｈＥＣ５０在１．０９－４１．２２ｍｇ．Ｌ＾－１之间,偶氮染料分子中所包含偶氮键的个数及芳香环上取代基的亲水性和电性均影响染料的毒性,进一步证实偶氮染料的毒同理为Ｎ－Ｎ键不宾为一ＮＨ２后,形成Ｎ＋离子活性民生物     

主次波长分光光度法测定水中氨氮

在碱性介质中,氨与Nessler试剂反应生成黄色化合物.用依据悬浮颗粒对光吸收原理建立显色反应的主次双波长光度测定氨氮(NH_3-N)新方法.方法检出限0.02mg/L,精密度RSD<2％,加标回收率93％-105％,且计算曲线稳定,适合于天然水、废水等环境水质监测.     

Perfluoroalkyl acids in dust on residential indoor/outdoor window glass in Chinese cities: occurrence,composition, and toddler exposure

Environmental Science and Pollution Research - The dust on indoor and outdoor surfaces of the window glasses were collected using sterile cotton balls in 11 cities from China. Two sampling...