pH对沟渠沉积物截留农田排水沟渠中氮、磷的影响研究  

Effect of pH on retention of N and P in ditch sediments

作　　者：席北斗[1] 徐红灯[1,2] 翟丽华[3] 王京刚[4] 

机构地区：[1]中国环境科学研究院 [2]北京化工大学环境工程系北京100029 [3]清华大学环境科学与工程系 [4]北京化工大学环境工程系

出　　处：《环境污染与防治》2007年第7期490-494,共5页Environmental Pollution & Control

基　　金：国家"973"计划项目(No.2005CB724203;No.2002CB410800-07;No.2002CB412300)。

摘　　要：通过摇瓶动态实验和箱体静止实验,研究了不同pH条件下沟渠沉积物对农田流失氮、磷的截留效应,分析了pH对氮、磷截留效应及其界面交换作用的影响。结果表明:在实验pH变化范围内,沟渠沉积物对NH4+-N的吸附量和NO2--N的硝化量以及对TN的截留率都是随着pH的增加而增加;沟渠沉积物对总溶解性磷(TDP)的吸附量随着pH的增加而增加,TP的截留率在5d前随pH的增加而增加,但在此后基本不发生变化;在不同的pH下,通过影响微生物的活动直接或间接影响氮的界面交换行为,同时pH通过影响沉积物的吸附作用和离子交换作用来影响磷在沉积物-水界面的交换行为。阐明pH对沟渠沉积物氮、磷截留效应的影响有助于掌握氮、磷在农田排水沟渠中的迁移转化机理,从而对控制农业面源污染具有重要的意义。Series of dynamic and static experiments were performed to study the effects of ditch sediments on the fate of N and P at acidic, basic and neutral pH （5, 7 and 9）, the pH effect on the N and P retention in the sediments, and the mass transfer at the sediment-water interface. The adsorptive capacity of the sediments for NH^＋4-N, nitrification to produce NO^-4-N and retention of TN all increased with increasing pH, which also enhanced the sediments′ ad- sorptive capacity for TDP and increased the retention of TP during the first 5 days. The transfer of N species at the sediment-water interface was affected due to the pH＇s effect on the microbial activities and that the transfer of P species at the interface was affected due to pH＇s effect on absorption and ionic exclusion. Knowing the effects of pH on N and P retention in ditch sediments will help to understand the transfer and transformation of N and P species in agriculture drainage ditch, which is important for effective control of agricultural non-point source pollution.

关 键 词：氮 磷 截留 沟渠沉积物农田排水沟渠pH 

分 类 号：X52[环境科学与工程—环境工程]