摘要
氯仿是土壤的营养物释放实验中常用的微生物活性抑制剂。文章探讨了在滇池沉积物-自配水系统中投加氯仿后系统中上覆水的氮质量浓度变化(上覆水初始质量浓度:总氮15.0mg·L-1,氨氮7.5mg·L-1,硝氮7.5mg·L-1)以及沉积物中的硝化和反硝化活性的变化。结果表明,实验过程中上覆水的总氮、氨氮和有机氮的质量浓度升高,硝氮的质量浓度降低,加氯仿组和未加氯仿组的总氮分别升高35.9%和46.9%。这是因为实验过程中硝化速率降低而反硝化速率升高导致的。加抑制剂组的上覆水中的总氮和氨氮质量浓度总体上高,硝氮和有机氮总体上低,说明氯仿对硝化反应的抑制作用持续到第816h,在最初和后期抑制作用更显著。加氯仿组的pH值明显高于未加氯仿组,DO质量浓度稍高于未加氯仿组。实验结束后,加氯仿组的沉积物的硝化速率和反硝化速率略低于未加氯仿组的。氯仿在沉积物-水系统中起到一定的抑制作用,使沉积物的硝化速率和反硝化速率均降低,但是硝化反硝化活性并未彻底地被抑制;而且抑制具有一定的时效性。
CH3Cl is usually used as microbe activity inhibiter in soil system for nitrogen concentration variation study. Effect of CH3Cl addition on nitrogen content of overlying water and on nitrification and denitrifieation activity of sediment in sediment-water system were made. The initial total nitrogen, ammonia and nitrate concentration in overlying water are 15.0 mg·L^-1, 7.5 mg·L^-1 and 7.5 mg·L^-1. During the experiment, total nitrogen content, ammonia content and organic nitrogen content of overlying water increased, nitrate content of overlying water decreased, Total nitrogen concentration in overlying water increased 35.9% and 46.9% in CH3Cl addition set and control set, respectively. These were caused by the decrease of nitrification rate and increase of denitrifieation rate. The study indicated that CH3Cl addition set usually had high total nitrogen content and ammonia content but low nitrate content and organic nitrogen content. This stated that nitrification function was inhibited by CH3Cl during all the experiment period, and it was stronger in the initial phase and anaphase than in the other phases. CH3Cl addition set had significantly high pH value and slight high DO content than the control set. At the end of this experiment, both nitrification rate and denitrifieation rate of sediment in CH3Cl addition set were larger than the control set. CH3Cl addition had definite inhibit function in sediment-water system, which caused the decrease of nitrification rate and denitrifieation rate of sediment, but the nitrification reaction and denitrification reaction were inhibited incompletely, and the inhibit function did not persist forever.
出处
《生态环境》
CSCD
北大核心
2006年第6期1133-1137,共5页
Ecology and Environmnet
基金
国家高技术研究发展计划项目(2005AA6010100500)
国家重点基础研究发展规划项目(2002CB412300)
关键词
沉积物
上覆水
氮
氯仿
硝化
反硝化
sediment
overlying water
nitrogen
CH3Cl
nitrification
denitrification
