低C/N对湿地中硝化反硝化作用的影响  

Influence of low C/N on nitrification and denitrification in wetlands

作　　者：廖晓数[1,2] 贺锋[1] 徐栋[1] 陶敏[1,2] 吴振斌[1] 

机构地区：[1]中国科学院水生生物研究所,淡水生态和生物技术国家重点实验室,湖北武汉430072 [2]中国科学院研究生院,北京100049

出　　处：《中国环境科学》2008年第7期603-607,共5页China Environmental Science

基　　金：湖北省科技攻关重大项目(2006AA305A03);国家“十五”科技项目(2002AA601021);国家杰出青年基金资助项目(39925007)

摘　　要：通过监测几种形态氮的变化,研究了人工湿地小试系统在不同浓度和低C/N条件下的除氮效果和反硝化途径.结果发现,湿地对浓度为5.5～50.5mg/L的NH4+-N有很好的去除效果,去除率可达95%以上.在此浓度范围内,NH4+-N的进、出水浓度呈线性关系,R2值为0.9971.当进水含氮量低于16.4mg/L时,湿地的除氮效率随进水浓度的增加而明显增加.进水含氮量为16.4～51.4mg/L时,湿地的除氮效率为85%以上,且浓度对去除率无显著影响.当C/N<1时,湿地系统对总氮的去除率为86.3%,而碳源充足的情况下去除率也仅有85.8%,低C/N对湿地的除氮效果没有显著影响.反硝化可能存在不需要消耗碳源的途径,即在微生物的作用下,NH4+-N浓度为30mg/L左右时便直接将NO2--N还原成N2,此时有机质不是湿地脱氮效果的直接限制因素.Content variation of different nitrogen form were measured to investigate the denitrification approaches in wetlands with different concentration nitrogen and low C/N value in influent. The removal rate of ammonia could reach 95% when the concentration of ammonia varied from 5.5mg/L to 50.5mg/L in the influent. Within this concentration range, there was a linearity relation between the concentration of ammonia in influent and that in effluent presented with the value of RE reaching 0.9971. The removal rate of total nitrogen increased as concentration of nitrogen increasing when the concentrations were below 16.4mg/L in the influent and the total nitrogen removal rate reached 85% when concentration of total nitrogen varied from 16.4mg/L to 51.4mg/L. Removal rate of nitrogen achieved 86.3% when value of C/N was less than l, while it was only 85.8% in wetland with ample carbon. It indicated that there was no significant influence of the content of COD in influent to the removal efficiency of NH4^＋-N. Denitrification approach demanding no carbon was deduced to be that NO2^--N could be deoxidized to N2 by NH4^＋-N at the concentration of 30 mg/L, owing to the function of microorganisms, and it suggested that COD content should not be the directly limited factor of removal efficiency of nitrogen.

关 键 词：湿地 氨氮 有机质 反硝化 

分 类 号：X703.1[环境科学与工程—环境工程]