太湖典型入湖河道中氨氮去除研究

入湖河流是湖泊营养物质的一个重要来源,因此入湖河道水质的改善是控制湖泊富营养化的关键。文章采用自行研制的新型仿生填料直接布设在河道内的生物接触氧化法,在不影响河流生态结构和原有使用功能的前提下,对河流微污染水体进行氨氮的去除研究。研究结果显示,氨氮的净去除率在5.35%~39.91%,其中最高为7月的39.91%,最低月为12月的5.35%。试验期间生物膜的平均厚度为0.8~1.1mm(雨后略厚),生物膜内的微生物主要是一些贫营养微生物,数量少,因此形成的生物膜较薄,生物膜由表及里几乎全是好气层。同时,根据氨氮去除率与硝化菌的数量关系也可以看出试验河段内氨氮的去除主要是靠硝化菌的硝化作用来完成的。

Ammonia-nitrogen degradation in the typical streams entering Taihu Lake

The reduction of ammonia-nitrogen fluxes from the polluted stream to lake is an important task in areas with limnetic eutrophication. Biofilm technique for polluted streams has been proposed as one method to reduce mmonia-nitrogen fluxes entering lakes. In this study, the degradation effect of ammonia-nitrogen in created biomembrance purification engineerings was analyzed in a pollued stream (Linzhuanggang) in western Tai Lake.Results showed that the ecological engineering in the stream would reduce the nitrogen transport to TaiLake with approximately 5.35%~39.91%. The average thickness of the biofilm was in 0.8~1.1mm during trial period (slightly thicker after the rain), bacteria attached to biofilm were mainly oligotrophic bacteria, and the formed biofilm was the thinner, so almost all the biofilm was in an aerobic environment. Meanwhile, according to the quantitative relationship between ammonia- nitrogen removal and bacteria, the degradation of ammonia- nitrogen was mainly completed by nitrobacteria.