太湖流域断头河道微循环水质效应与生物响应

针对太湖流域断头河道微循环过程中水质效应和生物响应不清楚的问题，笔者通过水槽模拟实验，分析了氮磷和有机物等水质指标随水体微循环时间、频率的变化关系；通过常州武进洛阳镇徐家头浜实际河道微循环实验，探讨了微循环运行过程中实际河道水质的稳定性，微循环过程中实际河道的生物响应，及浊度、溶解氧、pH等环境因素的影响。结果表明：水槽模拟实验条件下微循环对水体氨氮去除的影响最为明显（去除率达62.91%），COD去除率变化幅度受微循环频率的影响最大（可达50%）；微循环设置后实际河道COD浓度下降趋势明显（降幅约30%）；微循环过程中河道水体浮游动物和浮游植物数量均呈上升趋势，而河道边坡和底泥中Proteobacteria、Bacteroidetes、Actinobacteria、Acidobacteria等优势微生物菌群的丰度却有不同程度的变化。同时，浊度对总磷和COD的影响程度相当，溶解氧和pH对水体氨氮浓度的影响均最显著。该研究为改善断头河道水质提供新方向，为微循环技术的实际应用提供数据参考。

Water Quality Effect and Biological Response of Decapitated River Microcirculation in Taihu Lake Basin

In order to solve the problem of water quality effect and biological response in the microcirculation process of beheaded river in Taihu Lake Basin,the relationship of nitrogen,phosphorus,organic matter and other water quality indexes with the time and frequency of water microcirculation was studied through flume simulation experiment.Through the actual river microcirculation test in Xujiatou Bang,Luoyang Town,Wujin District,Changzhou,this paper finds out the stability of actual river water quality in the process of microcirculation operation,and makes clear the influence of environmental factors such as turbidity,dissolved oxygen and pH value.The biological response of the actual river in the process of microcirculation is also discussed.The results show that under the condition of flume simulation test,microcirculation has the most obvious effect on the removal of ammonia nitrogen in water (the removal rate reaches 62.91%).The change of COD removal rate is most affected by the flow rate of microcirculation with 50%.After the setting of microcirculation,the actual COD concentration in river channel has an obvious decreasing trend (about 30%).The number of zooplankton and phytoplankton increase in the process of microcirculation,but the abundance of dominant microflora such as Proteobacteria,Bacteroidetes,Actinobacteria and Acidobacteria in river slope and sediment change in different degrees.At the same time,turbidity has the same effect on total phosphorus and COD,and dissolved oxygen and pH value have the most significant effect on the concentration of ammonia nitrogen in water.This study provides a new direction for improving the water quality of broken river and provides data support for the practical application of microcirculation technology.