潜流人工湿地处理农村生活污水动力学研究

Kinetics of Rural Sewage Treatment by Constructed Wetland

考察潜流人工湿地处理农村生活污水的运行效果,并探寻一级动力学常数的空间变化情况,采用"厌氧调节池+二级串联潜流式人工湿地"工艺处理农村生活污水。结果表明,经过3个月运行后人工湿地对污水中COD、TP、TN和NH3-N的去除率分别达到了79.13%,71.54%,57.26%和60.01%。通过湿地原位检测显示以上各类污染物在生物床内都有较明显的沿程下降趋势,在床体的前半部分污染物的降解较快,后半部分相对缓慢。农村生活污水中污染物去除动力学符合一级动力学模型,一级生物床中COD、TP、TN和NH3-N的去除,Kv均值分别为3.048、2.469、1.625和1.695;二级生物床中Kv均值分别为2.542、1.946、1.383和1.453。生物床Kv呈现出减小的趋势说明生物床前端对各类污染物的降解速率比后端快。生物床间的跌水池的复氧,增加了二级生物床前端的Kv,提高了对污染物的降解速率。

A kinetics study was conducted on a constructed wetland（CW） system treating rural domestic wastewater,consisting of an anaerobic equalization tank plus two-stage subsurface-flow CW.Based on three-month operation,the paper presented result of pollutant removals of COD,SS,TP,TN and NH3-N by the CW system indicating remarkable a decrease of pollutants in the CW system.The degradation of pollutants followed the pseudo-first order reaction model in general,while degradation rate（Kv） was faster in the 1st stage than in 2nd stage of the CW system;however,measures such as re-aeration by water-drop could increase Kv of 2nd stage wetland.