复合垂直流人工湿地对氮的净化效果

Effect of Integrated Vertical-flow Constructed Wetland on Nitrogen Removal

采用复合垂直流人工湿地处理武汉东湖污染水的中试结果表明 ,出水中NH+ 4-N、NO- 2 -N和凯氏氮 (KN)浓度均显著降低 ,而NO- 3-N含量有所上升 ;系统最佳运行水力负荷为 80 0mm/d ,超过此负荷后系统净化效果随负荷增加而下降 ;在东湖现有的污染负荷下 ,处理系统仍呈现出继续承载污染量的潜力 ;就基质中KN的分布而言 ,水平方向为下行流池含量高于上行流池 ,垂直方向为上层 >中层 >下层 ,而在植物体内的分布则为叶片中含量最高。

A pilot test was conducted with integrated vertical-flow constructed wetland to treat polluted water from East Lake in Wuhan.Result shows that the concentrations of NH^+_4-N,NO^-_2-N,Kjeldahi nitrogen (KN) in the effluent is reduced remarkably while NO^-_3-N is increased slightly.The system optimal hydraulic load is 800 mm/d.When this optimal value is overloaded,the purification effectiveness decreases with the increase of hydraulic load.Under the present pollution load in East Lake,the system still has the potential of bearing pollution.From the KN plane distributing in substrates,the nitrogen content of down-flow chamber is higher than that of up-flow chamber.From the KN vertical distribution,the nitrogen content of top layer is higher than that of medium layer,bottom layer has the minimum content.The highest concentration is in leafage based on the KN distributing in the plants.