新型人工湿地对工业区降雨径流的净化研究

Treatment Studies of Industrial Rainoff With a New Type of Constructed Wetland

根据东莞市同沙水库集水区内工业区降雨径流的水质、水量特征,采用新型折流式人工湿地对其进行模拟及实地降雨径流净化研究.对人工湿地不同运行阶段模拟降雨径流的净化效果进行对比,分析COD、SS、TN、TP、NH4+-N以及重金属Pb、Zn、Cu在湿地系统中的沿程变化,探讨它们的主要去除机制.模拟净化研究中,除TN外,湿地系统出水各污染物均达到《地表水环境质量标准》(GB 3838-2002)Ⅲ类质量标准,TN达Ⅳ类标准;且大部分污染物在湿地前端被去除.实地降雨径流净化研究中,COD、SS、TN、TP及NH4+-N的平均去除率分别为90.9%、97.0%、83.4%、92.2%、90.0%;重金属Pb、Zn、Cu的平均去除率分别为98.4%、94.1%、93.6%,出水均能达地表Ⅲ类水标准.研究表明,折流式人工湿地系统对工业区降雨径流的净化效果显著,湿地系统具有较强抗冲击负荷能力.另外,小幅温度变化对湿地系统中污染物的去除影响不大.

According to water characteristics of industrial rain runoff in a catchment of Tongsha reservoir,Dongguan city,an improved baffled constructed wetland（BCW） was used for purification experiment study of simulated and on-the-spot rain runoff.The purification effects of simulated rain runoff were compared in different operated phases of BCW.Meanwhile,the variation of the pollutants（COD,SS,TN,TP,NH＋4-N,Pb,Zn,Cu） along the BCW and their removal mechanism were analyzed and discussed,respectively.In the simulated experiment,the effluent water quality of BCW system met the needs of Environmental Quality Standard for Surface Water（GB 3838-2002） Ⅲ,besides TN met Ⅳ,and most of the pollutants were removed in the front of the BCW.In the purification study of on-the-spot rain runoff,removal rate of COD,SS,TN,TP and NH＋4-N were 90.9%,97.0%,83.4%,92.2% and 90.0%,respectively;removal rate of Pb,Zn and Cu were 98.4%,94.1% and 93.6%,respectively.The effluent met the grade Ⅲ.Results showed that there was remarkable treatment performance of industrial catchment rain runoff when BCW system was used,which also can withstand strong shock load.Moreover,a modest variation of temperature affected the removal of pollutants in the BCW insignificantly.