潜流人工湿地对污染物去除率的正交实验研究

以湿地污染物去除率为考察指标,通过正交实验分析了植物、流量和水位对去除率的影响。结果表明：3种因素对BOD5、CODMn和TN去除率的影响一致,均为植物〉流量〉水位;植物是BOD5、CODMn和TN去除率的显著性影响因素,其中大薸对3种污染物的去除率显著高于凤眼莲,但其在9月底易发生二次污染,需要及早收割,流量是TN和CODMn去除率的显著性因素,水位为不显著因素;BOD5、CODMn和TN浓度在系统的前端下降速率较大,随后逐渐减小并趋于平稳,表明大部分污染物在湿地的前端被去除,湿地整体截污能力尚有较大提升空间。应用中可选择大薸在北方推广,并充分利用湿地后端潜能,最大化处理污染源水体。

Orthogonal experiment on removal rate of pollutant in subsurface flow constructed wetland

The effect of plant,flow and water level on pollutant removal of constructed wetland was investi-gated through orthogonal experiments. Results show that there are almost similar effects of three indicatorson removal rate of BOD5,CODMn and TN,and plant has better effects than others,flow is in the secondposition, and water level is the last one. Pistiastratiotes generally have more effective removal rate thanEichhorniacrassipes,but at the end of September,it may cause secondary pollution,so it is important toharvest in time. Flow is significantly related to removal rate of TN and CODMn,but it is not for water lev-el. The concentration of BOD5、CODMn and TN experienced sharp drop in the front of the constructed wet-land bed,and the downward trend slow down gradually and finally went stable. Those processes indicatethat almost all the pollutant was removed in the front of wetland bed,and the intercepting pollution capaci-ty of whole wetland system can be improved significantly. Pistiastratiotes are recommended to be planted innorth China area,and take full advantage of carrying capacity of wetland systems to deal with water pollut-ed sources.