人工湿地不同工艺的污染物去除及微生物群落结构分析

Pollutant Removal of Constructed Wetland with Different Wastewater Treatment Processes and Analysis of the Changes in Microbial Community Structure in It

实验监测湿地系统中ρ(TN),ρ(NH4+-N),ρ(TP),ρ(CODCr)和ρ(BOD5)的沿程变化情况,并应用PCR-DGGE技术对湿地5种运行工艺的微生物群落结构进行了研究,结果表明:不同工艺组合的污染物浓度均沿程下降,但去除效率存在一定的差异性.DGGE指纹图谱分析结果表明,不同工艺组合细菌多样性指数(H)、丰度(S)和均匀度(EH)均有所不同.其中两级潜流细菌多样性指数沿程有所增加,其余工艺细菌多样性指数沿程都略有下降;单一的潜流或表流运行工艺的微生物丰度要远小于组合工艺的微生物丰度.对不同工艺组合细菌群落相似性分析结果表明,两级潜流沿程细菌群落相似度下降,潜流+表流组合工艺沿程细菌群落相似度上升,两级表流沿程细菌群落相似度呈现出先升高后下降的趋势.

In this study,the changes in TN,NH＋4-N,TP,CODCr,and BOD5 mass concentrations of different wastewater treatment processes were measured,and the microbial communities of five operating processes were investigated by PCR-DGGE.The results showed that the contaminants decreased along the direction of water flow in different wastewater treatment processes,though their removal efficiencies were different.The DGGE profiles showed that Shannon-wiener index（H）,richness index（S） and evenness index（EH） of different operating processes were different.The Shannon-wiener index of the two-stage subsurface constructed wetland system increased along the flow and decreased slightly along the flow in the other operating processes.The microbial richness index of the combined process was much greater than that of any individual operation.The results of microbial community similarity analysis indicated that in the two-stage subsurface flow wetland the similarities decreased along the flow,while an opposite trend was observed in the process of two-stage surface flow wetland.In the combined process,however,the similarities rose first and then declined.These differences were associated with the operation processes of constructed wetland.