表面流人工湿地污染物去除与运行参数的相关性及其反应动力学

为了探讨利用人工湿地处理农村污水的效益状况，以表面流人工湿地为研究对象，探析人工湿地去除污染物的运行规律。自2017年8月至2019年5月，每周采集水样一次，共累计取样88组；分别测定SS，BOD₅，TN，TP等污染物指标以及流量（Q）、水温（T），DO，pH值等运行指标；并分析了SS，BOD₅，TN，TP等4种污染物的出水浓度、去除率、表面污染物负荷（PLR）分别与表面水力负荷（HLR）、水力停留时间（HRT）的相关性，以及4种污染物的一级反应速率常数（k_V）与Q，HLR，HRT的相关性，最后根据线性相关性方程计算出4种污染物k_V的温度修正表达式k_T。研究结果发现：在采样数据范围内BOD₅，TN，TP的出水浓度与HLR成正比，与HRT成反比；SS的出水浓度与HLR成反比，与HRT成正比；BOD₅，TN，TP的去除率与HLR成反比，与HRT成正比；SS的去除率与HLR成正比，与HRT成反比；SS，BOD₅，TN，TP的PLR与HLR成正比，与HRT成反比。SS，BOD₅与TP的k_V与Q，HLR正相关趋势较显著；TN的k_V与HLR趋势正相关不显著，水温变化对SS的k_V影响很小，水温变化对BOD₅，TN，TP的k_V有一定的影响。掌握表面流人工湿地污染物去除与运行参数的相关性及其反应动力学，可为研究湿地系统去除污染物机理以及在不同环境温度下工程设计参数的选择提供了理论基础。

Correlation between pollutant removal and operation parameters of surface flow constructed wetland and its reaction kinetics

In order to investigate the benefits of treating rural sewage in constructed wetland,the surface flow constructed wetland was taken as the research object to explore the operation rules of removing pollutants.From August 2017 to May 2019,88 groups of water samples were collected once a week.Pollutant indexes such as SS,BOD5,TN and TP,as well as operational indexes such as flow (Q),water temperature (T),DO and pH value were measured respectively.The correlation between effluent concentration,pollutants removal efficiency,pollutants loading rate (PLR) of SS,BOD5,TN,TP and hydraulic loading rate(HLR),hydraulic retention time (HRT) was analyzed,as well as the correlation of the first-order reaction rate constants (kV) of the four pollutants with Q,HLR and HRT.Finally,according to the linear correlation equation,the temperature modified expression kT of the four pollutants kV was calculated.The results show that the effluent concentrations of BOD5,TN and TP are proportional to HLR and inversely proportional to HRT within the sampling data range.The effluent concentration of SS is inversely proportional to HLR and directly proportional to HRT.The removal rates of BOD5,TN and TP are inversely proportional to HLR and directly proportional to HRT.The removal rate of SS is directly proportional to HLR and inversely proportional to HRT.The PLR of SS,BOD5,TN and TP are proportional to HLR and inversely proportional to HRT.The positive correlation between kV,Q and HLR of TP and SS,BOD5 is significant.kV of TN is not significantly positively correlated with HLR trend,and the change of water temperature has little effect on kV of SS,while the change of water temperature has certain effect on kV of BOD5,TN and TP.Mastering the correlation between pollutant removal and operation parameters of surface flow constructed wetlands and its reaction kinetics provides a theoretical basis for the study of pollutant removal mechanism in wetland system and the selection of engineering design parameters at different environmental temperatures.HQ]