不同生态工程及其组合系统除藻效率的比较研究

比较了不同水力负荷条件下,由水平流碎石床湿地、下行流湿地、上行流湿地、好氧塘和兼性塘等不同生态工程单元组合而成的5组8套小型处理系统对藻类的去除效率及其变化趋势,并根据适宜水力负荷下各系统除藻效率的季节变化研究了各种组合形式对藻类的去除效果.结果表明:当水力负荷为0.8m³/(m²·d)时,各处理单元对藻类生物量的去除效率均达到最高;好氧塘+下行流湿地系统和水平流碎石床系统均表现出较强的抗水力冲击负荷能力;各生态工程组合系统的除藻效率在夏季最高,对藻类的去除率均超过94%;冬季最低,藻类去除率变动范围为34%～90%.不同类型生态工程的组合方式决定了系统的除藻效率,下行流-上行流湿地的组合对藻类去除效果优于其它组合,季节变化对其运行效果影响不大;水平流碎石床湿地系统对藻类去除效果略逊于其它组合且受季节影响较大.

Comparison of Algal Removal Efficiencies in Different Ecological Treatment Systems and Their Combinations

The algal removal efficiencies and their trends of 8 experimental ecological treatment systems,which belonged to 5 groups,were studied under different hydraulic loading rates(HLR).The algal removal efficiencies were compared according to the seasonal changes under the optimum HLR.Gravel-bed horizontal-flow wetland,down-flow wetland,up-flow wetland,aerobic ponds or facultative ponds combined these systems.The results show that the best HLR is 0.8m³/(m²·d) in all the experimental systems.The systems including aerobic pond and down-flow wetland show a stronger resistance to hydraulic shock loading,as well as horizontal-flow wetland.The algal removal rates of all the systems peaked to over 94% in summer and bottomed in winter that varied from 34% to 90%.It was the combined form that determined the removal efficiency of the ecological treatment systems.The combination system of down-flow and up-flow wetland present the highest capacity of algal removal efficiency and lower seasonal fluctuation,while the gravel-bed horizontal-flow wetland system present the lowest efficiency and higher seasonal fluctuation.