Comparison of Algal Removal Efficiencies in Different Ecological Treatment Systems and Their Combinations
不同生态工程及其组合系统除藻效率的比较研究

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.