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-How wetland, down-flow wetland, Up-flow wetland, aerobic ponds or facultative ponds combined these systems. The results show that the best HLR is 0.8m(3)/(m(2).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.
Wu Zhen-bin; Wu Xiao-hui; Fu Gui-ping; Cheng Shui-ping; He Feng; Deng Ping.Comparison of algal removal efficiencies in different ecological treatment systems and their combinations,Huanjing Kexue,2006,27(2):241-245