5Kivaisi A K.The potential for comtructed wetlands for wastewater treatment and reuse in developing countries:a review[J].Ecol Eng,2001,17(16):545-560.
6Nguyen L M.Organic matter composition.microbial biomass and microbial activity in gravel-bed constructed wetlands treating farm dairy wastewaters[J].Ecol Eng,2000,16(2):199-221.
7Drizo A,Frost C A,Grace J,et al.Physico-chemical screening of phosphate-removing substrate for use in constructed wetland systems[J].Water Res,1999,33(17):3595-3602.