6GERSBERG R M, ELKINS B V, LYON S R, et al. Role of aquatic plants in wastewater treatment by artificial wetlands[J]. Wat Res, 1986, 20(3): 363- 368.
7MOSS B. Engineering and biological approaches to the restoration for eutrophication of shallow lakes in which aquatic plant communities are important components [ J ].Hydrobiologia, 1990, 200/201: 367 - 377.
8TANNER C C, CLAYTON J S, UPSDELL M P. Effects of loading rate and planting on treatment of dairy farm wastewaters in constructed wetlands Ⅱ . Removal of nitrogen and phosphorus [J]. Wat Res, 1995, 29(1):27 - 34.
9HARBERL R, PERFLER R, MAYER H. Constructed wetlands in Europe [J].Wat. Sci. Tech., 1995, 32(3):305-315.
10VERMAAT J E, HANIF M K. Performance of common duck- weed species (Lemnaceae) and the waterfem Azolla filiculoldes on different types of waste water [ J]. Wat Res,1998,32(9) :2569 - 2576.