Purification of Micro-polluted Waters Using Vegetated Floating Bed Made of Carbon Fiber
Lythrum salicaria Linn,Typha minima Funk and Iris pseudacorus,the three species aquatic plants growing in frigid regions,were selected as plants used in vegetated floating bed for cleaning of water-body. In this paper,a bench-scale experiment was conducted with the vegetated floating bed made of a special kind of carbon fiber,and the vegetated floating bed was intended to purify slightly-polluted water. In addition,the experimental water-body was aerated with a compressor.Purification effects of these three plants were studied respectively,and removal of pollutants in terms of COD,NH4+-N and TP by carbon-fiber floating bed was examined. The experiment focused on purification effects of these three plants on micro polluted water,which showed that the most suitable plants for floating bed,among others,was Lythrum salicaria Linn,followed by Typha minima Funk and Iris pseudacorus. It was reported that the floating bed system planted with Lythrum salicaria Linn showed very high removal efficiencies with respect to turbidity,COD,NH4+-N and TP when the hydraulic retention time of the water-body was 2 d and the air/water ratio 2 ∶1;however,removal of TN in the water by the floating bed system was not good.