Study on Phosphorus Removal Using Water Hyacinth to Treat Sewage in Shanghai Rural Area

The research of phosphorus removal mechanism in water hyacinth pond, which was used to treat sewage in Shanghai rural area, was carried out. There were three possible ways, plant absorption, assimilation by microorganism attached to the roots of water hyacinth and combination of sedimentation and suspended microorganisms, that phosphorus could be removed from the system. It was found that water hyacinth absorption was the main mechanism of phosphorus removal in water hyacinth ponds, which accounted for 83%, and the other 13% was achieved by sediment and microorganisms´ metabolism. In order to help the design of water hyacinth pond used to treat sewage in rural area where the lack of professional and technical personnel is the obstacle, the paper made evaluation tables for phosphorus removal capabilities of water hyacinth pond on three certain water depth (0.4m, 0.8m and 1.2m), which can be used in assessing pollutant removal capacities of water hyacinth pond. Due to the high performance of phosphorus absorption of water hyacinth, the water hyacinth pond had good performance on phosphorus removal at 62% of pollutant loads that were listed in tables.