Water hyacinth (Eichhornia crassipes) waste as an adsorbent for phosphorus removal from swine wastewater

Both live plants and dried straw of water hyacinth were applied to a sequential treatment of swine wastewater for nitrogen and phosphorus reduction. In the facultative tank, the straw behaved as a kind of adsorbent toward phosphorus. Its phosphorus removal rate varied considerably with contact time between the straw and the influent. In the laboratory, the straw displayed a rapid total phosphorus reduction on a KH2PO4 solution. The adsorption efficiency was about 36% upon saturation. At the same time, the water hyacinth straw in the facultative tank enhanced NH3-N removal efficiency as well. However, no adsorption was evident. This study demonstrated an economically feasible means to apply water hyacinth phosphorus straw for the swine wastewater treatment. The sequential system employed significantly reduced the land use, as compared to the wastewater stabilization pond treatment, for pollution amelioration of swine waste.