Effects of a Combined Biological Restoration Technology on Nitrogen and Phosphorus Removal from Eutrophic Water

For this study we applied a biological restoration technology combined with introducing filter-feeding bivalves (Hyriopsis cumingii), stocking planktivorous fish (silver carp), and replanting submerged macrophytes (Ceratophyllum demersum L.) in order to treat eutrophic water. The effects of this combined biological restoration measure on remedying eutrophic water were investigated, and the main mechanisms of this combined measure for nutrient transportation and transformation were revealed. The results showed this combined biological restoration measure effectively reduced nutrient nitrogen (N) and phosphorus (P) loads in the water. The assimilation and absorption of submerged macrophytes and the nutrient transformation from water to the sediments were the main mechanisms for water N and P removal. In conclusion, the combination of different biological restoration measures may be a potential choice for water managers in eutrophic water restoration.