Biomass production and nutrient removal efficiency of Suaeda salsa in eutrophic saline water using a floating mat treatment system

Abstract To explore an economic and practical phytoremediation strategy adapted to remediate hypereutrophic water with high salt content, biomass production and nutrient removal efficiency of Suaeda salsa are determined in eutrophic saline water using a floating mat treatment system. The results suggest that S. salsa, as a pioneer species in coastal tidal flats, has a good ability to tolerate the combined stress of salt and eutrophication under hydroponic conditions, although different levels of salinity have different influence on biomass accumulation. Under optimum-growth saline conditions (274 mM NaCl), the removal efficiency of total nitrogen (TN) and total phosphorus (TP) by S. salsa for hypereutrophic water reaches 73.23% and 72.21%, respectively. The removal efficiency under different levels of eutrophication in the water shows that TN and TP contents in eutrophic saline water are conducive to plant biomass accumulation; the removal efficiency decreases with increasing element concentration. An ecological floating island system suitable for planting S. salsa has been performed and a practical application of S. salsa to remediate eutrophic water resulting from large-scale mariculture carried out. The plant grew well and aquaculture water quality was significantly improved. Therefore, S. salsa could be applied to remediate hypereutrophic water with high salt content.