Water Purification of High-Salinity River by Floating Bed Grown Aquatic Plants

Nowadays, water pollution and eutrophication problem of rivers and lakes are widely and serious in China. Floating bed grown aquatic plants was applied to remove nutrient pollutants from the high-salinity river water. The experimental results showed that reed, Lythrum salicaria Linn and Alternanthera philoxeroides were the suitable species in this project. SD value in the river test section was significantly improved by floating beds, while TN, NH₄⁺-N, TP concentration declined by a certain degree. Removal of TN and NH₄⁺-N improved significantly, for their concentration decreased by 38.9% and 33.2%, respectively. Microorganism quantity in the reed rhizosphere was detected periodically, such as heterotrophic bacteria, nitrite bacteria, denitrifying bacteria, and so on. Meanwhile, correlation of the microbe and nutrient removal efficiency was studied. There was significant positive correlation between the number of nitrite bacteria and NH₄⁺-N removal rate. The pilot test results provide some useful information for ecosystem restoration of high-salinity river.