STUDY ON MEASURES TO IMPROVE WATER QUALITY IN URBAN LAKES: CASING IN LAKE NANHU IN WUHAN

摘要

Water pollution is an important factor that plagues urban development and affects human settlements. This study takes Lake Nanhu in Wuhan, China as an example to discuss the water quality improvement of typical urban park lakes. Based on the monitoring results of the water quality in the lake and the quantitative analysis of the pollutant sources in the basin, the engineering measures under various scenarios are proposed as well as the corresponding pollutant reduction. The results show that the total nitrogen (TN) environment capacity of the lake is 315.2 t/a and the total phosphorus (TP) environment capacity is 21.01 t/a, which are calculated by Dillon model. Under the circumstance of the tail water from sewage treatment plant transferring from Lake Nanhu to the Yangtze River, 60% of TN from sediment release and domestic sewage interception are controlled, 67.3% from surface runoff pollution are reduced, the TN emission can be controlled below the water environment capacity and its concentration can reach 1.5mg/L. When the tail water from sewage treatment plant transferring from the lake to river, 75% of TP from domestic sewage and sediment release are controlled, and the reduction rate of TP from surface runoff pollution is 87%, the TP emission can be controlled below the water environment capacity and its concentration can reach 0.1 mg/L. After then, the environment and ecology of the lake can be improved. The feasibility plan of water quality improvement in this lake obtained in this paper can provide experience and case reference for the treatment of the same urban park-type lakes.