Analysis on Changes of Water Quality in Xuanmen bay due to Construction of Eastern Artificial Lake

Abstract

Abstract In this paper, the data of water quality before construction of Xuanmen eastern artificial lake is compared with the data after construction to analyze the change of water quality inside and outside the lake in Xuanmen bay. After the lake was built, the phosphorus remained basically unchanged, and the salinity dropped sharply in the lake, COD increased sharply, and inorganic nitrogen increased more. The lake is close to a freshwater system. According to local requirement for water, inorganic nitrogen has become a pollution factor. the water quality of the seawater outside the lake was stable, and the construction of the lake had no effect basically on the water quality. Basing on regulation of the basin incoming water quality and lake area, a box model is used to predict the water quality change in the future, it will take 5 years to reach 0.5 below of the salinity. To reduce concentration of nitrogen in the lake, the incoming water needs to be treated to reduce the nitrogen, and at the same time, it should be to take biological measures to reduce nitrogen in order to meet local water quality requirements.