The characteristics of ammonia nitrogen in the Xiang River in Changsha, China

¹ Chinese Research Academy of Environmental Sciences, 100012 Beijing, China
² Changsha Uranium Geology Research Institute, CNNC, 410007 Changsha, China
³ School of River and Ocean Engineering, Chongqing Jiaotong University, 400074 Chongqing, China

^a Corresponding author: huanggx@craes.org.cn

Abstract

Changsha is a highly industrialized city in Hunan Province, China, where the water quality is of great importance to the development of economy and environment in this area. We have analyzed the characteristics of ammonia nitrogen in the Xiang River in Changsha from 2016 to 2019. The results showed that in the main stem, concentrations of ammonia nitrogen were very low and reached the third water quality level. In the six tributaries, concentrations of ammonia nitrogen have increased, especially in Longwanggang and Liuyang River, where the latter of which has a large number of industries and domestic sewage. Correlations between monthly precipitation and ammonia nitrogen concentrations were negative, besides two sites Jinjiang and Juzizhou, indicating that in most rivers, ammonia nitrogen contents had been diluted by rainfall. In general, concentrations and fluxes of ammonia nitrogen have decreased significantly during this time period, suggesting that water environment has improved greatly under the series of the clean motions by the local government.