巢湖水质分析评价与治理对策
Water Quality Analysis Evaluation and Countermeasures in Chaohu Lake

巢湖位于安徽省中部，是安徽境内最大的湖泊。为探究近年来巢湖水质变化，对2015年至2020年巢湖湖区14~23个水质监测点的高锰酸盐指数、氨氮、总磷、化学需氧量、五日生化需氧量和营养化指数及状态6项重要水质指标，共1800余组水质监测数据进行了分析。监测结果表明，巢湖东半湖水质优于西半湖水质，通过对各项指标进行年均数值变化趋势分析和季节性Kendall趋势分析，2015年至2020年总体呈现高度显著下降趋势，尤其是巢湖西半湖氨氮、化学需氧量和五日生化需氧量项目从IV~V类，变好至III类，说明近年来巢湖水质得到较为明显的改善。结合巢湖水质现状，对水环境影响因素进行分析，巢湖水环境主要受到外源污染如入湖河流、工业废水、生活污水等和内源污染的影响。巢湖的水环境治理应以源头控制为主，内部治理为辅，制定更具针对性的治理措施。
Chaohu Lake is located in the central part of Anhui Province and is the largest lake within the province. In order to explore the changes of water quality of Chaohu Lake in recent years, six important water quality indicators including permanganate index, ammonia nitrogen, total phosphorus, chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD) and eutrophication index of 14~23 water samples from 2015 to 2020 were selected, with a total of more than 1800 groups data. The results showed that the water quality of the eastern part of Chaohu Lake is better than that of the western part. Through the analysis of annual average value change trend and seasonal Kendall trend of various indicators from 2015 to 2020, there was a highly significant downward trend overall, especially the ammonia nitrogen, chemical oxygen demand, and five-day biochemical oxygen demand items in the western part of Lake getting better from Class IV~V to Class III, indicating that the water quality has been significantly improved in recent years. Based on the current water quality status, an analysis is conducted on the factors affecting the water environment. The water environment is mainly affected by external pollution such as incoming rivers, industrial wastewater, domestic sewage, and internal pollution. The water environment governance of Chaohu Lake should focus on source control, supplemented by internal governance, and formulate more targeted measures.