Analysis on the Trend of Sewage Interception and Pollution Control and Water Quality Status of Shuimo River(Gumudi River and Laolong River) in Urumqi from 2018 to 2021

Urumqi City has carried out the pollution control work of Shuimo River(Gumudi River and Laolong River) since 2018. The water quality monitoring results showed that the upstream Miquanqiao and Sanzhuang sections have eliminated the inferior level V in the third quarter of 2020, especially in 2021, after the tail water of the upstream sewage plant was separated through the backwater pipeline. The water quality of the river was basically stable at Class IV and above. In the middle and lower reaches of Shuimo River(Gumudi River and Laolong River), there are domestic and sewage plant tail water entering, so that the water quality of each section in the middle and lower reaches was basically maintained at the inferior level V. The water quality pollution index has been rising along the way following the order of Miquanqiao < Sanzhuang < Wollongong South Gate < Huangjialiang Reservoir interception gate, but the comprehensive water pollution index of each section basically showed a downward trend year by year and quarter by quarter. According to the proportion distribution of water quality index pollution load in each section, the nutrient salt and organic pollution index with the highest proportion and the physicochemical and inorganic anion index fluoride and the whole section were analyzed by the method of "average concentration of index/average comprehensive pollution index change of water body".The change trend of water pollution degree of similar water quality in two periods within the same pollution level was analyzed. Compared with the base year of 2018, the pollution degree of each section of Shuimo River(Gumudi River and Laolong River) was significantly reduced in 2021. The pollution levels of nutrient salts and organic pollution indicators of the section were significantly reduced, and the fluoride pollution levels of physical and chemical indicators and inorganic anions were significantly reduced. It can be seen that after a series of rectification measures such as increasing environmental protection economic investment, implementing the river(lake) long system,strengthening the management of river waters, carrying out the upgrading and renovation of sewage treatment plants,and constructing drainage pipeline projects, the pollution control has been comprehensively promoted. The Shuimo River(Gumudi River, Laolong River) has achieved remarkable results in pollution control.