Study On Water Quality Evaluation And Pollution Prevention Measures For Small And Micro Water Bodies In Guangzhou

After successfully implementing the river head system to control river and lake pollution in China,many provinces and cities,including Guangdong,have begun to focus on the treatment of small and micro water bodies.However,at present,there is less attention to small and micro water bodies,and there is less research on water quality status and system investigation,which has affected the pollution control and water quality improvement of small and micro water bodies.The paper takes 10 small and micro water bodies in Guangzhou as the research object,conducts sampling analysis and research respectively in the normal and high water periods,analyzes the pollution sources according to the data,and uses a variety of statistical methods to evaluate the water quality,finds out the degree of water pollution of small and micro water bodies,and puts forward targeted treatment plans based on a comprehensive understanding of the pollution situation of small and micro water bodies.The main research progress and achievements are as follows:(1)Identify the water quality indicator characteristics of 10 typical small and micro water bodies during the normal and high water periods.From the analysis of monitoring indicators,it can be seen that the water quality indicators of small and micro water bodies exceed the standard seriously,with the most common factor exceeding the standard being total nitrogen.The water quality indicators of small and micro water bodies exhibit obvious spatial characteristics.Whether in the northern or central regions,the water quality indicators of small and micro water bodies in industrial and densely populated areas are generally exceeding standards,resulting in serious pollution.(2)Perform source analysis on small and micro water bodies.Based on the characteristics of water quality indicators and on-site investigation results,it was found that the three major pollution sources of small and micro water bodies in Guangzhou are:(1)non-point source pollution caused by rainfall runoff;(2)Pollution caused by various types of sewage discharge and leakage;(3)Pollution caused by residents randomly dumping garbage and washing sewage.(3)Using statistical methods to conduct water quality evaluation and quantify the degree of pollution and eutrophication in small and micro water bodies.The results of the mean comprehensive pollution index method and principal component analysis method indicate that the water quality of nine small and micro water bodies does not meet the Class V standard specified in the "Surface Water Environmental Quality Standard"(GB3838-2002),and total nitrogen is the main pollution factor for small and micro water bodies.The range of exceeding standards for total nitrogen in small and micro water bodies is 1.06～12.4,and the range of pollution sharing rate is 18.4%～58%.The eutrophication degree of small and micro water bodies was evaluated using methods such as the comprehensive nutritional status index and projection pursuit model.The results showed that among the 10 small and micro water bodies studied,the comprehensive nutritional status index(TLI)ranged from 36.73 to 80.24,and 9 small and micro water bodies were in an eutrophication state.Among them,4small and micro water bodies were mild eutrophication,2 small and micro water bodies were moderate eutrophication,and 3 small and micro water bodies were severe eutrophication.(4)In response to the widespread problem of eutrophication,combined with the conditions and pollution sources of small and micro water bodies,this article proposes a targeted strategy for improving the water quality of small and micro water bodies based on the principle of "one micro,one policy".