人民长江2024，Vol.55Issue(5)：49-56,8.DOI:10.16232/j.cnki.1001-4179.2024.05.007
南水北调中线总干渠污染物降解及自净能力研究
Study on water self-purification process in main channel of Middle Route of South-to-North Water Diversion Project
摘要
Abstract
The self-purification process is an important factor influencing changes in the water quality of rivers and lakes,and the degradation coefficient of pollutants is the key parameter determining the self-purification ability of water bodies.The quanti-tative analysis of the self-purification function of the channel in long-distance water transport is of great significance for under-standing the water quality change process and distinguishing the influence of other external factors on the water quality change.U-sing permanganate index(CODMn)and ammonia nitrogen(NH3-N)as the research subjects,the pollution degradation coeffi-cients of typical sections of main canal of Middle Route of South-to-North Water Diversion Project were determined using in-door experimental simulation methods,and the simulated self-purification decay process was compared with the actual water quality changes.The results showed that:①The pollution degradation coefficients for the main canal were relatively low compared to natural rivers.The degradation coefficients of CODMn of Taocha,Zhengwan and Daanshe were 0.055 d-1,0.049 d-1 and 0.032 d-1 respectively,while the degradation coefficients of NH3-N were 0.003 d-1,0.003 d-1 and 0.009 d-1 respectively.Consider-ing that the actual components of the permanganate index were complex,the channel degradation coefficient may be lower than the simulation results.② The simulated self-purification decay process was significantly influenced by temperature and flow rate.Under different conditions,the permanganate index in the main channel decreased from 1.8 mg/L to a range of 0.228 to 1.042 mg/L,while ammonia nitrogen concentration decreased from 0.034 mg/L to a range of 0.026 to 0.030 mg/L.Due to the external inputs from algae,atmospheric deposition,and surface runoff,the permanganate index along the main channel ranged between 1.8 to 2.4 mg/L(in 2019),remaining relatively stable;while ammonia nitrogen concentrations ranged from 0.029 to 0.096 mg/L(in 2019),showing an increasing trend.Under ideal conditions,the self-purification process can reduce the average proportion of changes in permanganate index and ammonia nitrogen by81.81%and30.37%,respectively.The research results can provide a reference for further understanding the changes of water quality along the main canal of the Middle Route of South-to-North Water Diversion Project.关键词
污染物降解/自净过程/高锰酸盐指数/氨氮/降解系数/模拟实验/南水北调中线总干渠Key words
pollutant degradation/self-purification process/permanganate index/ammonia nitrogen/degradation coeffi-cient/simulation experiment/main canal of Middle Route of South-to-North Water Diversion Project分类
建筑与水利引用本文复制引用
肖新宗,郭芳,贾庆林,刘信勇,王超..南水北调中线总干渠污染物降解及自净能力研究[J].人民长江,2024,55(5):49-56,8.基金项目
湖北省自然科学基金项目(2022CFB342) （2022CFB342）
水利部重大科技项目(SKS-2022125) （SKS-2022125）
国家自然科学基金项目(U2040210) （U2040210）
