三峡工程蓄水对澎溪河回水区COD_(Mn)、NH_3-N和TP综合衰减系数的影响  

Effect of the Three-Gorge Project impoundment on the COD_(Mn),NH_3-N and TP fall coefficients

作　　者：王晓青[1] 

机构地区：[1]重庆交通大学西南水运工程科学研究所,重庆400016

出　　处：《安全与环境学报》2015年第1期325-329,共5页Journal of Safety and Environment

摘　　要：三峡工程蓄水导致支流回水区水流缓滞,从而影响污染物的扩散、降解,使水质发生变化。为研究三峡调蓄水位的变化及其对污染物综合衰减系数的影响,以澎溪河回水区渠口至河口段为研究区域,根据水文和水质监测资料,采用DHI MIKE21的水动力模型和ECOlab水质模型进行计算。结果表明：蓄水前的天然状态下,CODMn、NH3-N和TP综合衰减系数分别为0.130-0.250 d^-1、0.110-0.180 d^-1和0.080-0.130 d^-1;蓄水后的调蓄状态下,CODMn、NH3-N和TP综合衰减系数分别为0.007-0.016 d^-1、0.006-0.015 d^-1和0.005-0.012 d^-1。可见三峡工程蓄水后,回水区污染物的综合衰减系数仅为蓄水前的1/20-1/10,需通过控制污染物的衰减速率以达到控制水体污染和水体富营养化的目的。The paper attempts to bring forward our study results of the effects of the Three-Gorge Project impoundment on the CODMn,NH3-N and TP fall coefficients. As is known,since the impoundment of the Three-Gorge reservoir,serious effects have been brought about on the hydrological conditions in the backwater areas,with the Pengxi river being one of the typical example. In hoping to control the water pollution and water eutrophication in the reservoir area,we think it necessary to study the changes of the pollutant fall coefficients. Thus,in proceeding with our research, we have studied the permanganate index（CODMn）,ammonia nitrogen（NH3-N） and the total phosphorus（TP） of the water quality during 2004-2010 with the backwater effects of the reservoir on the Pengxi river as a typical region.The results of our investigation and statistics have shown that the ranges of CODMn,NH3-N and TP concentrations turn to be 1. 4-4. 0 mg / L,0. 03-0. 57 mg / L and 0. 05-0. 16 mg / L respectively.In addition,the high organic pollutant concentrations are likely to take place mainly in the high-tide water period. Based on the water quality monitoring data,we have observed the changes of CODMn,NH3-N,TP fall coefficients before and after the reservoir impoundment in the Pengxi backwater area by using the MIKE21 HD and the ECOLab WQ simulation models. By choosing the statistical area within the distance of 53. 5 km of the Pengxi river in the range between the estuaries to Qukou section in Yunyang city and the main Yangtze reach of 6. 8 km in Shuangjiang city. We have also used the unstructured mesh with13 313 nodes and 20 782 statistical units in the 2D simulation models. The investigation results show that the ranges of CODMn,NH3-N and TP fall coefficients which are worked out at about0. 130-0. 250 d-1,0. 110-0. 180 d-1and 0. 080-0. 130 d-1respectively before the impoundment, and 0. 007-0. 016 d-1,0. 006-0. 015 d-1and 0. 005-0. 012 d-1respectively after the impoundment,with the pollutants fall coefficients after the impoundment b

关 键 词：环境学 三峡工程 澎溪河 高锰酸盐指数 氨氮 总磷 综合衰减系数 

分 类 号：X143[环境科学与工程—环境科学]