绵竹市典型河流水污染特征及水质评价

于2017年3月、8月和11月,每月月初对绵竹市两条典型河流(绵远河与马尾河)5个监测断面表层水样进行采集,选取8个水质指标进行因子特征分析,并采用单因子评价法、综合污染指数法和主成分分析法对河流水质进行评价。两条河流水体呈弱碱性。单因子评价法表明,总磷(TP)为两条河流水质的主要限制因子。综合污染指数法表明,除马尾河中间断面外,其他水质状况均为轻度污染,且枯水期水质最差。主要污染因子为氨氮(NH3-N)、TP和高锰酸盐指数(CODMn)。主成分分析表明,断面水质主要受砷(As)、溶解氧(DO)、CODMn、氟离子(F^-)、TP和NH3-N等多个因子影响,出境断面水质优于中间断面。3种方法结合定性和定量评价,评价结论不一致,所以应用多种方法来评价水质具有重要意义。

Pollution characterization and water quality assessment of typical rivers of Mianzhu City

Water samples were collected in two typical rivers (Mianyuan River and Mawei River) of Mianzhu city in March,August,November of 2017 respectively.Factor characteristics analysis were performed using pH,dissolved oxygen (DO),ammonia nitrogen (NH3-N),total phosphorus (TP),permanganate index (CODMn),Arsenic (As),oil (TPH) and fluorine ions (F^-) as the physicochemical factors.Single-factor assessment method,comprehensive pollution index method and principal component analysis method were applied to evaluate the water quality of the rivers.The water body presented weak alkalinity.The single-factor assessment indicated that the first restrictive factors of water quality was TP.The results of comprehensive pollution index assessment showed that the water quality was in a mild pollution condition except for one sample section of Mawei River,with worse water quality in dry season period than in other two periods.NH3-N,TP and CODMn were the main pollution factors.The principal component analysis method showed that indexes such as As、DO、CODMn、F^-、TP and NH3-N greatly influenced the water quality of the rivers.The outbound section water quality was better than intermediate section.The three methods were a combination of qualitative and quantitative evaluation.The results of each method were not identical with each other.So it is very important to work on water quality assessment using various methods.