永定河怀来段水质污染特征及污染源解析

Water Pollution Characteristics and Pollution Source of Yongdinghe River in Huailai

通过对永定河怀来段枯水期支干流进行4次采样,对11个指标进行监测,采用单因子水质标识指数和综合水质标识指数评价法对水质污染特征进行了综合评价,运用主成分分析法和聚类分析法,确定了流域主要污染因子及区域水质空间变化特征,对不同支干流污染源进行解析。结果表明:永定河怀来段12个监测断面均未达到Ⅲ类水体标准限值,仅p H、DO指标达标,且氮磷超标最为严重,干流综合水质标识指数最高为5.554,支流ZL8最高为7.254。COD、TN和NO_3^--N为第一主成分,TP、PO_4^(3-)-P和NO_2^--N为第二主成分,DO和TOC为第三主成分。永定河干流水质优于东沙河水质。对各监测断面聚类分析后,将永定河怀来段水域根据水质大致划分为2个区域,其中干流监测断面都在同一类,湿地水质与干流水质有明显差异。在二级支流中,冬季农田退水依次进入鱼塘湿地、芦苇湿地和芦苇沟后,TN、NO_3^--N和NO_2^--N的去除效率分别为51.11%、42.27%和72.88%,而NH_3-N、TP有所增加。永定河流域污染主要来自于农业面源污染、污水处理厂出水点源污染和农村生活污水排放等。

Through to the Yongding section of the Huailai River in dry season branch flow sampling 4 times, monitoring of the 11 indexes, the single factor water quality identification index and comprehensive water quality identification index evaluation method on water pollution characteristics of comprehensive evaluation, using principal component analysis and cluster analysis, determine the characteristics of the main space of water pollution factors and the area change basin, analyzing different stem flow pollution sources. The results showed that the 12 monitoring sections in the Huailai section of Yongding river did not reach the standard limit of class III water. Only p H and DO were up to the standard, and the highest level of nitrogen and phosphorus exceeded the standard. The WQI index of the mainstream was the highest and the tributary ZL8 was the highest of 7.254.COD, TN and NO_3^--N are the first principal components, and TP, PO_4^(3-)-P and NO_2^--N are second principal components, and DO and TOC are the third principal components. The water quality of the main stream of Yongding river is better than that of East Shahe. After clustering analysis of each monitoring section, the waters of Huailai section of Yongding River can be roughly divided into two regions according to the water quality. The main stream monitoring sections are all in the same category, and the water quality of the wetland is obviously different from that of the main stream. In the two stage tributaries, the removal efficiency of TN, NO_3^--N and NO_2^--N was 51.11%, 42.27% and72.88%, respectively, while NH3-N and TP increased. The pollution of Yongding River Basin mainly comes from agricultural non-point source pollution, sewage treatment plant effluent point source pollution and rural domestic sewage discharge.