滦河上游流域水质特征及污染源解析

Analysis of Water Quality Characteristics and Pollution Sources in the Upper Reaches of Luanhe River Basin

滦河位于京津冀水源涵养功能区的核心区域,精准分析其水质演变特征及污染来源,对于流域水污染防治具有重要意义。通过对滦河上游流域19个监测断面、8个水质指标进行监测,采用对数型幂函数普适指数公式进行富营养化评价,运用主成分分析法结合多元线性回归源解析模型确定污染来源。结果表明:滦河上游流域属于弱碱性水体,大部分水体处于过饱和状态,高锰酸盐指数(CODMn)的数值丰水期变幅相对较大,年际超标率为7%,总氮(TN)浓度整体远大于氨氮(NH+4-N)浓度,且TN年际超标率高达94%,枯水期全样本超标,说明水体氮素污染较为严重。总磷(TP)全年均值为0.09 mg/L,年际超标11%,整体浓度相对较低。滦河上流流域全监测区域处于富营养、中营养以及重富营养等不同程度富营养化,且处于富营养状态区域占比高达78.94%。其中丰水期富营养化程度较为严重,重富营养化均出现于丰水期。根据污染源贡献率解析可知,对水体TN、NH+4-N贡献最大的是农业非点源污染,支流还受到畜禽养殖及生活污水影响,干流TN有一部分潜在污染来源,TP和CODMn主要来自城市面源污染,五日生化需氧量(BOD5)支流主要来自畜禽养殖、生活污水,干流区域来源相对较为复杂只受潜在污染源影响。

The Luanhe River is located in the core area of the Beijing-Tianjin-Hebei water conservation function area.Accurately analyzing the water quality evolution characteristics and the pollution sources is of great significance for the prevention and control of water pollution in the basin.19 monitoring sections and 8 water quality indexes in the upper reaches of Luanhe River Basin were monitored.The eutrophication was evaluated by using the universal index formula of logarithmic power function.And principal component analysis combined with multivariable linear regression source analysis model was used to determine the pollution sources.The results show that the upper reaches of Luanhe River Basin is a weakly alkaline water body,and most of the water body is in a state of suoversaturation.The permanganate index(CODMn)value shows a relatively large variation of in the high water period,with the inter-annual exceeding rate is 7%.The total nitrogen(TN)concentration is much higher than NH+4-N concentration on the whole,the inter-annual exceeding rate of TN is as high as 94%,and all the samples exceeded in withered water period,indicating that nitrogen pollution is serious in water.The annual average of total phosphorus(TP)is 0.09 mg/L,and the inter-annual exceeding rate is 11%.The overall concentration of TP is relatively low.The whole monitoring area of the upper reaches of the Luanhe River Basin is in different degrees of eutrophication such as eutrophication,medium eutrophication and heavy eutrophication,among which the proportion of the area in eutrophication state is as high as 78.94%.The degree of eutrophication is more serious in the high water period,and all the heavy eutrophication occures in this period.According to the analysis of the contribution rate of pollution sources,the agricultural non-point source pollution is the most contribution to TN and NH+4-N of water,and the tributaries are also affected by livestock and poultry breeding and domestic sewage,TN of the main stream has some potential pollution sources.TP and CODMn are mainly from urban non-point source pollution,and the biochemical oxygen demand after 5 days(BOD5)of the tributaries are mainly from livestock and poultry breeding and domestic sewage,the sources in the main stream are relatively complex and only affected by potential sources.