黄河包头段冻融过程中PAHs的分布特征及来源解析

Distribution and Sources of PAHs in the Baotou Section of the Yellow River during Freezing-Thawing Process

为研究黄河包头段冻融过程中PAHs（多环芳烃）的分布特征及来源,分别于2012—2014年流凌期、封河期及融冰期采集黄河包头段干流水相及冰相样品,分析该河段PAHs的时空分布特征,并通过主成分分析法探究污染物的来源.结果表明,水相中共检测出11种PAHs,ρ（∑_（11）PAHs）的范围为6.58～222.37 ng/L,平均值为61.48 ng/L,其中Fla（荧蒽）为最主要的污染物,部分组分在个别采样点超出了EPA882-Z-99-001中规定的标准限值;冰相中共检测出8种PAHs,ρ（∑_8PAHs）的范围为4.91～59.39 ng/L,平均值为27.17 ng/L,ρ（4环PAHs）所占比例最大.ρ（PAHs）在水相与冰相中沿程分布规律一致,S2、S5采样点较高,S4、S7采样点相对较低.水相冻融过程中,大部分采样点的ρ（PAHs）均在稳定封河时较高.水相冻融过程中原有7种PAHs反应的信息可由3个因子来代替,分别代表生活污水及工业污废水排放源、煤燃烧排放源及交通源的污染,方差累积贡献率达80.00%.

Ice and water samples were collected from 2012 to 2014 under freezing and flowing conditions from eight sites along the Baotou section of the Yellow River. Eleven different polycyclic aromatic hydrocarbons（ PAHs） were detected in 48 water samples,with fluoranthene dominating. The total PAHs concentrations ranged from 6. 58 to 222. 37 ng/L,with a mean value of 61. 48 ng/L. In the 12 ice samples taken,eight different,predominantly four-ringed,PAHs were detected. The total PAHs concentrations ranged from 4. 91 to59. 39 ng/L,with the mean value of 27. 17 ng/L. The spatial distributions of PAHs in both ice and water were significantly correlated,with the highest concentrations found at section 2,followed by section 5. Sections 2 and 5 were closest to most of the industrial point sources and wastewater outfalls. Principal component analysis was used to verify the reliability of the calculated PAHs ratios,and to determine potential sources. From the water samples collected,80. 00% of the variance could be explained by three components that were selected to represent coal combustion as the source of PAHs. Other components found in the samples indicated that PAHs in the Baotou section of the Yellow river were from the industrial wastewater and municipal sewage discharge,coal combustion and transportation sources.