宁夏第三排水沟中PAHs的污染特征、来源解析及生态风险评估  

Pollution Characteristics,Source Analysis,and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Third Drain of Ningxia

作　　者：吴海娟 高礼[1] 李富娟 李凌云 郑兰香 WU Hai-juan;GAO Li;LI Fu-juan;LI Ling-yun;ZHENG Lan-xiang(China-Arab Joint International Research Laboratory for Featured Resources and Environmental Governance in Arid Region,School of Geography and Planning,Ningxia University,Yinchuan 750021,China;School of Ecological Environment,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学地理科学与规划学院,教育部中阿旱区特色资源与环境治理国际合作联合实验室,银川750021 [2]宁夏大学生态环境学院,银川750021

出　　处：《环境科学》2024年第9期5254-5263,共10页Environmental Science

基　　金：宁夏自然科学基金项目(2021AAC05004,2023AAC03055);宁夏回族自治区重点研发项目(2020BEB04008,2019BFG02032)。

摘　　要：为了明确宁夏第三排水沟中多环芳烃(PAHs)的污染特征、来源和生态风险,分别于2021年11月、2022年3月和7月采集排水沟水样,采用气相色谱-质谱法对16种PAHs进行了定量检测分析.结果表明,宁夏第三排水沟中ρ(ΣPAHs)范围为324.11~530.77 ng·L^(−1),平均值为414.73 ng·L^(−1).单体检出率均在90%以上,其中,二苯并[a,h]蒽的检出浓度最高,平均值为48.53 ng·L^(−1);其次为茚苯[1,2,3-cd]芘.与国内其它河流相比,宁夏第三排水沟中PAHs处于中等污染水平.ΣPAHs浓度和高环单体浓度在夏季显著高于冬季和春季.空间上,排水沟中ΣPAHs浓度平均值大小为:上游贺兰段>中游平罗段>下游惠农段.第三排水沟中PAHs组分占比大小为:高环(5~6环)>低环(2~3环)>中环(4环),5环PAHs组成占主导地位.运用正定矩阵因子分解(PMF)模型对PAHs的来源贡献进行了定量分析,结果表明,第三排水沟中PAHs主要来源于煤化工排放(27.36%)、交通排放(27.64%)、煤炭燃烧(26.85%)和石油化工排放(18.15%).生态风险评估结果表明,5种单体(苯并[a]蒽、苯并[b]荧蒽、苯并[ghi]苝、二苯并[a,h]蒽和茚苯[1,2,3-cd]芘)存在高风险,其余单体均处于中风险,需尽快采取控制措施.本研究可为宁夏入黄排水沟PAHs污染防控提供科学依据.This study aimed to investigate the contamination characteristics,sources,and ecological risks of polycyclic aromatic hydrocarbons(PAHs)in the Third Drain of Ningxia.Water samples were collected in November 2021,March 2022,and July 2022,respectively.A total of 16 priority PAHs were quantitatively detected using gas chromatography-mass spectrometry(GC-MS).The results showed thatρ(ΣPAHs)in the drain ranged from 324.11 to 530.77 ng·L^(−1),with an average value of 414.73 ng·L^(−1).The detection rate of each monomer was greater than 90%,and DaA had the highest concentration,with average values of 48.53 ng·L^(−1),followed by IcdP.Compared with those in other rivers in China,the PAH concentrations in the Third Drain of Ningxia showed a medium pollution level.The concentration ofΣPAHs and the high ring monomers were significantly higher in summer than that in spring and winter.On a spatial scale,the average concentration ofΣPAHs in the drain decreased in the order of upstream Helan section>midstream Pingluo section>downstream Huinong section.The proportion of PAHs was in the order of high rings(5-6 rings)>low rings(2-3 rings)>middle rings(4 rings),with 5 rings being dominant.Probabilistic matrix factorization(PMF)was used to quantitatively assess the source apportionment of PAHs.The results showed that coal chemical emissions,automobile exhaust emissions,coal combustion,and petrochemical emissions contributed 27.36%,27.64%,26.85%,and 18.15%,respectively.Ecological risk assessment showed that BaA,BbF,BghiP DaA,and IcdP had high risk,whereas other monomers exhibited moderate risk.Therefore,control measures should be taken as soon as possible.This study can provide a scientific basis for the prevention and control of PAH pollution in the drains flowing into the Yellow River of Ningxia.

关 键 词：多环芳烃(PAHs) 污染特征 来源解析 生态风险 第三排水沟 

分 类 号：X522[环境科学与工程—环境工程] X820.4