闽江河口洲滩表层沉积物中多环芳烃的含量、来源和生态风险

Contents,Sources and Ecological Risk of Polycyclic Aromatic Hydrocarbons in Surface Sediments of Minjiang River Estuary Beaches

多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为典型的持久性有机污染物,广泛存在于环境中。河口湿地的沉积物能吸收和累积环境中的多环芳烃,研究沉积物中多环芳烃的含量、污染水平和来源,对开展河口海岸区保护、环境管理和污染物控制具有重要意义。在福州市闽江河口的塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩布设了23个采样点,于2020年10月18日至20日,采集了表层(0~5 cm深度)沉积物样品,测定了16种多环芳烃类化合物的含量,分析了表层沉积物中多环芳烃的来源、污染水平和生态风险。研究结果表明,闽江河口塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中多环芳烃总含量的范围为15.85~381.52 ng/g,塔礁洲和道庆洲表层沉积物中多环芳烃的含量明显大于蝙蝠洲和鳝鱼滩;塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中的多环芳烃以高环数多环芳烃为主,其主要来源于周围工业废水排放、化石燃料燃烧、交通工具尾气排放、农业生物质燃烧,船舶运输过程中的石油泄漏和燃料不完全燃烧是表层沉积物中少量低环数多环芳烃的主要来源;道庆洲表层沉积物被多环芳烃轻微污染;塔礁洲、道庆洲、蝙蝠洲和鳝鱼滩表层沉积物中5种多环芳烃类化合物的含量对周围环境有中等生态风险。

Polycyclic aromatic hydrocarbons(PAHs)are typical persistent organic pollutants and widely exist in the environment.The sediments can absorb and accumulate polycyclic aromatic hydrocarbons in the environment.It is of great significance to study the contents,pollution levels and sources of polycyclic aromatic hydrocarbons in the sediments for the protection,environmental management and pollutant control of estuarine and coastal areas.In the Minjiang River Estuary beaches,including Tajiaozhou,Daoqingzhou,Bianfuzhou and Shanyutan beaches,that along the Minjiang River Basin in Fuzhou city,23 sampling points were selected and the surface sediment samples(0-5 cm depth)were collected in the sites on October 18 to20,2020.The contents of 16 kinds of polycyclic aromatic hydrocarbons compounds were determined,and their sources were analyzed,and the pollution level and the ecological risk of polycyclic aromatic hydrocarbons in surface sediments were evaluated.The results showed that the total content of polycyclic aromatic hydrocarbons in the surface sediments of Tajiaozhou,Daoqingzhou,Bianfuzhou and Shan yutan beaches along the Minjiang River estuary ranged from 15.85 ng/g to 381.52 ng/g,and the contents of polycyclic aromatic hydrocarbons in the surface sediments of Tajiaozhou and Daoqingzhou beaches were significantly higher than those of Bianfuzhou and Shanyutan beaches.The polycyclic aromatic hydrocarbons in the surface sediments of Tajiaozhou and Daoqingzhou and Shanyutan beaches were characterized mainly by high cyclic aromatic numbers,which were mainly derived from the surrounding industrial wastewater discharge,fossil fuel combustion,traffic exhaust emission and biomass combustion in agriculture and aquaculture reclamation process.Oil leakage and incomplete fuel combustion during ship transport process were the main sources of low cyclic aromatic numbers in the surface sediments.The surface sediments of Daoqingzhou beach were slightly polluted by polycyclic aromatic hydrocarbons.The contents of 5 kinds of polycyclic aromatic hydrocarbons in the surface sediments of Tajiaozhou,Daoqingzhou,Bianfuzhou and Shanyutan beaches had medium ecological risks to the surrounding environment.