燕山地球关键带多环境介质中多环芳烃分布特征

Distribution characteristics of polycyclic aromatic hydrocarbons in multi-environmental media in Yanshan Earth Critical Zone

多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为环境中常见的持久性有机污染物,因其致癌、致突变、致畸和难降解的特性备受关注。地球关键带是维系地球生态系统功能和人类生存的关键区域,选取燕山地球关键带的雁栖湖站点,对地表水、表层土壤(0~10 cm)和地下水3种环境介质进行调查研究,旨在探索16种PAHs的分布情况。结果表明:1)地表水、土壤、地下水中的16种PAHs含量范围分别为9.78~2221.3 ng·L^(−1)、76.21~285.03μg·kg^(−1)、21.45~1521.13 ng·L^(−1),均值分别为548.42 ng·L^(−1)、195.77μg·kg^(−1)、492.54 ng·L^(−1),地表水中的平均浓度高于地下水;2)3种环境介质中PAHs分子质量分布呈现大体相似特征,具体表现为单体PAH中萘(Nap)占主导地位,2~3环低分子量PAHs占比大于4环,5~6环最低;3)地表水和地下水的PAHs质量分数占比基本相同,土壤与水体相比低分子质量PAHs占比略低,中高分子质量占比略高;4)利用主成分分析法对多环境介质中的PAHs进行源解析,发现环境中的PAHs主要来源于煤、石油、生物质的燃烧和交通污染,而大气沉降是主要的污染途径。总体来说,燕山地球关键带不同介质中存在不同程度的PAHs污染。

Polycyclic aromatic hydrocarbons(PAHs),as common persistent organic pollutants in the environment,have achieved significant attention due to their properties of carcinogenic,mutagenic,teratogenic,and difficult degradation.The critical zone of the earth(CZE)is a key area to maintain the sustaining ecological functions and human habitation.This study selected Yanqing Lake within the CZE,and investigated the surface water,surface soil(0~10 cm),and groundwater to explore the distribution characteristics of 16 types of PAHs.The results revealed that the concentrations of the 16 PAHs in surface water,soil,and groundwater were ranged from 9.78 to 2221.3 ng∙L^(−1),76.21 to 285.03μg∙kg^(−1),and 21.45 to 1521.13 ng∙L^(−1),respectively.The mean concentrations were 548.42 ng∙L^(−1),195.77μg∙kg^(−1),and 492.54 ng∙L^(−1),respectively,and the average concentration of the PAHs in surface water was higher than in groundwater.Besides,the molecular weight distributions of PAHs in three environmental media displayed similar trends.Specifically,naphthalene(Nap)was the dominant monomer PAHs.The proportion of 2-3 low molecular weight PAHs was greater than 4 rings PAHs,and the proportion of 5-6 rings PAHs was the lowest.In addition,the proportion of PAHs in surface water and groundwater was basically the same.Compared with water,soil,has less low molecular weight PAHs and more medium and high molecular weight PAHs.Last,the source analysis of PAHs in multiple environmental media was conducted by using principal component analysis method.It was found that PAHs in the environment mainly came from the combustion of coal,petroleum and biomass and traffic pollution,while atmospheric sedimentation was the main pathway for pollution.In general,various environmental mediums within the Yanshan Critical Zone exhibit varying degrees of PAHs contamination.