苏南地区农田表层土壤中多环芳烃和酞酸酯的污染特征及来源

Pollution Characteristics and Sources of Polycyclic Aromatic Hydrocarbons and Phthalic Acid Esters in Agricultural Surface Soil from the Southern Jiangsu Province, China

采用气相色谱质谱(GC-MS)法测定了苏南地区13个农田表层土壤样品中的多环芳烃(PAHs)和酞酸酯(PAEs)污染物,分析比较了不同区域农田表层土壤,尤其是来自钢铁企业周边的表层土壤中PAHs和PAEs的污染特征及其来源。结果表明,苏南地区农田土壤中总PAHs和总PAEs的浓度分别在147～40300μg·kg-1和0.575～762μg·kg-1之间,其中钢铁厂周边的平均浓度分别为6130μg·kg-1和47.4μg·kg-1。土壤样品中苯并(a)芘的浓度与总PAHs的浓度显著相关,高分子量PAHs在钢铁厂周边表土中含量较高,钢铁冶炼焦化和烧结等工序是其污染来源。酞酸正丁酯(DBP)和酞酸乙基己基酯是苏南地区农田土壤中含量最高的两种PAEs类物质,钢铁厂周边有较高的DBP检出可能与炼钢、冷轧和炼铁等工序有关。本研究将为经济高速发展地区农田土壤环境质量评价、农产品安全生产及土壤污染防治对策的制定提供科学依据。

Polycyclic aromatic hydrocarbons（PAHs） and phthalic acid esters（PAEs） are ubiquitous in the environment. They were the key pollutants of the national survey of soil pollution. The Southern Jiangsu Province is the main part of the Yangtze River Delta, which was one of the most rapidly developing areas not only in China but also in the world. Agricultural pollution in the Southern Jiangsu Province is more concerned with the economic development. In this study, three cities including Suzhou, Wuxi, and Nantong in the Southern Jiangsu Province were selected for the determination of PAHs and PAEs. Thirteen agricultural surface soil samples, including five samples from an iron and steel factory were collected. The pollution characteristics and potential sources of PAHs and PAEs were investigated. The total PAHs and PAEs concentrations varied from 147 to 40 300 μg·kg-1, and from 0.575 to 762 μg·kg-1, respectively. Concentration of benzo[a] pyrene and the total PAHs of the surface soil was significantly correlated. Di-n-butyl phthalate（DBP） and di[2-ethylhexyl] phthalate were the predominant PAEs in the soil samples. The average PAHs and PAEs concentrations of soil nearby the iron and steel factory were 6 130 μg·kg-1 and 47.4 μg·kg-1. Coking, sintering, and steel making processes were considered the potential sources of the high molecular weight PAHs and DBP. This study described the PAHs and PAEs concentrations, distribution patterns, and potential sources in one of the most rapidly developing areas in China. The results of this study should facilitate the development of soil environmental evaluation and safe food management practices in rapidly developing areas.