多环芳烃在不同灌区土壤剖面的分布特征研究

文章在不同类型灌溉用水的三个典型灌区进行土壤精细剖面钻探采样分析,研究16种优控多环芳烃在土壤剖面的分布特征和不同灌溉条件对土壤质量的影响。结果表明:表土是多环芳烃的主要累积层位,污灌区、再生水灌区、清灌区表土的多环芳烃总量分别为726、200、34μg/kg,说明长期进行污水和再生水灌溉均会造成不同程度的土壤污染;受多环芳烃自身理化性质的影响,低环的多环芳烃容易向土壤剖面的深部迁移,在表土以下的层位占绝对优势分布,高环的多环芳烃迁移性很弱,基本只在表层有检出;通过对各灌区剖面的典型多环芳烃含量和土壤理化指标进行相关分析和回归分析,得出TOC是多环芳烃在土壤剖面垂向迁移的主要影响因素。

Distribution Characteristics of PAHs in Soil Profiles of Different Irrigation Areas

Through sampling and analyzing soil profile samples (0～5.5m)from 3 typical irrigation areas,influence on soil quality of different irrigation conditions and PAHs distribution characteristics in soil profiles were studied. Results showed that surface soil was major accumulation stratum of PAHs. Total concentrations of 16 PAHs in surface soil of sewage,reclaimed water and groundwater irrigation area were 726,200,34μg/kg respectively,which illustrated that long-term sewage and reclaimed water irrigation may lead to soil pollution at different degrees. Influenced by physico-chemical properties of PAHs, low-ring PAHs could reach deeper soil layers and showed absolute distribution dominance in soil profiles,high-ring PAHs which have lower migration capability were only detected in surface soil basically. According to correlation analysis and regression analysis between PAHs concentrations and soil physico-chemical properties,TOC of soil is the key factor influencing vertical migration of PAHs in soil profiles.