城区第四系沉积柱中抗生素的垂向分布特征及环境影响因素

Characteristics of Vertical Distribution and Environmental Factors of Antibiotics in Quaternary Sedimentary Column in Urban Areas

抗生素从地表向地下迁移时,容易通过水-岩相互作用残留于沉积物中,给地下水带来二次释放的风险.为探究抗生素的垂向分布特征和环境影响因子,于医院附近钻孔并分层采集了5个30 m第四系沉积柱,测试分析了5大类抗生素和磺胺代谢物.结果表明:①沉积物中抗生素含量范围为3.05~107.03μg·kg^(-1),除洛美沙星外,其他所有目标抗生素均有检出,其中氧氟沙星和土霉素是研究区最主要的抗生素;②抗生素在垂向上并不呈现严格的下降趋势,而是随着岩性层位的变化而变化;③抗生素主要赋存在黏粒沉积物中,并随地下水位的波动而变化;④抗生素与环境因子的冗余分析结果表明,pH和TOC通过影响沉积物对抗生素的吸附作用来控制抗生素的迁移转化.医院废水渗漏对地下环境带来的抗生素污染的风险应引起重视.

Antibiotics easily remain in sediments after migrating from the surface to the subsurface due to water-rock interactions,posing a risk of secondary release to groundwater.To investigate the vertical distribution characteristics and environmental impact factors of antibiotics,five 30 m quaternary sediment columns were drilled and stratified near the hospital,and five major classes of antibiotics and sulfonamide metabolites were tested and analyzed.The results showed that:①the antibiotic content in the sediments ranged from 3.05 to 107.03μg·kg^(-1),and all of the target antibiotics were detected except lomefloxacin,of which ofloxacin and oxytetracycline were the most important antibiotics in the study area.②The antibiotics did not show a strict downward trend in the vertical direction but varied with the lithological stratification.③Antibiotics were primarily deposited in the clay layer and varied with the fluctuation of the groundwater level.④The results of redundancy analysis between antibiotics and environmental factors suggested that pH and TOC controlled the fate and transformation of antibiotics through influencing the adsorption of antibiotics by sediments.The risk of antibiotic contamination from hospital wastewater seepage into the subsurface environment should be taken seriously.