不同类型含水层中的抗生素污染特征及成因研究

Study on the characteristics and mechanism of antibiotic pollution in different aquifers

抗生素在含水层中构成的风险已经引起广泛关注。为探明抗生素在不同类型含水层中的污染特征及主控因素,识别含水层中抗生素污染的指示因子,本研究在松嫩平原、华北平原和西南岩溶区共采集309组样品,利用超高效液相色谱串联质谱联用仪(UPLC-MS/MS)分析了35种抗生素含量。结果表明:(1)35种抗生素均有检出,岩溶含水层(34种)和华北孔隙含水层(32种)主要检出喹诺酮类和大环内酯类抗生素,东北孔隙含水层仅检出以红霉素为主的6种抗生素。在孔隙含水层中,松嫩平原整体呈低浓度污染(中位数为2.07ng/L,检出率为100%),华北平原污染偏重(11.76ng/L)但空间占比仅为49%,而岩溶含水层中的抗生素污染整体表现为浓度高,面积广(37.5ng/L,87%);(2)岩溶与孔隙含水层抗生素污染特征差异归因于水文地质条件的差异(开放程度和渗透性),而抗生素的排放强度是导致不同地区孔隙含水层差异的主要原因;(3)基于相关系数的聚类分析识别了不同类型含水层中抗生素的指示因子,TOC能有效指示孔隙含水层的抗生素污染,同时NH^(+)_(4)和SO^(2-)_(4)揭示了人类活动与抗生素的正相关关系,地下水性质参数是岩溶含水层中可靠的抗生素污染指示因子,表现为在偏碱性和呈氧化环境的岩溶水中抗生素浓度偏低。研究结果可为地下水新污染的区域防治提供科学依据。

The risk posed by antibiotics in various aquifers has attracted wide attention.This study investigated the pollution characteristics and controlling factors of antibiotics in different types of aquifers,and identified the indicator factors of antibiotic pollution in aquifers based on a total of 309 sets of samples from Songnen Plain,North China Plain,and Southwest Karst area.The concentrations of 35 antibiotics were analyzed using ultra-high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The results show that:(1)all 35 antibiotics were detected,with karst aquifers(34 types)and North China porous aquifers(32 types)mainly containing quinolones and macrolide antibiotics,while only 6 types of antibiotics,mainly erythromycin,were detected in Northeast porous aquifers.In porous aquifers,the overall pollution in Northeast China is characterized by low concentrations(median=2.07 ng/L,detection rate=100%),while the pollution in North China is relatively heavy(11.76 ng/L),accounting for 49%of the spatial distribution.In the karst aquifers,the antibiotic pollution is characterized by high concentrations(37.5 ng/L)and a large spatial extent(87%).(2)The characteristic differences in antibiotic pollution between karst and porous aquifers are attributed to the hydrogeological conditions(openness and permeability),while the emission intensity of antibiotics is the primary reason for the differences between porous aquifers in different regions.(3)Cluster analysis based on correlation coefficients identified the indicator factors of antibiotics in different types of aquifers.Total organic carbon(TOC)NH+4 SO2-4can effectively indicate the antibiotic pollution in porous aquifers,while and reveal a positive correlation between human activities and antibiotics.Groundwater property parameters are reliable indicators of antibiotic pollution in karst aquifers,with lower antibiotic concentrations observed in alkaline and oxidizing karst water.The research results can provide scientific basis for regional prevention and control of emerging organic contaminants in groundwater.