滹沱河石家庄段浅层地下水回补过程中磺胺类抗生素污染特征及风险评价

Pollution characteristics and risk assessment of sulfonamide antibiotics during shallow groundwater recharge in the Shijiazhuang section of the Hutuo River

为识别地下水回补过程中磺胺类抗生素(SAs)的污染特征及风险水平,于2020—2021年分2期采集滹沱河补水沿线16口浅层监测井的地下水样品,采用固相萃取-超高效液相色谱串联质谱法,测定分析地下水中20种SAs的浓度水平及分布特征,并利用风险熵值法进行生态及人体健康风险评价。结果表明,地下水中SAs总体污染程度较低,回补初期地下水中共检出7种SAs,按检出率大小依次为磺胺甲恶唑(93.75%)、磺胺嘧啶(37.50%)、磺胺氯哒嗪(18.75%)、磺胺吡啶(18.75%)、磺胺甲氧嘧啶(6.25%)、磺胺脒(6.25%)、磺胺醋酰(6.25%),平均检出浓度最高的为磺胺嘧啶(29 ng/L)和磺胺甲恶唑(9.2 ng/L)。在优质南水北调水回补的混合稀释作用下,地下水中SAs检出率和检出浓度呈明显下降趋势。历史污水处理厂排放及农业畜禽养殖污染是造成局部区域下水中SAs污染的主要原因。地下水中磺胺甲恶唑和磺胺嘧啶在回补初期属于中等生态风险,且磺胺嘧啶对人体健康具有中等风险。回补后期各SAs评价均无明显生态风险和健康风险。

In order to identify the pollution characteristics,ecological risk and health risk of sulfa antibiotics(SAs)in groundwater during the Hutuo River recharge process,sixteen shallow groundwater samples were collected twice along the Hutuo River bank from October 2020 to October 2021.The concentrations and distribution characteristics of 20 SAs were determined using solid-phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry.The results showed that the overall pollution level of SAs in groundwater was relatively low,and only 7 of the 20 SAs were detected in groundwater during the initial recharge period.The concentration of different SAs followed the order of characteristics:sulfametoxydiazine(93.75%),sulfadiazine(37.50%),sulfachlorpyridazine(18.75%),sulfapyridine(18.75%),sulfamonomethoxine(6.25%),sulfaguanidine(6.25%),sulfacetamide(6.25%).The highest average detection concentration SAs were sulfadiazine(29 ng/L)and sulfametoxydiazine(9.2 ng/L).Due to the mixed dilution effect of high-quality South-to-North Water Diversion water,the SAs detection frequency and average detection concentration declined gradually during the groundwater recharge.The historical pollution of sewage treatment plants and agricultural livestock and poultry in this area were the leading causes of SAs pollution in groundwater.The ecological and health risk assessment results indicated that the sulfametoxydiazine and sulfadiazine were medium ecological risks,and the sulfadiazine posed a moderate risk to human health.All SAs showed no obvious ecological risk and health risk in groundwater in the later period of the recharge process.