药物和个人护理用品对地下水污染的风险评价

为进一步明确污泥土地利用过程中新型有机污染物—药物和个人护理用品（PPCPs）对地下水污染的风险，采用数学模型初步预测和评价了29种PPCPs在砂土和壤土2种介质条件下对地下水污染的风险。结果表明：砂土条件下，环丙沙星、氧氟沙星、土霉素、诺氟沙星和咖啡因等5种PPCPs的风险指数大于1，具有高地下水污染风险，其中，除咖啡因外，其余4种PPCPs均为抗生素类药物，应加强其在地下水中的监测和防控。壤土条件下，29种PPCPs对地下水均表现为低污染风险。吸附强度是影响PPCPs对地下水污染风险的最主要因素。PPCPs在包气带中的半衰期、有机碳-水分配系数、土壤密度、有机碳含量、含有机质的上层土壤层厚度是模型主要的敏感参数。不确定性分析显示，PPCPs的有机碳-水分配系数和其在包气带中的半衰期的改变对地下水污染风险评价结果影响较大。验证表明，地下水污染风险指数越大的PPCPs在地下水中的检出率也越高，说明评价结果具有一定的合理性。今后应加强对PPCPs降解产物、地下水中安全浓度值、共存PPCPs相互作用及介质非均质性影响等方面的研究，以便更加精确地评价PPCPs对地下水污染的风险。

Groundwater pollution risk evaluation of pharmaceuticals and personal care products in land application of sludge

In order to further clarify the groundwater pollution risk of the pharmaceutical and personal care products (PPCPs), also known as emerging organic contaminants, in land application of sludge, groundwater pollution risks of 29 PPCPs under sand and loam soil conditions are primarily evaluated using a mathematical model. The results show that ciprofloxacin, ofloxacin, oxytetracycline, norfloxacin and caffeine have risk index values higher than 1 under sand soil conditions, indicating high groundwater pollution risks. Except caffeine, all the other 4 PPCPs with high groundwater pollution risks are antibiotics, which need to be further monitored and controlled in groundwater. Under loam soil conditions, all the 29 PPCPs show low groundwater pollution risks. Sorption is the main factor affecting the groundwater pollution risk of PPCPs. Sensitivity analyses indicate that the half-life of PPCPs in soil, organic carbon partition coefficient, soil density, organic carbon content and depth of the zone with organic matter are the key parameters affecting the model output. Uncertainty analyses show that changes in the organic carbon partition coefficient and half-life of PPCPs in soil have great impact on groundwater pollution risks. Test and verification show that PPCPs with higher groundwater pollution risk index values had higher detection rates in groundwater, indicating that the evaluation results are reliable. Further researches on degradation products of PPCPs, their safe levels in groundwater, interactions between coexisting PPCPs and medium heterogeneity effects should be strengthened in order to evaluate the groundwater pollution risk of PPCPs with reasonable accuracy.