天津供水系统中抗生素分布变化特征与健康风险评价

通过采用固相萃取富集法和液相色谱质谱联用技术对天津市供水系统中净水厂和管网中的6类10种抗生素浓度水平进行了分析,研究了抗生素在各处理工艺单元后的变化特征,以及在管网中的分布迁移规律,并进行了健康风险评价.对不同处理工艺的A、B两水厂中抗生素的检测结果显示:采用传统处理工艺的A水厂出水中抗生素的质量浓度范围为0.96~126.43 ng·L~(-1),总去除率为-46.47%~45.10%,混凝工艺对抗生素物质的去除起主要作用;具有深度处理工艺的B水厂出水中抗生素的浓度为ND~72.27 ng·L~(-1),其中罗红霉素未检出,抗生素的去除效率为40.25%~70.33%,明显优于A水厂,紫外+氯消毒工艺对抗生素的去除最为明显.给水管网中抗生素浓度分析结果表明:10种抗生素中除罗红霉素检出率为75.0%外,其余均为100.0%.抗生素浓度范围为ND~348.99 ng·L~(-1),浓度随管段的延伸而逐渐降低,其衰减符合一级反应动力学模型.基于蒙特卡洛法对饮用水中抗生素的致癌风险和非致癌风险进行了评估,结果表明均处于可接受风险水平.

Distribution Characteristics and Health Risk Assessment of Antibiotics in the Water Supply System in Tianjin

Six groups of 10 antibiotics in the water plants and water supply network in Tianjin were sampled and analyzed by using solid phase extraction and high performance liquid chromatography-mass spectrometry. The concentrations of 10 antibiotics were detected in the water treatment process units, and the distribution, migration, and health risk assessment in the water supply networks were studied. The results of antibiotic determination in the water plants showed that the antibiotic concentrations were 0.96-126.43 ng·L^-1, and the removal efficiency was -46.47%-45.10% in plant A using traditional treatment processes. The coagulation treatment process was effective for the antibiotic removal in plant A. In plant B with an advanced treatment process, roxithromycin was not detected, and the concentration of other antibiotics was ND-72.27 ng·L^-1. The removal efficiency of the antibiotics was 40.25%-70.33% in plant B, which was remarkably higher than that in plant A. The results indicated the process of UV combined with chlorine disinfection played a major role in removing antibiotics in plant B. In addition, the antibiotic distribution in the water pipes indicated that the detection rate of roxithromycin was 75.0% and that for other antibiotics was 100.0%. The concentration of 10 antibiotics was ND-348.99 ng·L^-1 and decreased gradually with the increase of the transmission distance, which followed the first order reaction kinetics model. Based on the Monte Carlo method, the carcinogenic and non-carcinogenic health risks of antibiotics in drinking water were assessed. The results displayed that both were at an acceptable level of risk.