再生水回灌过程中典型磺胺类抗生素的行为特性研究

发布时间：2018-08-26 17:13

【摘要】：我国是一个严重缺水的国家,污水的再生利用已成为我国解决水资源短缺的重要战略,再生水补充涵养地下水就是途径之一。近年来,再生水中含有的微量抗生素可能会引起地下水污染问题,已经引起了越来越多的关注。因而亟需针对地下水回灌过程中抗生素的迁移转化特征进行研究,其成果对于防止地下水污染、保护地下水源具有重要的指导意义。论文选取两种典型的磺胺类抗生素——磺胺甲恶唑(SMZ)和甲氧苄胺嘧啶(TMP),建立高效灵敏的检测方法,通过室外采样调查目标抗生素在再生水回灌场地的分布特征,通过室内静态实验研究其在回灌区域底泥和包气带介质中的吸附-解吸作用,在土壤沉积物和再生水中的生物降解作用,结合室内动态实验揭示磺胺类抗生素在回灌场地土壤介质中的迁移转化规律,为评价其风险提供科学依据。通过优化超高效液相色谱的梯度洗脱程序、质谱条件和土壤提取方式,建立能同时检测SMZ和TMP的磺胺类抗生素UPLC/MS/MS检测方法,SMZ和TMP的检出限分别达到了0.4μg/L和0.3μg/L.对北京市潮白河再生水回灌场地三个断面进行检测,再生水中SMZ和TMP的检出率均为100%,平均浓度SMZTMP。SMZ和TMP在底泥和包气带介质中的吸附解吸研究,发现单溶质体系中SMZ和TMP在底泥中的吸附要强于包气带介质,土壤有机质含量越高吸附作用越强。双溶质体系中,TMP的存在抑制SMZ的吸附,而SMZ的存在能促进TMP的吸附作用。SMZ和TMP在底泥、包气带介质和再生水中的降解研究,发现无灭菌组中SMZ和TMP的降解均符合一级动力学。无灭菌组的半衰期要明显短于灭菌组。构建土柱模拟实验,发现连续回灌后土柱的渗透速率不断下降,最终保持稳定。通过静态和动态实验获取参数,构建抗生素在土柱中迁移转化的一维方程,发现SMZ和TMP在土柱1中的预测穿透时间分别需要69d和1858d,在实际回灌15d中未检测到SMZ和TMP的浓度。SMZ和TMP在土柱2中的预测穿透时间分别为0.95d和15.3d,在实际检测中SMZ的穿透时间比理论时间早,为5h,TMP在回灌期间内未能检测到浓度。
[Abstract]:China is a country with serious water shortage. The reuse of sewage has become an important strategy to solve the shortage of water resources. Reclaimed water supply and conservation of groundwater is one of the ways. In recent years, trace antibiotics in recycled water may cause groundwater pollution, which has attracted more and more attention. Therefore, it is urgent to study the characteristics of antibiotic migration and transformation in the process of groundwater recharge, which has important guiding significance for preventing groundwater pollution and protecting groundwater source. In this paper, two typical sulfamethoxazole (SMZ) and methoxybenzylamine (TMP),) were selected to establish an efficient and sensitive detection method, and the distribution characteristics of target antibiotics in reclaimed water recharge site were investigated by outdoor sampling. The adsorption and desorption in sediment and aeration zone and biodegradation in soil sediment and reclaimed water were studied by static experiments in laboratory. Combined with indoor dynamic experiments, the migration and transformation of sulfanilamide antibiotics in soil media of recharge site were revealed, which provided a scientific basis for evaluating the risk of sulfanilamide antibiotics. By optimizing the gradient elution procedure of ultra-high performance liquid chromatography (HPLC), mass spectrometry conditions and soil extraction methods, the detection limits of sulfanilamide antibiotics (UPLC/MS/MS) for simultaneous detection of SMZ and TMP were 0.4 渭 g / L and 0.3 渭 g / L, respectively. The detection limits of UPLC/MS/MS and TMP were 0.4 渭 g / L and 0.3 渭 g / L, respectively. Three sections of reclaimed water recharge site of Chaobai River in Beijing were examined. The detectable rates of SMZ and TMP in reclaimed water were 100. The adsorption and desorption of SMZTMP.SMZ and TMP in sediment and aeration zone were studied. It was found that the adsorption of SMZ and TMP in the sediment was stronger than that in the aerated medium, and the higher the content of soil organic matter was, the stronger the adsorption was. The presence of TMP in the double solute system inhibited the adsorption of SMZ, while the presence of SMZ promoted the degradation of TMP in sediment, aeration zone medium and regenerated water. It was found that the degradation of SMZ and TMP in sterilized group was in accordance with first-order kinetics. The half-life of sterilizing group was shorter than that of sterilizing group. It is found that the permeation rate of soil column decreases continuously after continuous reinjection, and finally remains stable. The one-dimensional equation of antibiotic migration and transformation in soil column was established by static and dynamic experiments. It was found that the predicted penetration time of SMZ and TMP in soil column 1 required 69 days and 1858 days, respectively. The predicted penetration time of SMZ and TMP in soil column 2 was 0.95d and 15.3d respectively, and the predicted penetration time of SMZ and TMP was 0.95d and 15.3d respectively. The penetration time is earlier than the theoretical time, The concentration of TMP was not detected during the period of recharge.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;X523

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