ABSTRACT

The UV/chlorination of three prescription drugs, sulfamethazine (SMZ), gemfibrozil (GEM) and antipyrine (ANT) were studied by the investigation of kinetics, transformation products and combined toxicological assessment. The degradation followed pseudo-first-order kinetics, with half-lives significantly affected by chlorine dosage, without being greatly influenced by pH value and bromide concentration. Based on the Frontier Orbital Theory, the structures of products by hydroxylation or chlorine substitution were proposed and the transformation pathways were introduced, with two, two and one never-before-reported products identified for SMZ, GEM and ANT, respectively. Compared to the results of the experiments with artificial water sample, the degradation kinetics of the three prescription drugs was observed with a prolonged half-lives in both Yangtze River and Taihu Lake water, suggesting that aromatic containing transformation products (TPs) may also exist in UV/chlorine treated natural waters. The results of combined toxicity on E. coli showed that the antagonism effect predominated in most binary and ternary combinations. However, the synergistic toxicity of combinations at low concentrations of prescription drugs subjected to UV/chlorine should be cautioned, which was more close to the natural concentration of prescription drugs in waters.

摘要

通过动力学、转化产物和联合毒理学评估研究了三种处方药磺胺二甲嘧啶 (SMZ)、吉非罗齐 (GEM) 和安替比林 (ANT) 的紫外/氯化作用。降解遵循准一级动力学，半衰期受氯剂量的显着影响，而不受 pH 值和溴化物浓度的显着影响。基于前沿轨道理论，提出了羟基化或氯取代产物的结构，并介绍了转化途径，分别确定了SMZ、GEM和ANT的两种、两种和一种从未报道过的产物。与人工水样的实验结果相比，三种处方药的降解动力学在长江和太湖水中都观察到了延长的半衰期，这表明含有芳香烃的转化产物（TPs）也可能存在于紫外线/氯处理的天然水中。综合毒性结果大肠杆菌表明拮抗作用在大多数二元和三元组合中占主导地位。然而，应注意低浓度处方药在紫外线/氯作用下的组合的协同毒性，这更接近于水中处方药的自然浓度。