College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310027, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310027, China; School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200433, China.
J Hazard Mater. 2019 Mar 15;366:88-97. doi: 10.1016/j.jhazmat.2018.11.096. Epub 2018 Nov 24.
Sulfadiazine (SDZ) has been frequently detected in surface waters in recent years. We evaluated the kinetics, mechanisms, intermediate products and bacterial community structure that result from the reaction of SDZ with free chlorine (HOCl/OCl). We examined this in a pilot-scale water distribution system. Neutral pH had the fastest rate of destruction of SDZ. A second-order reaction constant for the destruction of SDZ by chlorine increased with increasing concentration of free chlorine (FC). For different pipe materials, the rate of SDZ degradation decreased as follows: stainless steel (SS) pipe > polyethylene (PE) pipe > ductile iron (DI) pipe. Based on the less complex bacterial diversity and more chlorine-resistant by 16S ribosomal ribonucleic acid (rRNA) gene analysis, SS pipe and PE pipe were more suitable in SDZ degradation in water distribution system (WDS) than DI pipe. In addition, the transformation products from SDZ chlorination were identified by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, and the products included SO extrusion products, haloacetic acids and trihalomethanes. Toxicity tests further confirmed that the toxicity of SDZ chlorination was higher both in low FC (0.7 mg/L) and high FC (1.3 mg/L) in WDS.
磺胺嘧啶（SDZ）近年来在地表水中频繁被检出。本研究评估了磺胺嘧啶（SDZ）与游离氯（HOCl/OCl）反应产生的动力学、机制、中间产物和细菌群落结构。我们在一个中试规模的供水管网系统中对此进行了研究。中性 pH 条件下，SDZ 的破坏速率最快。SDZ 被氯破坏的二级反应常数随游离氯（FC）浓度的增加而增加。对于不同的管道材料，SDZ 降解的速率依次降低：不锈钢（SS）管 > 聚乙烯（PE）管 > 球墨铸铁（DI）管。基于更简单的细菌多样性和 16S 核糖体核糖核酸（rRNA）基因分析的更高的耐氯性，SS 管和 PE 管比 DI 管更适合在供水管网（WDS）中降解 SDZ。此外，通过气相色谱-质谱和液相色谱-质谱鉴定了 SDZ 氯化的转化产物，包括 SO 挤出产物、卤乙酸和三卤甲烷。毒性试验进一步证实，在 WDS 中低 FC（0.7 mg/L）和高 FC（1.3 mg/L）条件下，SDZ 氯化的毒性更高。
