College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China.
J Environ Sci (China). 2018 Nov;73:89-95. doi: 10.1016/j.jes.2018.01.016. Epub 2018 Feb 2.
Sulfonamides are used in human therapy, animal husbandry and agriculture but are not easily biodegradable, and are often detected in surface water. Sulfamethazine (SMZ) and sulfadiazine (SDZ) are two widely used sulfonamide antibiotics that are used heavily in agriculture. In this study, they were degraded in an aqueous system by chlorination after pre-oxidation with ferrate(VI) (FeO, Fe(VI)), an environmentally friendly oxidation technique that has been shown to be effective in degrading various organics. The kinetics of the degradation were determined as a function of Fe(VI) (0-1.5mg/L), free chlorine (0-1.8mg/L) and temperature (15-35°C). According to the experimental results, SMZ chlorination followed second-order kinetics with increasing Fe(VI) dosage, and the effect of the initial free chlorine concentration on the reaction kinetics with pre-oxidation by Fe(VI) fitted a pseudo-first order model. The rate constants of SDZ and SMZ chlorination at different temperatures were related to the Arrhenius equation. Fe(VI) could reduce the levels of THMs formed and the toxicity of the sulfonamide degradation systems with Fe(VI) doses of 0.5-1.5mg/L, which provides a reference for ensuring water quality in drinking water systems.
磺胺类药物被广泛应用于人类治疗、畜牧业和农业中，但它们不易生物降解，经常在地表水被检测到。磺胺甲恶唑（SMZ）和磺胺嘧啶（SDZ）是两种广泛使用的磺胺类抗生素，在农业中大量使用。在这项研究中，它们在铁酸盐（VI）（FeO，Fe（VI））预氧化后通过氯化在水溶液中降解，铁酸盐（VI）是一种环保的氧化技术，已被证明可以有效地降解各种有机物。确定了降解动力学作为 Fe（VI）（0-1.5mg/L）、游离氯（0-1.8mg/L）和温度（15-35°C）的函数。根据实验结果，SMZ 的氯化反应符合二阶动力学，随着 Fe（VI）剂量的增加而增加，初始游离氯浓度对 Fe（VI）预氧化反应动力学的影响符合准一级模型。不同温度下 SDZ 和 SMZ 氯化的速率常数与阿仑尼乌斯方程有关。Fe（VI）可以降低 THMs 的形成水平和磺胺类降解系统的毒性，在 0.5-1.5mg/L 的 Fe（VI）剂量下，这为确保饮用水系统的水质提供了参考。
