Degradation of sulfonamides and formation of trihalomethanes by chlorination after pre-oxidation with Fe(VI)

Tuqiao Zhang; Feilong Dong; Feng Luo; Cong Li

doi:10.1016/j.jes.2018.01.016

Degradation of sulfonamides and formation of trihalomethanes by chlorination after pre-oxidation with Fe(VI)

J Environ Sci (China). 2018 Nov:73:89-95. doi: 10.1016/j.jes.2018.01.016. Epub 2018 Feb 2.

Authors

Tuqiao Zhang¹, Feilong Dong², Feng Luo², Cong Li³

Affiliations

¹ College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China. Electronic address: ztq@zju.edu.cn.
² College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China.
³ College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027, China. Electronic address: congil@zju.edu.cn.

PMID: 30290875
DOI: 10.1016/j.jes.2018.01.016

Abstract

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) (Fe^VIO₄^2-, 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.

Keywords: Ferrate(VI); Free chlorine; Sulfadiazine; Sulfamethazine; Trihalomethanes.

MeSH terms

Halogenation
Iron / chemistry*
Sulfonamides / chemistry*
Trihalomethanes / chemistry*
Water Pollutants, Chemical / chemistry*
Water Purification / methods*

Substances

Sulfonamides
Trihalomethanes
Water Pollutants, Chemical
ferrate ion
Iron