Degradation of carbamazepine by vacuum-UV oxidation process: Kinetics modeling and energy efficiency

Shumin Zhu; Bingzhi Dong; Yangtao Wu; Lingjun Bu; Shiqing Zhou

doi:10.1016/j.jhazmat.2019.01.043

Degradation of carbamazepine by vacuum-UV oxidation process: Kinetics modeling and energy efficiency

J Hazard Mater. 2019 Apr 15:368:178-185. doi: 10.1016/j.jhazmat.2019.01.043. Epub 2019 Jan 15.

Authors

Shumin Zhu¹, Bingzhi Dong², Yangtao Wu³, Lingjun Bu⁴, Shiqing Zhou³

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, United States.
² State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. Electronic address: dbzwater@163.com.
³ Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, Hunan, 410082, China.
⁴ Department of Water Engineering and Science, College of Civil Engineering, Hunan University, Changsha, Hunan, 410082, China; Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, OH, 45221-0012, United States.

PMID: 30677649
DOI: 10.1016/j.jhazmat.2019.01.043

Abstract

Vaccum-ultraviolet (VUV) is effective for elimination of organic contaminants in aqueous environment and degradation of carbamazepine (CBZ) by VUV irradiation was systematically investigated in this study. A dynamic kinetic model was developed to simulate the destruction of CBZ that is mainly initiated by hydroxyl radicals (HO). The second-order rate constant of the reaction between CBZ and HO was determined to be 1.4 × 10⁹ M^-1 s^-1. Effect of initial CBZ concentration, VUV irradiation intensity and natural organic matter (NOM) were further investigated in several batch experiments. The predicted CBZ removal rates increased with the increasing VUV intensity, while decreased with the increasing initial CBZ and NOM concentrations. Based on the electrical energy per order (EE/O) calculation, the optimal VUV intensity was determined to be 7.5 × 10^-8 Einstein s^-1. Meanwhile, several intermediates/products were identified and their time-dependent evolution profiles were determined, and finally a plausible degradation pathway of CBZ was proposed. Ecotoxicity assessment indicated that the potential toxicity of CBZ and its oxidation products should be paid more attention in the VUV process.

Keywords: Degradation pathway; Energy efficiency; Hydroxyl radical; Kinetic model.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carbamazepine / analysis*
Carbamazepine / radiation effects
Electric Power Supplies* / supply & distribution
Hydroxyl Radical / chemistry
Kinetics
Oxidation-Reduction
Ultraviolet Rays*
Vacuum*
Water Pollutants, Chemical / analysis*
Water Pollutants, Chemical / radiation effects
Water Purification / methods*

Substances

Water Pollutants, Chemical
Hydroxyl Radical
Carbamazepine