UV-catalytic treatment of spent caustic from ethene plant with hydrogen peroxide and ozone oxidation

Article type: Research Article

Authors: YU, Zheng-zhe^; | SUN, De-zhi | LI, Chang-hai | SHI, Peng-fei | DUAN, Xiao-dong | SUN, Guo-rong | LIU, Jun-xin

Affiliations: Research Center for Ecg-Environmental Sciences, CAS, Beijing 100085, China | Department of Environmental Science and Engineering, Harbin Institute of Technology, Harbin 150001, China

Note: [] Corresponding author. E-mail: [email protected]

Abstract: The performance of UV/H_2O_2, UV/O_3 and UV/H_2O_2/O_3 oxidation systems for treating spent caustic from an ethylene plant was investigated. In UV/H_2O_2 system, with the increase of H_2O_2 dosage, removal efficiencies of COD and the ratio of biochemical oxygen demand (BOD) to chemical oxygen demand (COD) of the effluent were increased and a better performance was obtained than the H_2O_2 system alone. In UV/H_2O_2 system, removal efficiency of COD reach 68% under the optimum condition, and BOD/COD ratio was significantly increased from 0.22 to 0.52. In UV/O_3 system, with the increase of O_3 dosage, removal efficiency of COD and BOD/COD ratio were increased, and a better performance was obtained than the O_3 system alone. Under the optimum condition, removal efficiency of COD was 54%, and BOD/COD ratio was significantly increased from 0.22 to 0.48. In UV/H_2O_2/O_3 system, COD removal efficiency was found to be 22.0% higher than UV/O_3 system.

Keywords: spent caustic, photochemical oxidation, UV/O[TeX:] _3 system, UV/H[TeX:] _2O[TeX:] _2 system, UV/H[TeX:] _2O[TeX:] _2/O[TeX:] _3 system

Journal: Journal of Environmental Sciences, vol. 16, no. 2, pp. 272-275, 2004