Different Role of Bisulfite/Sulfite in UVC-S(IV)-O<sub>2</sub> System for Arsenite Oxidation in Water
Tao Luo,
Zhenhua Wang,
Yi Wang,
Zizheng Liu,
Ivan P. Pozdnyakov
Affiliations
Tao Luo
Department of Environmental Science and Engineering, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
Zhenhua Wang
Department of Environmental Science and Engineering, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
Yi Wang
School of Civil Engineering, Engineering Research Center of Urban Disasters Prevention and Fire Rescue Technology of Hubei Province, Wuhan University, Wuhan 430072, China
Zizheng Liu
School of Civil Engineering, Engineering Research Center of Urban Disasters Prevention and Fire Rescue Technology of Hubei Province, Wuhan University, Wuhan 430072, China
Ivan P. Pozdnyakov
Voevodsky Institute of Chemical Kinetics and Combustion, Institutskaya 3, 630090 Novosibirsk, Russia
It is of interest to use UV-sulfite based processes to degrade pollutants in wastewater treatment process. In this work, arsenic (As(III)) has been selected as a target pollutant to verify the efficacy of such a hypothesized process. The results showed that As(III) was quickly oxidized by a UV-sulfite system at neutral or alkaline pH and especially at pH 9.5, which can be mainly attributed to the generated oxysulfur radicals. In laser flash photolysis (LFP) experiments (λex = 266 nm), the signals of SO3•− and eaq− generated by photolysis of sulfite at 266 nm were discerned. Quantum yields for photoionization of HSO3− (0.01) and SO32− (0.06) were also measured. It has been established that eaq− does not react with SO32−, but reacts with HSO3− with a rate constant 8 × 107 M−1s−1.
