科研之友
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摘要
Photoactivation of SO32- with UV (254 nm) irradiation was adopted to generate the hydrated electron-based advanced reduction process, which was used to degrade BrO3- in water. The second-order reaction rate constant of BrO3- with hydrated electron was determined, and the effects of operational parameters (dosage of SO32-,solution pH, HCO3-, humic acids (HA), and dissolved oxygen (DO)) were evaluated. The transformation intermediates of BrO3- and SO32- were identified and mass balances of bromine and sulfur were checked. Results showed a positive correlation between the removal efficiency of BrO3- and dosage of SO32- (0.5-2.0 mM). Increasing the solution pH from 5 to 9 promoted elimination of BrO3- because of the pH-dependent effect of SO32- photoactivity, whereas further increasing the pH from 9 to 10 caused no further enhancement. In addition, 1-4 mM HCO3- exerted about 5% inhibition on BrO3- destruction, indicating that HCO3- is a weak inhibitor. The presence of 1.5-4.0 mg L-1 HA deteriorated BrO3 degradation, while depletion of DO by N-2 bubbling benefitted BrO3- removal. The balances of bromine and sulfur denoted that the final transformation products of BrO3- and SO32- were harmless SO32-, bromide, and minor dithionate.
- 出版日期2014-10
- 单位浙江大学
