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Indexed by:期刊论文

Date of Publication:2016-05-14

Journal:DESALINATION AND WATER TREATMENT

Included Journals:SCIE

Volume:57

Issue:23

Page Number:10616-10625

ISSN No.:1944-3994

Key Words:Ozonation; Bubble column; Hydroxyl radical; Kinetic process; Degradation

Abstract:Ozonation experiments were conducted in a bubble column reactor taking methylene blue (MB) as model compound, where the role of solution pH and organic load as basic parameters of wastewater influencing pathway of hydroxyl radical (HO center dot) and the kinetics were investigated. The relative significance of HO center dot = pathway was evaluated compared to molecular ozone in both kinetics and degradation process. Results showed that, as solution pH increased from 5 to 11, the contribution of HO center dot (labeled as theta) got intensified from 0.05 up to 0.80 (apparent HO center dot abundance proliferated up to 35.76 x 10(-7) M), giving rise to an exponential growth of pseudo-first-order rate constant as well as an enhanced mineralization. Reduction of initial organic concentration ([C](0,MB)) retarded chemical gas-to-liquid absorption of ozone and the global degradation of MB, while interestingly at the same time, the kinetic rate constant on MB decolorization accordingly began to grow up since the HO(center dot-)pathway impact substantially got reinforced (theta elevated from 0.80 up to 1.944 when [C](0,MB) decreased from 80 to 20 mg L-1 under pH 11).