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Enhanced oxidation of toxic effluents using simultaneous ozonation and activated carbon treatment
Author(s) -
Zaror Claudio A.
Publication year - 1997
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/(sici)1097-4660(199709)70:1<21::aid-jctb706>3.0.co;2-3
Subject(s) - ozone , chemistry , activated carbon , adsorption , reaction rate constant , effluent , decomposition , absorption (acoustics) , carbon fibers , inorganic chemistry , environmental chemistry , kinetics , organic chemistry , waste management , materials science , engineering , physics , quantum mechanics , composite number , composite material
Chemical oxidation and adsorption are feasible options to treat toxic effluents; however, the lack of empirical design data impairs their implementation at industrial scale. This paper reports experimental results on a detoxification system based on enhanced oxidation using ozone in the presence of activated carbon. The study focuses on four representative model toxic phenolic compounds, i.e. 3‐chlorophenol, 4‐chlorophenol, 2‐methoxyphenol, and pyrocatachol. The experimental system consisted of a 1·5 dm 3 stirred reactor and an ozonizer with a mean production capacity of 0·1 mmol O 3 s −1 from pure oxygen. Adsorption and absorption processes were studied in the absence and presence of chemical reactions at pH 2, within the temperature range 15–35°C and solid/liquid ratio 0·05–0·005 w/w. Results showed that all these contaminants are readily oxidized by ozone, with a pseudo‐second order rate constant in the range 0·02–0·08 mmol −1 dm 3 s −1 at pH 2 and temperature 15–35°C. Fast phenolic oxidation reactions at the gas–liquid interphase increased the ozone absorption rate by a factor of 3–10, as compared with physical absorption only. The presence of activated carbon during ozonation significantly improved ozone selectivity. Adsorption isotherms and ozone self‐decomposition data are also reported. ©1997 SCI