Study on the treatment of 2-sec-butyl-4,6-dinitrophenol (DNBP) wastewater by ClO2 in the presence of aluminum oxide as catalyst

The chlorine dioxide (ClO2) oxidative degradation of 2-sec-butyl-4,6-dinitrophenol (DNBP) in aqueous solution was studied in detail using Al2O3 as a heterogeneous catalyst. The operating parameters such as the ClO2 concentration, catalyst dosage, initial DNBP concentration, reaction time and pH were evaluated. Compared with the conventional ClO2 oxidation process without the catalyst, the ClO2 catalytic oxidation system could significantly enhance the degradation efficiency. Under the optimal condition (DNBP concentration 39 mg L−1, ClO2 concentration 0.355 g L−1, reaction time 60 min, catalyst dosage 10.7 g L−1 and pH 4.66), degradation efficiency approached 99.1%. The catalyst was used at least 8 cycles without any appreciable loss of activity. The kinetic studies revealed that the ClO2 catalytic oxidation degradation of DNBP followed pseudo-first-order kinetics with respect to DNBP concentration. The ClO2 catalytic oxidation process was found to be very effective in the decolorization and CODCr reduction of real wastewater from DNBP manufacturing. Thus, this study showed potential application of ClO2 catalytic oxidation process in degradation of organic contaminants and industrial effluents.