Use of a novel coupled-oxidation tubular reactor (COTR)/ NTP-DBD catalytic plasma in a synergistic electro-catalysis system for odorous mercaptans degradation

In this work, a novel coupled-oxidation tubular reactor (COTR)/non-thermal dielectric barrier discharge (NTP-DBD) catalytic plasma in a synergistic electro-catalysis system was investigated for odorous mercaptans decomposition. In order to enhance the degradation efficiency of electro-oxidation, a novel enhanced Ti/PbO 2 electro-catalytic tubular reactor prepared by using flow dynamic electrodeposition was designed and applied as pretreatment process for CH 3 SNa wastewater. The results indicated that the optimal condition was 7 mA cm −2 of current density, 10 g L −1 of initial concentration of CH 3 SNa, 9.0 of pH and 5.0 g L −1 of electrolyte concentration. Addition of Fe 2+ and H 2 O 2 and mechanism of COTR system were first put forward. The target species CH 3 SNa were removed over 90% by this process. In order to treat the CH 3 SH effusion which was co-produced with CH 3 SNa aqueous solution, the technology of NTP-DBD catalytic plasma reactor followed by a chemical absorption has been developed. MSH could be removed over 95% under the condition of 2 s of residence time, 15 kV of output voltage with oxygen concentration of 9%. Moreover, the synthetic Ni-doped AC catalyst had the best performance under 0.7 mmol g −1 of nickel loading. The conclusion was the energetic electrons generated in the DBD reactor played a key role on the removal of MSH, and the major decomposition products of MSH were detected as CH 3 SSCH 3 , SO 2 and NO 2 . Moreover, the gaseous products in the plasma exhaust could be absorbed and fixed by the subsequent aqueous NaOH solution.