Degradation of Aqueous Organic Pollutants by Catalytic Nonthermal Plasma based Advanced Oxidation Process

Aqueous organic pollutants are a diverse group of chemicals, treated like potential environmental pollutants. Advanced Oxidation Process (AOP), which is based on the generation of highly reactive species, especially hydroxyl radicals has been receiving increasing attention as a possible remediation treatment for their removal. Nonthermal plasma (NTP) dielectric barrier discharge (DBD) reactor was developed as a possible new technology for the degradation and mineralization of aqueous organic compounds from water. The electrical discharges were produced in a parallel plane type coaxial NTP-DBD reactor. The combination of plasma discharge with different catalysts was investigated for the degradation and mineralization of model pollutants like dyes, pesticides, intermediates and pharmaceutical compounds. The effect of various operating parameters, such as initial concentrations, gas feed, applied voltage, catalyst on the performance of the reactor for mineralization was studied. Also, the degradation products were identified to understand the degradation pathways based on which possible mechanisms were proposed. Results indicated that the combination of the metal oxide catalyst with the NTP was found to enhance degradation as well as mineralization. Typical results showed that the pollutant structures were destroyed in plasma reactor, leading to mineralization. The identification by HR-MS analyses indicated that some organic acids could be the degradation products