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Effect of recycling overhead gases on pollutants degradation efficiency in gas-phase pulsed corona discharge treatment
Date Issued
01-02-2018
Author(s)
Pothanamkandathil, Vineeth
Singh, Raj Kamal
Indian Institute of Technology, Madras
Ramanujam, Sarathi
Abstract
In the present study, pollutant degradation efficiency was investigated by recycling of overhead gases from gaseous phase to aqueous phase in gas-liquid interface pulsed corona discharge reactor. Methylene blue (MB) was used as a model pollutant and its degradation was compared by recycling and non-recycling of oxygen, air and argon gases. The degradation rate constants of MB were 0.28 and 0.23 min−1 in recycled condition which was decreased to 0.22 and 0.21 min−1 in non-recycled condition in oxygen and argon gas, respectively. On contrary, in air medium, comparatively higher MB degradation rate (0.21 min−1) was achieved in non-recycled condition compared to recycled condition (0.11 min−1). The long-lived reactive oxygen species (ROS) such as hydrogen peroxide and ozone were quantified in both conditions. We observed that the concentration of ozone present in the aqueous solution was slightly higher in recycling conditions as compared to that of non-recycled condition in all the gases. Moreover, higher hydrogen peroxide concentration was detected in recycled condition (185 and 168 mg/L) compared to non-recycled condition (112 and 40 mg/L) in the presence of oxygen and argon, respectively, and vice-versa in air medium. The economic comparison revealed that up to 33% of electrical energy could be saved by recycling overhead oxygen gas.
Volume
6