Process and kinetics of dye degradation using microplasma and its feasibility in textile effluent detoxification

Abstract

An array of microplasma discharge was formed on a static aqueous surface by using a high voltage AC power source. The production of hydroxyl radicals (OH) and hydrogen peroxide (H2O2) during the plasma-water-air interaction were quantified and studied their role in the degradation of textile dye i.e. Remazol blue RGB (RB RGB) and as-received textile effluent. Degradation efficiency was evaluated at different applied voltages and initial concentration of dye. The results showed that the microplasma discharge exhibited 99.4 % of degradation efficiency for 50 ppm of RB RGB within 16 min of treatment time and 22.4 % mineralization was achieved. The degradation efficiency increased on increasing the applied input voltage, while it decreased on increasing the initial concentration of dye. Further, the actual textile effluent (received from Tiruppur district, Tamilnadu, India) was treated with this microplasma discharge array and the formation of energetic electrons and free radicals during treatment significantly mineralized the as-received textile effluent with considerable reduction of total organic carbon i.e. 88.6 %. Phytotoxicity studies results reveal that the toxicity of textile effluent was significantly reduced by using the microplasma array discharge.