Proximative and Contrastive Study of Malachite Green Dye Degradation Using Microplasma Discharge With Postliminary Phytotoxicity Analysis

Abstract

Array of microplasma jets has been produced in atmospheric conditions using a high-voltage ac power source for the degradation of malachite green (MG) dye in the aqueous solution. The effect of plasma forming gases (air, oxygen, and argon) on the degradation was analyzed by UV-Vis spectrophotometer, and the formation of hydrogen peroxide during plasma–water interaction was quantified. Oxygen plasma produced a relatively high amount of hydrogen peroxide than air and argon, leading to efficient degradation. Oxygen plasma medium exhibited 14.78% and 9.85% higher energy yield than air and argon plasma, respectively. Observation shows that the degradation of MG dye in the aqueous solution follows the first-order kinetics irrespective of plasma forming gases. Phytotoxicity of untreated and oxygen microplasma treated MG dye solution was examined with the germination of tomato seeds. The results illustrate that the toxicity of MG dye was considerably reduced with the microplasma discharge treatment, as it induced 17.4% higher germination percentage than control. The study delineates that oxygen microplasma is an effective, economic and eco-friendly tool for detoxification of huge amount of MG dye in the aqueous medium.