Synthesis of activated carbon using pyrolytic degradation of multi plastic waste and its removal efficiency of dye

Abstract

Malachite Green is a persistent pollutant, and it has been reported to cause many harmful health hazards for both humans and aquatic organisms. Growing use of plastic is posing a lot of problems and the most pertinent of which is perhaps the treatment of plastic waste. In the present work, plastic waste has been pyrolyzed, annealed and treated with sodium hydroxide to synthesize a char. Then this char has been used to remove the cationic dye Malachite Green from water and was observed highest removal of Malachite Green by the char was 99.3 %. From the thermodynamic study, it was observed that the value of Gibbs free energy was negative across all the temperature thereby denoting that the process was spontaneous. The process was optimized with an Artificial Neural Network system and from there it was observed that the Levenberg-Marquardt backpropagation model best optimized the experimental data. The char also exhibited high efficiency for the purpose of removing other cationic dyes and polyaromatic hydrocarbons, whereas showing a lower affinity for anionic dyes and pharmaceutical compounds.