Multi-Recyclable Eco-Friendly Chitosan Beads: An Efficient Adsorbent for Removal of Crystal Violet Dye

Abstract

Crystal Violet (CV) enters in water bodies through the effluents of textile, medical, paint, biotechnology industries. CV considered as mutagenic and mitotic in nature and also causes skin irritation, eye damage and other severe effects on human as well as aquatic lives. Due to its toxicity and harmful effects, environmental agencies have put strict regulations on discharge of CV dye contaminated water into natural water bodies. In the past decades, several processes have been cited in the literature for the decontamination of CV dye; however they have their own limitations for purification. Most of the cited processes require sophisticated tools to separate adsorbent from water after purification. For the proposed adsorbent, there is no need of such filtration processes as the proposed chitosan beads can be easily removed from water after purification without any tools. The same beads can be utilized several times just simple chemical reactivation. In the proposed process, we have utilized the same beads up to eight times and the removal efficiency was found to be more than 90% within 90 minutes. The material is cost effective, eco-friendly and easy to synthesize. To understand the adsorption rate and the adsorption mechanism of CV over chitosan beads, the kinetics and adsorption isotherms models were analyzed. The obtained experimental adsorption data was found to be best fitted to pseudo second order kinetics and Langmuir adsorption isotherm.