A comprehensive review on synthesis, characterization and adsorption behavior of agricultural waste based adsorbents for heavy metals (Cr(VI) and Cd(II)) removal from wastewater

Abstract

Water pollution is a significant global issue among various environmental issues on the earth for the sustainability of life. It has drawn considerable attention from researchers due to the continuously increasing discharge of highly toxic pollutants, such as chromium(VI), lead(II), cadmium(II) etc. These toxic ions are primarily released in the water bodies from various effluents generated due to various chemical processes in the industries. Therefore, significant investments from different countries have been made for the emergent research toward the remediation of toxic ions from polluted water. In this review article, a summary of synthesis and comprehensive analysis of a recently reported wide range of lignocellulose-based adsorbents for removing chromium(VI) and cadmium(II) have been complied. This review also summarizes the research data in terms of various physicochemical parameters such as adsorption capacity, specificity and selective affinity. The manuscript outlines the optimized adsorption conditions, reaction mechanism, and different characterization techniques to analyze the adsorbent surface functionality, morphologyand thermodynamic parametershave also been summarized. The current and future efforts toward effectively developing agro-waste-based adsorbents for enhanced purification of contaminated water have also been included.