Environmental Application of Agro-waste Derived Materials for the Treatment of Dye-polluted Water: A Review

Abstract

Background: The extensive industrialization and unrestricted development of dyeutilizing industries coupled with the shortage of proper effluent treatment methods have increased the water pollution. Disposal of dyes in a natural water system is a severe worldwide concern owing to the harmful effects on the ecosystem. Among the available wastewater treatment methods, adsorption is considered as a promising alternative in the elimination of dyes. Methods: There are a variety of ways for the modification of agro-waste, such as (i) acid modification (ii) alkali modification, (iii) surfactant modification, and (iv) preparation of activated carbon, etc. Moreover, numerous techniques have been used for the characterization of modified agro-waste, such as, SEM/EDAX, TEM, BET, TGA, and FTIR. Results: From the literature study, it was observed that the adsorption efficiency of various modified agro-waste is reliant on the nature of the adsorbent materials and different batch parameters, such as initial dye concentration, solution pH, adsorbent dose, and temperature of the system. In this way, these components must be thought about while evaluating the elimination of dye using various agrobased adsorbents. Conclusion: Modification of agricultural waste usually improved the adsorption capacity of adsorbents due to an escalation in the number of active adsorbing sites, enhancement in the porosity, increase in the surface area, and generation of new functional groups that favor the removal of dye from wastewater. Agro-waste materials being inexpensive, abundant, and renewable can be effectively exploited for the confiscation of dye from aqueous media.