Chitosan- or glycidyl methacrylate-based adsorbents for the removal of dyes from aqueous solutions: a review

Abstract

Dyes have been found in industrial effluent, highlighting the need for effective treatment. Different processes like filtration, flocculation, and adsorption are low-cost, and efficient methods used for the removal of organic pollutants from wastewater (WW). The utilization of natural and synthetic materials for the above-mentioned processes has recently received a lot of attention. Based on the literature, the most promising sorbents are those derived from chitosan (CS) or glycidyl methacrylate (GMA) due to their various properties: availability, stability, sorption capacity, and durability. This overview presents studies involving the use of CS or GMA as dye adsorbents and their modifications using different functional materials. CS and GMA derivatives have good water-purification properties, and they can be utilized to clean WW effectively. This Review highlights the use of CS or GMA in WW treatment from organic dyes. To understand how CS and GMA may remove organic dyes from WW, thorough knowledge of their adsorption capabilities is required. For example, the adsorption capacity of the carboxymethylated CS-conjugated magnetic nano-adsorbent for Acid Orange 12 dye and GMA-substituted dextran with acrylic acid for methylene blue reached 1883 and 1994 mg g⁻¹, respectively. The Langmuir isotherm model and the pseudo-second-order kinetic model were the most applicable for describing dye adsorption. Furthermore, recent breakthroughs in various CS and GMA composites, as well as diverse ways to remove organic dyes from WW, are discussed in multiple instances to offer a framework for future research. The GMA/CS hybrid material is recommended for future investigations. This could be useful for creating more effective contaminant-removal methods, bridging the gap between laboratory results and industrial applications.