Low-Cost Agricultural Waste-Derived Adsorbents for Dye Removal from Wastewater: Source, Mechanism and Sustainability Perspectives: A Critical Review

Abstract

The extensive use of synthetic dyes in textile, leather, paper, food, and medicinal industries has given rise to in the release of vastly colored wastewater, posing serious environmental and health anxieties. Conventional dye removal techniques, like chemical oxidation, membrane filtration, and coagulation–flocculation, often suffer from expensive operational, high-energy demand, and generation of secondary product as pollutants cause pollution. Now a day’s, agricultural waste materials have arisen as sustainable, inexpensive, and eco-friendly substitutes for dye removal from contaminated water. These wastes, together with fruit peels, crop residues, husks, shells, and stalks, are rich in cellulose, hemicellulose, lignin, and functional groups that improve their adsorption potential. This review comprehensively discusses the application of agricultural waste derived adsorbents for dye removal, concentrating on their sources, physicochemical properties, adsorption mechanisms and performance toward various grades of dyes. The effects of operational parameters like surface modification are critically analyzed. Also, regeneration potential, economic viability, and ecological sustainability of agricultural waste–based adsorbents are emphasized. The review emphasizes the role of agricultural waste valorization in wastewater treatment and its contribution toward circular economy and sustainable environmental management.