Eco-friendly adsorbents for industrial dye removal: A comprehensive review of low-cost alternatives

Abstract

This review examines the removal of industrial dyes using cost-effective natural adsorbents, emphasizing their role as an alternative to expensive activated carbon. Dyes are extensively used in industries such as textiles, rubber, plastics, printing, leather, and cosmetics, leading to the discharge of significant volumes of colored wastewater. These dyes pose serious environmental and health risks due to their carcinogenic, mutagenic, and toxic properties. Various treatment methods are available for dye removal, with adsorption being one of the most effective approaches. The increasing need for efficient and affordable wastewater treatment solutions has driven interest in low-cost alternative adsorbents (LCAs). This review provides a comprehensive overview of LCAs, including naturally occurring materials, industrial byproducts, and synthetic wastes, highlighting their potential for dye removal. The mechanisms and effectiveness of these adsorbents are discussed in detail, along with key factors influencing their adsorption performance. A thorough literature survey reveals that certain LCAs not only offer widespread availability but also exhibit rapid adsorption kinetics and significant adsorption capacities. The advantages and limitations of different adsorbents, optimal conditions for specific adsorbate-adsorbent interactions, and comparative adsorption capacities of various LCAs and commercial activated carbon are analyzed based on existing studies. Finally, conclusions are drawn from the literature analysis, summarizing key findings and understandings of the potential of life cycle assessments (LCAs) for sustainable wastewater treatment. With an emphasis on particularly beneficial materials like chitosan, agricultural biomass, and clay-based adsorbents due to their availability, renewability, and remarkable adsorption efficacy, this review provides forward-looking perspectives and recommendations regarding the development of LCAs for cost-effective water treatment. • The review explores the removal of industrial dyes from wastewater using cost-effective natural adsorbents as sustainable alternatives to activated carbon. • Industrial dyes pose severe environmental and health risks due to their carcinogenic, mutagenic, and toxic nature. Identifying efficient and affordable treatment methods is crucial for sustainable wastewater management. • Low-cost alternative adsorbents (LCAs) derived from natural materials, industrial byproducts, and synthetic wastes exhibit significant adsorption capacities, such as wide availability, eco-friendly, cost-effectiveness, and high adsorption efficiency under optimized conditions. • The review presents a detailed evaluation of adsorption mechanisms, key influencing factors, and comparative performance analysis of various adsorbents.