Application of smart hydrogels in sustainable treatment of effluents from the textile industry: A review

Abstract

Dyes are among the most harmful contaminants produced by industries such as textile, rubber, paper, and others. These contaminants are eliminated from the production process and disposed of as effluents, most of which are ultimately discharged into bodies of water such as lakes, rivers, beaches, and streams. The majority of these industrial dyes are categorized as toxic and/or carcinogenic, with their stability and ability to integrate into the ecological chain potentially affecting flora and fauna. Additionally, sustainable development goals have been proposed globally since 2015, including the implementation of eco-friendly technologies for the treatment of water resources to enable reuse. Therefore, pretreatment of these textile industrial effluents before their discharge into water bodies is imperative. This paper presents a literature review on effluent treatment using hydrogels, focusing on the textile industry. Hydrogels can serve as an adsorption technology with significant comparative advantages over other removal methods, including low cost, reusability, biodegradability, non-toxicity, absence of secondary pollutants, and ease of operational management. The compiled results underscore the capability of hydrogels in dye removal. Furthermore, their removal efficiency, kinetics, reusability cycles, thermodynamics, equilibrium, and responses to various environmental stimuli reinforce the feasibility of implementing hydrogels as an adsorption technology for treating textile industrial effluents.