Taliored Mechanically Robust Sustainable Hydrogel Adsorbents for Industrial Wastewater Remediation

ABSTRACT Dye wastewater encounters environmental challenges due to its complex composition, which often includes toxic and non‐biodegradable compounds such as dyes. These problems force us to find efficient and sustainable treatment methods. Among existing technologies, the adsorption method was popular for its operational simplicity, low cost, and environmental safety. Hydrogels adsorbents have gained attention due to their tunable 3D networks. These networks can be functionally customized through cross‐linking strategies. In this study, multi‐walled carbon nanotubes (MWCNTs) were exfoliated with ionic liquids (ILs) and inserted into a sodium alginate (SA)‐based hydrogel matrix, named as pAAM/pAA/LMA/SA/ILs‐MWCNTs (PLS) adsorbent. This hydrogel was used to remove cationic (Methylene Blue, MB) and anionic dyes (Methyl Orange, MO). We used pseudo‐first‐order and Langmuir models for kinetics and isotherms, respectively. The adsorption was mainly driven by hydrogen bonding, electrostatic interactions, and π–π stacking. Cyclic adsorption tests showed that PLS had good reusability, and its strong mechanical properties kept it structurally stable over repeated cycles. This sustainably synthesized hydrogel combines mechanical strength with high adsorption performance. It provides an economical, efficient, and durable approach for industrial wastewater treatment.