Enhanced removal of methylene blue from water using mercaptosuccinic acid-functionalized PS-DVB-g-PGMA polymer

In this study, a polystyrene-divinylbenzene-vinylbenzyl chloride (PS-DVB-VBC) polymer sorbent was synthesized and functionalized with glycidyl methacrylate (GMA) via surface-initiated polymerization, achieving an epoxy group content of 64 %. The epoxy-functionalized polymer was further modified by reacting with mercaptosuccinic acid to enhance its adsorption performance for methylene blue (MB) removal from aqueous solutions. Characterization results confirmed the successful synthesis and functionalization of the sorbent, revealing a mesoporous structure with an average pore diameter of 4.8 nm and a BET surface area of 0.9144 m² g⁻¹. Sorption experiments were conducted under varying conditions, including pH (2−12), initial MB concentrations (1–20 mg L⁻¹), sorbent dosages (10–50 mg), contact times (1–240 min), and temperatures (298–338 K). Kinetic analysis showed that the pseudo-second-order model (R² = 0.9997) best described the adsorption process, while equilibrium data aligned well with the Langmuir isotherm (R² = 0.9996), indicating monolayer adsorption with a maximum capacity of 6.27 mg g⁻¹. Thermodynamic studies confirmed a spontaneous and exothermic (ΔH° = −2.64 kJ mol⁻¹) adsorption process. The polymer sorbent demonstrated excellent adsorption performance in ultrapure water (UPW) and tap water (TW), achieving over 95 % removal efficiency, while maintaining significant MB removal in industrial wastewaters (IWWs), despite the presence of competing contaminants. These results highlight the potential of the developed sorbent for practical wastewater treatment applications.