Thioglycolic acid-modified polysilicate aluminum titanium for high-efficiency Cu2+ removal

Novel Ti-doped thiol-functionalized adsorbent enables efficient Cu 2+ removal. • The adsorption mechanism was verified as sulfur-metal bonding. • PSAT-TGA outperforms conventional non-Ti flocculants in removal efficiency. • Optimal performance achieved at pH 5 with minimal dosage and short settling time. This study presents a novel thiol-functionalized titanium-doped polysilicate aluminum flocculant (PSAT-TGA) designed to address the low adsorption capacity and poor selectivity of conventional flocculants for heavy metal removal. Ti doping was employed to enhance structural stability and surface charge properties, while TGA modification was introduced to provide specific thiol chelating sites for Cu 2+ . The material was characterized by FTIR, XRD, SEM, EDS, XPS, and TEM, and its adsorption performance was evaluated using kinetics, isotherms, parametric optimization, and anti-interference tests. Results showed that PSAT-TGA achieved rapid adsorption equilibrium within 20 min, with a maximum Langmuir adsorption capacity of 391.30 mg/g. The optimal conditions were determined to be pH 5, a dosage of 58.5 mg/L, and a sedimentation time 40 min. The optimal Ti doping ratio was n(Al):n(Ti) = 8:2, and a clear synergistic effect between Ti doping and TGA modification was observed. PSAT-TGA maintained high removal efficiency (>97%) under coexisting ion interference and outperformed several similar flocculants. This work provides a feasible, efficient, and low-cost strategy for designing functionalized silicate flocculants, which shows great practical significance for the treatment of copper-containing wastewater in mining, electronics, and metallurgical industries, and offers a reliable technical solution for solving heavy metal pollution in aquatic environments and safeguarding global water security. Download: Download high-res image (201KB) Download: Download full-size image