Abstract
Advanced water treatment technologies must offer selective, efficient, and cost-effective contaminant removal. In this study, TPB-DMTP-COF-SH, prepared from 1,3,5-tris(4-aminophenyl)benzene (TPB) and 2,5-dimethoxyterephaldehyde (DMTP), was synthesized via a two-step method and applied for the adsorption of aluminum (Al(3+)), iron (Fe(2+)), and manganese (Mn(2+)) ions from water. Adsorption performance was influenced by pH, initial concentration, and contact time, with optimal pH values of 3 for Al(3+), 8 for Fe(2+), and 10 for Mn(2+). The adsorption data followed the Langmuir isotherm model, yielding maximum capacities of 3.27 mg g(-1) (Al(3+)), 8.5 mg g(-1) (Fe(2+)), and 0.67 mg g(-1) (Mn(2+)). Kinetic studies indicated a pseudo-second-order mechanism, suggesting chemisorption as the dominant process. Equilibrium adsorption was reached at 15 min for Al(3+) and Mn(2+) and 20 min for Fe(2+). As a proof of concept, we demonstrate that this thiol-functionalized COF not only effectively removes metals but also offers enhanced processability into composite beads and membranes, making it a strong candidate for real-world water treatment applications. These findings highlight TPB-DMTP-COF-SH as a promising and scalable solution for water purification.