OICC Press International Journal of Industrial Chemistry 2228-5547 17 1 2026 03 31 A Super-Adsorbent Bis-Sulfonated Polyamide for Efficient Cobalt and Chromium Removal 10.57647/ijic.2026.1701.02 EN Marzieh Iravani Department of Chemistry, Shah.C., Islamic Azad University, Shahreza, Iran Maryam Tayebani Department of Chemistry, Shah.C., Islamic Azad University, Shahreza, Iran Journal Article 2026 03 31 Two aromatic polyamides containing sulfone and teraphthalaldehyde moieties were synthesized via the polycondensation reaction of bis-sulfonamide imine and bis-diaminodiphenylsulfone imine monomers with a diacyl chloride. The chemical structures and physicochemical properties of the synthesized polymers were comprehensively characterized by CHN analysis, 1HNMR, FT-IR, UV–Vis spectroscopy, thermogravimetric/differential thermal analysis (TG/DTA), and scanning electron microscopy (SEM). The adsorption performance of the prepared polyamides toward Co²⁺ and Cr³⁺ ions in aqueous media was systematically investigated. The influence of key operational parameters, including pH, temperature, initial metal-ion concentration, and contact time, was evaluated to optimize adsorption efficiency. Under optimal conditions, the polymers exhibited remarkable removal efficiencies of 95.2% for Co²⁺ and 99% for Cr³⁺. Metal ion concentrations before and after adsorption were quantified using atomic absorption spectrometry (AAS). Equilibrium data were analyzed using the Langmuir and Freundlich isotherm models, whereas adsorption kinetics were interpreted using pseudo-first-order and pseudo-second-order models to elucidate the mechanism governing metal-ion uptake.