Urea adsorption from aqueous solutions by Cu(II)- water-based membrane: kinetics and thermodynamics

Urea is well known as a significant environmental pollutant widely used in agricultural, industrial, and biomedical sectors. However, although numerous methods have been developed for urea removal, many of which have limitations such as high cost, low efficiency, or technological immaturity. In this study, a new copper additive water-based polymeric membrane was synthesized, and its performance urea adsorption from aqueous solutions was evaluated. The adsorption data obtained were analyzed using different isotherm models, and the adsorption behavior of the system was comprehensively analyzed. According to the error analysis, the order of fit was Dubinin-Radushkevich > Temkin > Sips. The kinetic and thermodynamic parameters of the adsorption process were systematically researched. From the experimental results, it was determined that the urea adsorption followed the pseudo-first order kinetic model. From the thermodynamic analysis, it was specified that the adsorption was spontaneous and exothermic, with negative ΔG° and ΔH° values. An impressive urea adsorption capacity (qₘ) of 191.90505 ± 7.95582 mg/g was achieved with the Cu (II) additive membrane, indicating electrostatic interactions and chelation mechanisms. The E value obtained from the Dubinin-Radushkevich (DR) isotherm model shows that the process is characterized by physical adsorption. This study has developed an innovative membrane material that combines cost-effectiveness, environmental sustainability, and potential applicability in biomedical fields, especially for toxic urea adsorption. These findings demonstrate the strong potential of copper-enhanced membranes for next-generation wastewater treatment and blood purification technologies.