Study on Adsorption of Functional Nitrogen Heterocyclic Carbene Polymeric Resin for Cu2+.

The functional nitrogen heterocyclic carbene polymeric resin (PNO) was synthesized for the removal of Cu²⁺ from wastewater. Based on static and dynamic adsorption experiments, the adsorption effect of PNO on Cu²⁺ in wastewater was studied. The results showed that the optimal adsorption conditions of PNO for Cu²⁺ were as 100 mg of adsorbent dosage, 30 minutes of adsorption time, 4~5.9 of pH, a temperature of 298 K, and a rotational speed of 150 r/min. The maximum adsorption capacity was 51.55 mg/g. The adsorption process was consistent with the Langmuir and Freundlich isothermal adsorption models, as well as the pseudo-second-order kinetic model. The dynamic adsorption capacity increased with the decrease in flow velocity, the increase in column height, and Cu²⁺ concentration. Thomas and Bohart-Adams models' results indicated that the predicted values were consistent with the experimental data (R²>0.92). After 5 rounds of static adsorption and desorption, and 3 cycles of dynamic regeneration, the removal rate still exceeded 96% of the initial cycle, indicating effective removal and regeneration capabilities. This study highlighted that PNO had a wide application prospect for the efficient treatment of copper-containing wastewater. [ABSTRACT FROM AUTHOR]