Comparative study on the adsorption of lead ions by kaolin loaded chitosan by different modification methods

Abstract

The adsorption effect of two modified kaolin-chitosan composites prepared by different modification methods (cross-linking method (GL-CS) and click reaction method (TGL-CS)) on lead ion wastewater was studied. The structure of TGL-CS has a denser pore structure than that of GL-CS, and the distribution of adsorption sites is more uniform. At 25 °C, pH 4, the adsorbent dosage of 0.05 g/dm3, reaction time of 4 h, and initial mass concentration of 150 mg/dm3, TGL-CS had the best effect on Pb2+ wastewater treatment, and the adsorption capacity was 76.159 mg/g. The adsorption studies of kinetic, thermodynamic, and ther-modynamic parameters showed that the adsorption on GL-CS and TGL-CS was best described by the Langmuir model. The adsorption mechanism is mainly chemical adsorption. The adsorption process is spontaneous. These results show that the adsorbent prepared by click reaction has obvious advantages, with more adsorption capacity and adsorption sites, faster adsorption rate, and better application potential.