Introducing a new co-polymeric adsorbent with fast sorption rate and high sorption capacity for removing the heavy metal ions: A thermodynamic and kinetic study

Heavy metal ions received special attention as the most hazardous contaminants of water sources. In this study, a novel polymeric adsorbent based on 2-hydroxyethyl methacrylate (HEMA), Acrylic Acid (AA), and 1,4-butanediol dimethacrylate (BDDMA) was successfully synthesized and its efficiency for removing the selected heavy metal ions (Pb2+ and Cd2+) was investigated. The role of significant parameters such as pH, contact time, adsorbent dose, metal ions concentration, and temperature in removing harmful metal ions were logically studied. The results of the present study showed that there is a direct relation between the parameters such as the amount of pH, the contact time, the polymer adsorbent dosage, and the adsorption of metal ions. This is while the increase of the metal ion concentrations had no significant effect on the adsorption of metal ions which were fixed up to 15 mg/L. The adsorption isotherm process for the new polymeric adsorbent was studied by using selected models, also the maximum values of the adsorption capacities of the introduced adsorbent for Pb2+ and Cd2+ ions were determined. The adsorption /desorption cycles of synthesized polymer adsorbent were repeated 15 times. By modeling the adsorption data, the pseudo-second-order kinetic equation could best describe the adsorption kinetics. The results of the intra-particle diffusion studies showed that the adsorption of heavy metal ions might fallow the external diffusion mechanism. (C) 2021 Sharif University of Technology. All rights reserved.

Automated summary

A novel polymeric adsorbent for removing heavy metal ions was successfully synthesized and its efficiency was investigated in this study. The study found direct relations between parameters such as pH, contact time, adsorbent dose, and the adsorption of metal ions. In addition, the adsorption isotherm process and kinetics suggest that heavy metal ions adsorption might follow the external diffusion mechanism.