Competitive and synergistic effects of metal adsorption in water remediation processes mediated by hybrid copolymers

Abstract

Copolymers based on vegetable oils and sulfur have recently been developed using the inverse vulcanization technique for water remediation. This study aimed to create a copolymer with heteroatoms, such as nitrogen, to improve adsorption efficiency and examine the competition and synergy between heavy metals in the adsorption process. FTIR, 1H NMR, solid 13C NMR, zeta potential, nitrogen adsorption, Elemental analysis, TEM, and SEM were used to characterize the copolymers synthesized. Once metal adsorption was optimized using the synthesized copolymers, a comparative adsorption study was conducted for the removal of individual heavy metals, Cd2+, Pb2+, Zn2+, Mn2+, and Cu2+ (100 mg/L), using two copolymers, S/CO:80/20 and S/CO/TAA:80/14/6. The copolymers exhibited a higher affinity for soft metals, such as Cd2+, Pb2+, and Cu2+, when they are individually and in a mixture. After 1 h, the S/CO:80/20 copolymer removed 47%, 40%, and 13% of these metals. While with the S/CO/TAA:80/14/6 copolymer removal increased to 10%, 24%, and 53%, respectively respect to S/CO:80/20 copolymer. The introduction of heteroatoms in the copolymers improved their removal efficiency, particularly for heavy metals like Pb2+. Overall, this study demonstrates a promising approach for sustainable water remediation using copolymers.