Synthesis of a novel magnetic multi-amine decorated resin for the adsorption of tetracycline and copper

Abstract A magnetic multi-amine decorated resin (MmAR-G) was prepared via polymerization, post-crosslinking, and amination reactions for adsorption and coadsorption of tetracycline (TC) and copper (Cu). The results showed that MmAR-G had relatively higher specific surface area, larger pore size, and abundant chelating groups (amino, carbonyl, and hydroxyl groups). Compare with other multi-amine resins, MmAR-G showed maximum uptake for both TC (0.104 mmol/g) and Cu2+ (0.385 mmol/g). The higher specific surface area and protonated amine led to higher TC adsorption capacity. The extra hydroxyl introduced by epoxide-opening reaction when amination, carboxyl, neutral and protonated amines can chelate with Cu2+ and enhance the adsorption, which was demonstrated by the XPS characterization. In the presence of NaCl, the competing adsorption of Cl−decreased the TC adsorption remarkably, and the restrain of the hydrogen bond formation provided more chelation groups and facilitated Cu2+ removal. In binary solutes systems, the formation of Cu-TC complexes decreased TC and Cu2+ adsorption onto MmAR-G by reducing the affinity. Still, the cumulative adsorption amount for TC and Cu2+ onto MmAR-G was highest (0.376 mmol/g). The results showed that MmAR-G was a promising adsorbent for remove and coremove organics and heavy metals in wastewater.