(381o) Co(II) Recovery from Electronic Waste Based on Ion-Imprinting of Reduced Schiff Base Ligand on Magnetite
Preliminary results from LLE of Co(II) reveal q = 105.3 mg Co(II) g-1 for r-AHB-PDA and 12.2 mg Co(II) g-1 for r-AHB-TAEA. The ligand r-AHB-PDA was chosen for the synthesis of ion-imprinted polymers (IIPs) on a magnetic support material, a practical approach that would minimize reagent use and simplify the Co(II) recovery process. Ion-imprinting technique imparts selectivity towards Co(II) as the r-AHB-PDA binding sites are pre-arranged or templated specifically for the target Co(II). Meanwhile, the magnetic core renders the adsorbent useful for cycled adsorption and desorption of Co(II). For the synthesis of Co(II) selective magnetic-IIP using Schiff base as ligand, magnetite (Fe3O4) was initially prepared by co-precipitation of FeCl3/FeCl2 under basic conditions. Its surface was then coated with silica by tetraethylorthosilicate (Fe3O4@SiO2), then functionalized with alkene by 3-methacryloyloxypropyltrimethoxysilane (Fe3O4@SiO2-MATES) as co-monomers of r-AHB-PDA ligand. Radical polymerization between the Fe3O4@SiO2-MATES and r-AHB-PDA was then carried out using azobisisobutyronitrile (AIBN) as radical initiator and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The adsorbent was thoroughly characterized via FTIR, SEM, XRD, TGA and elemental analysis. Its adsorption properties (i.e. isotherms, kinetics and selectivity) and recyclability are currently being investigated. This work was supported by National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (2017R1D1A1B03028102 and 2017R1A2B2002109) and Ministry of Education (2009-0093816 and 22A20130012051 (BK21Plus)).