TITLE:
Competitive Adsorption of Metal Ions on Peanut Testa (Arachis hypogaea L.) Extract Using Cation Exchange Resins
AUTHORS:
Theresa Orieji Uchechukwu, Uche John Chukwu, Onyewuchi Akaranta
KEYWORDS:
Industry Wastewater, Peanut Testa Extract Polyphenols, Cation Exchange Resins, Heavy Metals, Adsorption
JOURNAL NAME:
Open Access Library Journal,
Vol.8 No.12,
December
16,
2021
ABSTRACT: Competitive adsorption of Fe2+, Ni2+, Pb2+, Cu2+ and Zn2+ in a multi-element solution was compared with the adsorption of the same in individual element solutions using cation exchange resins developed from modified peanut testa extract (PTE) as adsorbents. Modified PTE-polyphenols cation exchangers were prepared by first crosslinking with phosphorus oxychloride (POCl3) before functionalizing with chlorosulphonic acid (CSA). In another instance, PTE-polyphenols was only sulphonated using CSA. The produced resins were characterized by Fourier Transform Infrared (FTIR) spectroscopy, cation exchange capacity (CEC) and other properties. In addition to the FTIR absorption bands found in the 3400, 2900 and 1600 cm-1 regions of the electromagnetic spectrum showing the presence of -OH, -CH2 and -CH groups in the starting materials, which were also present in the spectra of the products, new bands due to -C-O-P=O, -P=O and R-O-P-OH stretching were observed at 1350, 1325, 1246 and 997 cm-1. Stretch bands due to -P-O-C- of aromatics, O=S=O and SO3H groups respectively created by phosphorylated, sulphonated and phosphosulphonated PTE were also found at 1278, 1190 and 1112 cm-1. The results showed that the CEC of Crosslinked-PPTE increased significantly from 6.7167 meq/g to 9.5267 meq/g after functionalization. The effect of the presence of a metal ion in the solution on the adsorption of another by the developed resins and a commercial ion exchange resin, Biorex 70 was investigated in terms of the amount of metal ions removed from the solutions.