Preliminary Adsorption Studies of Pb (II) With Gmelina Sawdust; Zn-Oxalic Acid (Zn-Oxa) and Cu-OXA MOFs

Abstract

This work is about sorption of Pb (II) with using Gmelina sawdust; Zn-OXA and Cu-OXA MOFs. Gmelina sawdust biosorbent was prepared by carbonization and subsequently activated; whereas, the MOFs sorbents were prepared using slow evaporation method. These materials were characterised using FTIR. The analyses revealed principally the presence of carboxyl, carbonyl, hydroxyl, and amine functional groups in the biomaterials; then hydroxyl and carbonyl for the MOFs. There was decrement in the FTIR absorption values of hydroxyl and carbonyl of the oxalic acid as observed in the spectra of the MOFs; implying that oxalic acid bonded to the Zn and Cu ions via O-H and C=O groups in the MOFs. The trend of sorption Pb (II) by these products is: Cu-OXA MOF (57%); Zn-OXA MOF (95%); uncarbonised sawdust (97%); and carbonized sawdust (99%). The presence of different functional groups (i.e. as listed above) of the sawdust sorbents and the MOFs is the reason they performed well in terms of the Pb (II) adsorption. However, the sawdust products and Zn-OXA MOF are more effective for the lead (II) removal than the Cu-OXA MOF.