Study adsorption of Fe(II) by spent bleaching earth chitosan crosslinked epichlorohydrin composite

Abstract

Spent bleaching earth (SBE) is a solid waste generated from the crude palm oil (CPO) bleaching process. SBE has potential as an adsorbent; however, its adsorption capacity is relatively limited and requires enhancement. In this study, the adsorption capacity of SBE was improved by compositing it with chitosan. To enhance the stability of the adsorbent, the SBE–chitosan composite was crosslinked using epichlorohydrin (ECH). The resulting ECH crosslinked SBE–chitosan composite was evaluated for its ability to adsorb Fe(II) heavy metal ions. Fourier trans form infrared spectroscopy (FTIR) was employed to confirm the successful formation of the composite. Infrared spectra revealed interactions between the ECH-crosslinked SBE–chitosan composite and Fe(II) ions, indicated by shifts in wavenumbers and the appearance of new functional groups The results indicated that the composite was successfully synthesized, as evidenced by FTIR analysis. Optimal adsorption occurred at pH 5 with a contact time of 110 minutes. The adsorption behavior of the composite was Langmuir and Freundlich isotherm model, and the maximum adsorption capacity determined from Langmuir model was 11.23 mgg−1.