Abstract
Palm oil sludge (POS), an industrial waste from the palm oil industry, was utilised as a new adsorbent for the removal of toxic cadmium (Cd2+). Response surface methodology was carried out to investigate the effects of initial concentration (C0), contact time (t), dosage (W) and pH and optimise the process conditions. The maximum adsorption capacity was evaluated to be 18.49 mg g−1 at these optimised conditions: C0 = 200 mg L-1, t = 60 min, W = 0.3 g and pH 5.8. The adsorption equilibrium was achieved after 60 min, whereby the adsorption equilibrium and kinetic were best described by the Freundlich isotherm and pseudo-second-order kinetic models, respectively. The adsorption of Cd2+ onto POS was thermodynamically spontaneous (ΔG = -35.63 to -31.97 kJ mol−1), exothermic (ΔH = -35.92 kJ mol−1) with increased randomness at the solid–liquid interface (ΔS = 0.283 kJ mol−1 K−1). POS exhibited a high regeneration potential using 0.4 mol L-1 hydrochloric acid, with a desorption efficiency over 90% after 5 adsorption–desorption cycles. Conclusively, POS is an effective adsorbent for Cd2+ removal.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
