Adsorption Isotherms and Kinetics of Heavy Metals Using H3PO4-Activated Carbon Derived from Oil Palm Fronds

Israyandi Israyandi (Department of Chemical Engineering, Faculty of Engineering, Universitas Muhammadiyah Riau, Pekanbaru, Indonesia)
Hendry Agustiyo (Department of Chemical Engineering, Faculty of Engineering, Universitas Muhammadiyah Riau, Pekanbaru, Indonesia)
Dwi Annisa Fithry (Department of Chemical Engineering, Faculty of Engineering, Universitas Muhammadiyah Riau, Pekanbaru, Indonesia)

Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Vol 70 No 2 (2026): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)

Toxic heavy metals in aquatic ecosystems pose serious environmental and ecological risks. This study evaluates the adsorption performance of H3PO4-activated oil palm frond biochar for removing Pb(II) and Cu(II) from a multi element system. Competitive adsorption was simulated using Certified Reference Material (CRM) containing 23 elements. The optimized adsorbent dosages were 0.05 g for kinetic experiments and 0.01 g for isotherm experiments, with metal concentrations of up to 10 mg/L in 25 mL of solution. Metal concentrations were analyzed using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES 5800 VDV). Kinetic analysis over 180 min showed that the adsorption process followed the pseudo-second order model, while equilibrium data were best described by the Langmuir isotherm, indicating selective adsorption toward competing metal ions. The adsorbent demonstrated high removal efficiencies for Fe, Al, Cu, Pb, and Cr, exceeding 80%. These results indicate that H?PO?-activated oil palm frond biochar has strong potential as an effective adsorbent for treating wastewater containing multiple hazardous heavy metals.