Indonesian Kesambi wood (Schleichera oleosa) activated with pyrolysis and H₂SO₄ combination methods to produce mesoporous activated carbon for Pb(II) adsorption from aqueous solution

The presence of lead in the aquatic environment is a problem with a high potential negative impact on human health. To overcome the lead problem in an aqueous environment, here for the first time we report about the use of kesambi wood (Schleichera oleosa) as a precursor to preparing activated carbon-based adsorbents. Here, the precursor material is prepared to become graphite or Non-Activated Carbon Mesoporous Adsorbents (NACMA) by using the pyrolysis method. NACMA then was chemically activated by using H₂SO₄ to produce Activated Carbon Mesoporous Adsorbent (ACMA) material. The characteristics of the ACMA and the NACMA then were evaluated by using the FTIR, XRD, SEM-EDX and BET-BJH instruments. ACMA then is used to adsorb Pb(II) from an aqueous solution by using a batch system. In this study, 10 kinetics models and 5 adsorption isotherm models were used to study the Pb(II) adsorption mechanism. The results of the kinetic analysis showed that the adsorption of Pb(II) on activated carbon mesoporous adsorbent (ACMA) was following the pseudo-second-order (PSO) model. Meanwhile, the adsorption isotherm follows the Langmuir model with an adsorption capacity of 1.634 mg.g⁻¹. Thermodynamic analysis shows that the adsorption process occurs exothermic and physisorption. In addition, there was also a decrease in the degree of irregularity on the surface of the activated carbon mesoporous adsorbent (ACMA) adsorption system during the adsorption process.