Physico-Thermally Modified Chrysophyllum albidum Seed Shell Activated Carbon for Removal of Malachite Green Dye from Simulated Wastewater

Abstract

The objective of this paper was to physico-thermally modify Chrysophyllum albidum seed shell (CASS) to Chrysophyllum albidum seed shell activated carbon (CASSAC) for removal of malachite green dye from simulated wastewater using isotherm, kinetic, and thermodynamic models after applying appropriate standard techniques. The result of physico-thermal treatment of CASS to CASSAC showed that the modification of CASS increases total pore volume to 0.522 cm³/g, average pore size to 24.22 Å and surface area to 1450.20 m²/g. The maximum dye removal efficiency was 80.12% at experimental conditions of (initial dye concentration - 50 mg/L, CASSAC dosage - 0.30g, pH 8, and agitation time - 60 min). The Temkin and pseudo-first-order models best fit the data, indicating homogeneous monolayer adsorption driven by physisorption. Thermodynamic study showed adsorption is feasible, spontaneous, and endothermic. On the other hand, the reusability study was carried out and the adsorbent was utilized in three cycles with a drop in the removal efficiencies from 80.0 to 58.9% after the third cycle usage. This study concludes that CASSAC effectively removes malachite green dye from wastewater through adsorption, offering a cost-effective, sustainable, and environmentally friendly solution for textile wastewater treatment.