Bamboo sawdust-derived high surface area activated carbon for remarkable removal of paracetamol from aqueous solution: sorption kinetics, isotherm, thermodynamics, and regeneration studies
Wondimu Kebede Wakejo, Beteley Tekola Meshesha, Joon Wun Kang, Abayneh Getachew Demesa
Abstract
Abstract Due to its widespread consumption, paracetamol (PCT) has emerged as one of the leading contaminants that pollute water. Herein, a PCT removal of 99.6% was achieved using chemically activated carbon (CAC), derived from bamboo sawdust using KOH/FeCl3 as an activating agent, at optimal conditions of PCT (20 mg/L), CAC (0.5 g/L), contact time (90 min), and pH (8). Kinetic study revealed that the PCT adsorption process followed the pseudo-second-order kinetic model (R2 = 0.99), indicating that chemical adsorption dominated the adsorption mechanism. On the other hand, isotherm experimental data were best described by the Langmuir (R2 = 0.98) and Freundlich (R2 = 0.96) models. CAC had a maximum Langmuir monolayer capacity of 188.67 mg/g at a PCT concentration of 120 mg/L. Moreover, the Redlich–Peterson model gave the best fit (R2 = 0.99) to the experimental data, confirming that PCT adsorption was monolayer adsorption onto the heterogeneous surface. Thermodynamically, the PCT adsorption was exothermic, spontaneous, and favorable. The reusability study depicted that CAC can be successfully reused for five consecutive adsorption–desorption cycles. Furthermore, the application of CAC to environmental samples showed interesting results. The overall adsorption study indicated that CAC could serve as a promising adsorbent for eliminating PCT from water.