Removal of diesel oil from water using biochar derived from waste banana peels as adsorbent

Abstract

AbstractHere, banana peel biochar (BPBC) generated from discarded saba banana peels powder (SBPP) was utilized as an adsorbent in this study to remove diesel oil from water. The BPBC was synthesized using a slow pyrolysis method and characterized using SEM, EDX, FTIR, DSC, TGA, BET, contact angle analyzer, and XRD. The results showed that BPBC exhibited high porosity, thermal stability, and hydrophobic character, making it a promising adsorbent for oil-water separation and environmental remediation. The adsorption capacity of BPBC for diesel oil removal was examined in terms of adsorbent dose, pH level, salinity, and contact time. Increasing the BPBC dosage, contact time, and salinity significantly enhanced the sorption capacity, however, pH variations had no significant effect on adsorption. Adsorption parameters were correlated using a reduced cubic model, and an adsorbent dose of 2.50 g, pH of 7.00, salinity of 44,999.95 mg/L, and contact duration of 240 minutes were found to be optimal, producing a sorption capacity of 5.3352 g diesel oil/g adsorbent. The adsorption process was characterized by the first-order kinetic model. The creation of multilayer adsorption on the BPBC surface was confirmed by the BET isotherm. Adsorption characterization revealed changes in the surface morphology, elemental analysis, and functional groups of BPBC after adsorption. SEM revealed occupied surface pores, and EDX analysis verified an increase in carbon content. The presence of adsorbed diesel oil molecules on the BPBC surface was detected by FTIR analysis, which exhibited changes in peak appearance and functional group shifts. Overall, this study presents an adsorbent derived from waste material for diesel oil adsorption, which is useful for remediating oil spills and for wastewater treatment. Graphical Abstract