Biosorption of copper and lead ions onto treated biomass Myrica esculenta: Isotherms and kinetics studies

Abstract

Copper and lead ions in polluted water sources pose grave ecological and health concerns to all living things. The processed biomass of Myrica esculenta was utilised as a biosorbent to remove copper and lead ions from wastewater. Biosorption evaluation was impacted by operating variables such as pH (1.0 to 7.0), metal ion concentration (10 to 50 mg/L), biomass concentration (1 to 5 g), contact time (15 to 75 min), and temperature (25 to 65 °C). The copper and lead ion sorption study was carried out using a batch sorption system. At pH 4.0, the highest biosorption efficiencies of Myrica esculenta for CuII and PbII were found to be 94.9 % and 90.2 %, respectively. Studies on biosorption indicated that pseudo-second-order models more accurately described kinetic data. Regarding the biosorption isotherm, the Langmuir model was the best applicable model for experimental data. On Myrica esculenta the maximum observed adsorption capacity Qmax for PbII ions is 43.86 mg/g, while the maximum observed adsorption capacity Qmax for CuII ions is 39.37 mg/g. The FTIR findings of Myrica esculenta biomass indicated that there were hydroxyl (OH), amine (NH), carbonyl (CO) and carboxylic (COOH) functional groups on biomass. These functional groups interact with the metal ions in synthetic wastewater. Under examined conditions, the biosorption of CuII and PbII ions on Myrica esculenta biomass was found spontaneous (ΔG0 < 0), endothermic (ΔH0 > 0), and feasible (ΔS0 > 0) according to the computed thermodynamic parameters ΔG0, ΔH0 and ΔS0.