Adsorption of lead (ii) and copper (ii) from aqueous solution using biochar derived from coconut shell / Nur Liyana Mat Azlan

The demand for safe and clean water has increased by leaps and bound due to the higher number of heavy metals such as lead and copper that will pollute water. In this study, biochar derived from coconut shell was used for adsorption of lead and copper from an aqueous solution. Batch adsorption experiments were done to study the effect of several parameters such as pH (2, 3, 4, 5 and 6), contact time (15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180 min), adsorbent dose (0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 g) and temperature (30, 40, 50 and 60 °C). Maximum adsorption of lead and copper has been obtained at pH 5, 150 min contact time, at an adsorbent dose of 1.0 g and a temperature of 60 °C. The data from adsorption kinetics were used to examine the feasibility of two models: pseudo-first order kinetic and pseudo-second order kinetic. The data was well-fitting to the pseudo-second order model. The Langmuir and Freundlich isotherms were used to fit the equilibrium data and the Langmuir isotherm model with maximum monolayer adsorption capacity for lead and copper are 9.1659 mg/g and 3.9262 mg/g at 25°C best described the equilibrium data. This study shows that BC can be effective at removing lead and copper from water.