Removal of Heavy Metals Cd(ll) and Al(lll) from Aqueous Solutions by an Eco-Friendly Biosorbent

摘要

Heavy metals are very toxic water pollutants. Their presence not only affects human beings but also animals and vegetation because of their mobility in aqueous ecosystem, toxicity and non-biodegradability [1]. With the aim to remove heavy metals from aqueous solutions, an eco-friendly biosorbent was prepared from lagoon sludge by a humification process. The biosorption of Cd~(2+) and Al~(3+)ions from aqueous solutions was investigated as a function of initial pH, contact time, initial metal ions concentration, and temperature. Langmuir and Freundlich models were used to determine the sorption isotherm. Optimum pH for the removal of Cd(II) and Al(III) was found to be around 6 and 4, respectively [2]. The equilibrium was obtained in 60 min with the pseudo-second-order kinetic model. The Langmuir model was better fit with the experimental data for both Cd(II) and Al(III) adsorption with a regression coefficient up to 0.99 and Q_(max) of 100 and 142 mg.g~(-1), respectively.