Abstract:
The removal of nickel(II) and lead(II) ions from aqueous solutions was investigated using pumpkin peel biochar (PPB) prepared with sulfuric acid at ambient temperature. The effects of pH, contact time, dosage, and initial concentration of nickel(II) and lead(II) on the removal of the metal ions were studied. The removal of nickel(II) and lead(II) was highly dependent on the pH of aqueous solutions and the maximum adsorption occurred at pH 5.0. Nickel(II) and lead(II) adsorption reached to equilibrium conditions at 120 min. Increasing the initial concentration of nickel(II) and lead(II) resulted in an enhancement in the adsorbed quantities of the metal ions per gram of PPB, but the percentage of nickel(II) and lead(II) adsorbed decreased. The adsorption equilibrium of nickel(II) and lead(II) was compatible with the Langmuir isotherm model providing maximum monolayer adsorption capacities of 64.1 and 178.6 mg g(-1) for nickel(II) and lead(II), respectively. The nickel(II) and lead(II) adsorption kinetics represented well fit with pseudo-second-order kinetic model. It was concluded that the pumpkin peel carbon activated with sulfuric acid was highly effective for the removal of nickel(II) and lead(II) ions from aqueous solution.
