Equilibrium and kinetic studies of uptake of nickel in aqueous solution

The uptake of Ni (II) ions from aqueous solution by biochar composed of may flower seed carbon (MFSC), produced by the thermal activation of may flower seed, under inert condition at 400 degrees C for 1 h, was studied. The effect of pH, contact time and adsorption dose on the adsorption of Ni (II) ions by MFSC and the optimization of removal of Ni (II) ions from aqueous solution were investigated by batch adsorption studies. The results obtained gave a maximum adsorption capacity for Ni (II) ions at pH 6, exposure time of 40 min, and dosage of 200 mg/50 mL at 27 degrees C. Analysis of kinetic data showed that the adsorption process of Ni (II) ions followed pseudo-second-order kinetics. Adsorption isotherms were used for determination of MFSC adsorption type and capacity and the Langmuir model was found to be well adapted to describe the adsorption of NI (II) ions, while poor fitting of the experimental data was observed with Freundlich and Temkin isotherm models. The extent of desorption of Ni (II) ions from MFSC under acidic condition was determined to be 45.16%. The results demonstrated the feasibility of using may flower seed carbon in the treatment of Ni (II) ions polluted electroplating industry effluent.