Experimental Research on Adsorption of Cadmium with Synthetic Tobermorite from Wastewater
Tobermorite nano-scale powder was synthesized from potassium feldspar ore from Henan province Lushi country in China. In the present research work, its adsorption property to Cd2+ was studied. The factors of adsorption such as pH values, traction time, initial concentration, and temperature were studied. The adsorption equation was curvefitted by the Langmuir and Freundlich adsorption isotherm and the thermodynamics adsorption was analyzed. By the orthogonal experiment and single-factor experiment of the adsorption, the optimized conditions of the adsorption for Cd2+ were achieved: the reaction temperature is 40°C, the reaction time is 20 min, the initial concentration of aqueous solution is 20 mg•L-1 and pH value is 6.0. Under these conditions the adsorption efficiency of Cd2+ can reach 99.89%. The orthogonal experimental results show that the order of effect on adsorption efficiency was the initial concentration, pH value, reaction temperature, reaction time. In different temperatures, the results show that isothermal Langmuir equation can describe the isothermal adsorption characteristics of Cd2+ on tobermorite. Thermodynamic parameters can be drawn: the G was negative and with increasing temperature H increased, so the adsorption process is a spontaneous reaction to the heat.
Guojun Zhang and Jessica Xu
H. B. Qi et al., "Experimental Research on Adsorption of Cadmium with Synthetic Tobermorite from Wastewater", Advanced Materials Research, Vols. 160-162, pp. 1038-1043, 2011