Using Iranian Bentonite (Birjand Area) to Remove Cadmium from Aqueous Solutions

作者：Sadeghalvad B; Armaghan M; Azadmehr A^*

来源：Mine Water and the Environment, 2014, 33(1): 79-88.

DOI：10.1007/s10230-013-0253-5

• Adsorption
• Kinetics
• Thermodynamics
• Isotherm

Bentonite from the Birjand area of Iran was characterized by X-ray diffraction, X-ray fluorescence, and Fourier transform infrared spectroscopy. The removal of cadmium from aqueous solution by this bentonite was investigated as a function of conditions such as contact time, metal concentrations, pH, stirring speed, temperature, particle size, and amount of bentonite. The adsorption isotherm was studied with different models: the Freundlich and Dubinin-Radushkevich models had the highest correlation coefficients, 0.9922 and 0.9988, respectively. The corresponding Langmuir model indicates a maximum adsorption capacity of 13.50 mg/g. First-order, pseudo-second-order, and intra-particle diffusion equations were used to study the mechanism of adsorption; the experimental data fit well with pseudo-second-order kinetics. Thermodynamic parameters of adsorption were calculated at temperatures of 293, 303, 313, and 323 K, and indicated that the Cd adsorption was exothermic and spontaneous.

• 出版日期2014-3