Thermodynamic and Kinetic Studies of Effective Adsorption of 2,4,6-trichlorophenol onto Calcine Mg/Al-CO_3 Layered Double Hydroxide

Adsorption of 2, 4, 6-trichlorophenol(TCP) onto the calcined Mg/Al-CO_3 layered double hydroxide(CLDH) was investigated. The prepared Mg/Al-CO_3 layered double hydroxide(LDH) and CLDH were characterized by powder X-ray diffraction(XRD) and thermo gravimetric analyzer-differential scanning calorimeters(TG-DSC). Moreover, 2,4,6-trichlorophenol(TCP) was removed effectively(94.7% of removal percentage in 9h) under the optimized experimental conditions. The adsorption kinetics data fitted the pseudosecond-order model well. The Freundlich, Langmuir, and Tempkin adsorption models were applied to the experimental equilibrium adsorption data at different temperatures of solution. The adsorption data fitted the Freundlieh adsorption isotherm with good values of the correlation coefficient. A mechanism of the adsorption process is proposed according to the intraparticle diffusion model, which indicates that the overall rate of adsorption can be described as three steps.