Removal of Methylene Blue Dye from Aqueous Solutions by Bentonite and Cement Kiln Dust: Comparative Study of Adsorption Equilibrium, Kinetic, and Thermodynamic | ||
| Alexandria Science Exchange Journal | ||
| Article 5, Volume 42, Issue 3, September 2021, Pages 629-644 PDF (854.15 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/asejaiqjsae.2021.186823 | ||
| Author | ||
| Ahmed Abd El Khalek El Refaey* | ||
| Department of Soil & Water Science, Faculty of Desert and Environmental Agriculture, Matrouh University, Egypt | ||
| Abstract | ||
| This study compared the methylene blue (MB) removal from aqueous solution by natural bentonite (Bent) and cement kiln dust (CKD). Bentonite and CKD were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), Brunauer Emmett Teller (BET) specific surface area, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). The comparison between bentonite and CKD in the removal of MB dye was investigated in different conditions including initial MB concentration, adsorbent doses, pH, salt concentration, and temperature by batch experiments. Adsorption kinetics results were fitted with fractional power, Elovich, pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations. The pseudo-second-order model was well fitted for experimental results at the different tested initial concentrations (50-300 mgMB/L). Equilibrium adsorption data were evaluated by Freundlich and Langmuir and Temkin models. The experimental results fitted very well by the Langmuir isotherm model. Bentonite exhibited the largest adsorption capacity (3257.33 mg/g) than CKD (2150.54 mg/g). Increasing the temperature from 298K to 323 oK convinced an increase of the adsorption of MB dye by both sorbents and the process was found to be endothermic and spontaneous. The obtained results indicated that both adsorbents are efficient and low-cost adsorbents for effective removal of MB dye with privilege in the efficiency for bentonite and with no cost for CKD. | ||
| Keywords | ||
| Bentonite; Cement Kiln Dust; methylene blue; kinetic and adsorption isotherm; Thermodynamic | ||
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