Simplified synthesis of bentonite/gelatin and bentonite/sucrose composites for efficient removal of anionic and cationic dyes

Bentonite-gelatin (BT-Ge) and bentonite-sucrose (BT-Su) composites were fabricated using a simple solution mixing method and employed as adsorbents for extracting dyes from aqueous solutions. The structural characteristics of the fabricated composite materials were elucidated using x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA). The adjustable adsorption capabilities of the developed adsorbents toward methyl red (MR) and methylene blue (MB), representing anionic and cationic dyes, respectively, were examined by varying the mass ratio of bentonite to gelatin and sucrose. The impact of contact time, adsorbent dosage, and pH on the adsorption process of MR and MB onto BT-Ge and BT-Su was investigated. Kinetic data fitting indicated a good agreement with the pseudo-second-order model, with equilibrium typically achieved within 30 min, resulting in 99.69 +/- 0.550, 99.56 +/- 0.344, 99.90 +/- 0.488% removal of MB with BT, BT-Su, and BT-Ge, respectively and 99.50 +/- 0.854, 99.50 +/- 0.658, and 99.57%+/- 0.501% of MR with BT, BT-Su, and BT-Ge, respectively from the aqueous solutions. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models, with the Langmuir model showing the best fit and indicating a maximum adsorption capacity of 666.66 mg g-1 of MR and 285.71 mg g-1 of MB at 25 degrees C. These findings underscore the remarkable efficacy of BT-Ge and BT-Su composites in eliminating dyes from wastewater, particularly colored effluents.