Alginate based metal pillared bentonite beads for efficient adsorption of cationic dyes

Abstract

Abstract Three pillared bentonite composites, namely Aluminium Pillared Clays-Beads (Al-PCB), Iron Pillared Clays-Beads (Fe-PCB) and Tin Pillared Clays-Beads (Sn-PCB) were prepared. The synthesized adsorbent beads were characterized using X-ray diffraction (XRD), Fourier Transform Infrared spectra (FT-IR), Brunauer-Emmer Teller (BET) analysis, Thermogravimetric analysis (TGA), and Scanning Electron Microscopy (SEM). The adsorption capacity of prepared adsorbents was examined for two dyes viz. Malachite Green (MG) and Chrysoidine-Y (CY) from their aqueous solutions. Batch adsorption studies were conducted to assess the dye removal capacity of all three adsorbents. The effects of physicochemical parameters like solution pH, dose, and dye concentration were investigated. Thermodynamic studies of prepared beads were carried out at different temperature. The adsorption capacity of Al-PCB, Fe-PCB and Sn-PCB was found to be 130.734 mg g− 1, 95.827 mg g− 1 and 47.965 mg g− 1 for MG and 118.678 mg g− 1, 90.348 mg g− 1 and 36.706 mg g− 1 for CY respectively. On the other hand, fitting of PSO model was slightly better than PFO model. Regeneration studies revealed that the dye removal percentage ranged from 60–93%, up to five adsorption desorption cycles.