Adsorptive studies on the removal of dyes from single and binary systems using Saccharum munja plant-based novel functionalized CNT composites

Abstract

Herein, Saccharum munja (SM) plant biomass and its novel composites with 0.5%, 1% and 2% functionalized carbon nanotube (CNT) were innovatively proposed as a versatile biosorbent for the removal of safranine O (SO) and methylene blue (MB) dyes from the single and binary systems. The morphology, structure and physicochemical properties of the as-fabricated adsorbents were characterized using various techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscope (FESEM) and Differential Scanning Calorimetry (DSC). Batch adsorption studies revealed maximum removal of dyes at neutral pH and equilibrium was reached within 10 min of contact time for both the dyes. The adsorption process was modelled by the pseudo-second-order kinetics and Langmuir isotherm, where the maximum adsorption capacity of the 1%CNT+SM composite was enhanced by 336.29% and 35.49% as compared to raw SM, in the case of SO and MB dye respectively. Interestingly, the raw SM and its composites showed a higher affinity in the binary system towards the removal of SO (82.56-95.67%) as compared to MB (80.67-94.24%) dye. Regeneration studies depicted excellent reusability even after the tenth sequential adsorption–desorption cycle, which makes these adsorbents a promising material for wastewater remediation.