A sugarcane bagasse carbon-based composite material to decolor and reduce bacterial loads in waste water from textile industry

Abstract

In present study, H3PO4–activated sugarcane bagasse carbon-based composite with Al(OH)3, was prepared and characterized by Brunauer-Emmett-Teller (BET), Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The adsorptive decolorization of methylene blue (MB) and methyl violet (MV) contaminated water employing sugarcane (Saccharum officinarum L.) bagasse carbon/Al(OH)3 {SBC/Al(OH)3} composite was explored under varying operational conditions. The equilibrium data for MB and MV adsorption was best appropriated by Langmuir and Freundlich isotherm models, respectively with the maximum Langmuir adsorption capacity of 261 mg/g for MB and 125 mg/g for MV illustrating the monolayer adsorption of MB onto energetically homogeneous sites and multilayer adsorption of MV onto heterogeneous surface sites. The kinetics of both MB and MV adsorption process onto SBC/Al(OH)3 composite was consistent with pseudo-second order model. The thermodynamic parameters such as ∆H° (5–17 kJ/mol for MB; 20–17 kJ/mol for MV) and ∆S° (0.063–0.1 kJ/mol.K for MB; 0.095 −0.21 kJ/mol.K for MV), and –∆G° (6.1–11.3 kJ/mol for MB; 12.4–30.0 kJ/mol for MV) advocated respectively the endothermic, increased randomness at the SBC/Al(OH)3–MB or MV interface, and spontaneous and feasible adsorption process. The adsorbent was efficiently regenerated and had the potential to be used for five recycles with limited loss in efficacy. The SBC/Al(OH)3 exhibited consistently good antibacterial activity against gram–negative (K. pneumonia; E. coli; P. aeruginosa) bacterial strains with zone of inhibition between 8 and 18 mm compared to gram–positive, B. cereus (6–13 mm). The apparent superiority of SBC/Al(OH)3 over other adsorbents in terms of adsorption capacity, promising reusability, and potent antibacterial properties demonstrated that SBC/Al(OH)3 composite could be a sustainable, remarkably efficient and cost-effective adsorbent for aquatic pollution abatement.