Utilization of sugarcane bagasse ash as green adsorbent for Fuchsin basic dye removal

Sugarcane bagasse is generated in huge quantities worldwide which can be converted into high-end valuable products. A major portion of bagasse is converted into Sugarcane Bagasse Ash (SCBA) by burning it at a high temperature in industries. Proper utilization of SCBA instead of landfilling can reduce the harmful environmental effects. In this paper, application of bagasse ash as a green adsorbent for the removal of Fuchsin Basic (FB) dye was investigated. SCBA was characterized using XRD, FTIR, SEM-EDS, BET for insights into its properties. Parameters like contact time, pH, temperature, initial concentration and adsorbent dosage were varied and their impact on dye removal was studied. A maximum removal around 78% (for 10 mg/L dye concentration, 3 g/L adsorbent dosage, 7 pH, 60 min and 25 °C) was achieved using SCBA. Adsorption equilibrium was investigated and Langmuir model fitted best (q_max = 9.1706 mg/g and k_l= 0.1690 L/mg, R² = 0.9939) as compared to Freundlich and Temkin models. Additionally, kinetics studies revealed that Pseudo second order (R² = 0.9998) was superior over other kinetic models. Thermodynamic study confirmed the endothermic adsorption of FB on SCBA and FB removal of 50% was observed even after four cycles indicating reusability of adsorbent after regeneration. Use of SCBA directly as adsorbent without excessive pretreatment promises to be an attractive option.