Adsorption of toxic crystal violet dye from aqueous solution by using waste sugarcane leaf-based activated carbon: isotherm, kinetic and thermodynamic study

The work demonstrated that waste sugarcane leaves were recycled by transforming them into activated carbon form and were employed for adsorption of crystal violet (CV) dyes from water bodies. Sugarcane leaves were ultrasonically treated with concentrated H2SO4 as an impregnating reagent and further with microwave irradiation for 15 min. The lustrous porous SLAC adsorbent material was subjected to characterized through advanced techniques like FTIR, XRD, BET, Raman, SEM, XPS, and EDAX analysis, to support and confirm the successful preparation of adsorbent and adsorption process. SLAC adsorbent shows the glowing porous and amorphous nature with fascinating specific surface area 730.59 m2 g−1. The porous and high surface SLAC adsorbent was utilized through batch adsorption technique for assessment and optimization of physico-chemical parameters viz. pH of working solution, SLAC amount, CV dye concentration, contact period, shaking speed, and surrounding temperature. At optimized conditions as pH 9.0 and 0.45 g SLAC significantly removed 99.81 ± 0.15% of toxic dye. Moreover, the equilibrium was attained within 60 min at a shaking speed of 170 rpm. The experimental data follows Langmuir adsorption isotherm with monolayer adsorption capacity 149.25 mg g−1. Kinetic study reveals that the adsorption process follows the pseudo-second-order kinetic model and thermodynamic study represents that the process is spontaneous and endothermic in nature.