Synthesis of activated carbon from banana peels for dye removal of an aqueous solution in textile industries: optimization, kinetics, and isotherm aspects

Abstract Treatment of harmful chemicals using materials at our disposal is the way forward. This study activated bio-adsorbent from waste banana for dye removal from an aqueous solution. The banana peel was activated both thermally and chemically with a preliminary study of a 0.5−2.5 M sulfuric acid concentration, and 50−90 °C of temperature for 1−5 h activation time. Activation at 1.5 M acid concentration, 70 °C for 3 h showed a promising efficacy of about 90% of removing dye. Activated banana peel was characterized using proximate analysis, BET, TGA, SEM, XRD, and FTIR. BET results showed activated banana peel to be porous material with a surface area of 432 m2/g. The adsorption capacity of the adsorbent with different variables range (adsorption time 20−140 min, pH 1.0−7.0, adsorbent dose 1−4 g/L and initial dye concentration 20−80 mg/L) was tested based on a preliminary study. The adsorption process was optimized numerically and the results were; adsorption time 60 min, pH 3, adsorbent dose 2 g/L and initial dye concentration 40 mg/L. The pseudo-second-order kinetics model and Langmuir isotherm model were the best fit to describe the adsorption process.