Enhanced chromium(VI) removal using banana peel dust: isotherms, kinetics and thermodynamics study

The present study highlighted a batch system to investigate the biosorption of Cr(VI) from aqueous solution by banana peel dust (BPD). BPD was characterized by pH_ZPC, SEM–EDX and FTIR studies. The percentages of adsorption and adsorption capacity were evaluated under different operating variables such as pH, adsorbent dose, initial concentration, contact time, stirring rate and temperature. The Cr(VI) ions adsorption was well explained using the Langmuir adsorption isotherm model, and the adsorption capacity was determined to be 26.46 mg/g. The kinetic study revealed that the uptake of Cr(VI) adsorption data fitted well with both pseudo-first-order and pseudo-second-order kinetic models with an activation energy of 1.56 KJ/mol. The values of free energy were negative under all temperatures studied, indicating that Cr(VI) adsorption in the presence of BPD is spontaneous. BPD could therefore serve as low-cost adsorbent to remove Cr(VI) from aqueous solution.