Comparative study of Mangifera Indica peel to leaf as potential low cost adsorbent in removal of Chromium (VI) from aqueous solution

Abstract

This study proposed a comparative study of potential low-cost adsorbent; Mangifera Indica Peel (MIP) and Mangifera Indica Leaf (MIL) for removal of hexavalent Chromium, Cr (VI) in aqueous solution. Both adsorbents are prepared in the form of powder. The effect of contact time and adsorbent dosage, agitation speed and pH were studied in batch mode. The optimum adsorption of Cr (VI) from aqueous solution is at pH 3 for both MIP (97.42%) and MIL (91.79%). The best agitation speed for MIP and MIL are at 150 rpm. The value of correlation coefficient of Freundlich isotherm (R² =0.9993) is slightly higher than Langmuir isotherm (R² =0.9991) for MIP. While for MIL, the Freundlich (R² = 0.9981) was higher than Langmuir (R² = 0.9971). In the analysis, the MIP and MIL showed the best match for Freundlich isotherm. In the kinetic studies, both MIP and MIL obey the pseudo-second order with R² values at 0.9993 and 0.9984, respectively. The Fourier Transform Infrared (FTIR) analysis shows that functional groups present in the adsorbent helps in adsorption process of Cr (VI) ions. Both MIP and MIL shows their potential as low cost adsorbent in removing heavy metals, where MIP shows better performance than MIL.