Removal of hexavalent chromium in contaminated water using banana peel (Paradisiac musea) as adsorbent

Abstract

This research aimed to remove the hexavalent chromium from contaminated water using the banana peel as an adsorbent. The study was realized in two stages: in the first stage, it worked with 1 g of the biomass at a particle size of approximately 600 µm, 5 minutes of contacts, 20 mg.l^-1  of hexavalent chromium and at pH 3, 3,5, 5 and 7. In the second stage, it worked with the mass and time conditions at pH 3 and 3.5, increasing the metal concentration from 20 to 40 and 80 mg.l^-1. The results obtained show that increasing the pH reduces the removal percentage and the adsorption capacity, however, at pH 3 and 3,5 the biomass removes almost 100% of the hexavalent chromium and increasing the concentration increases the adsorption capacity of the banana peel. The experimental data fit more to the Langmuir model than to the Freundlich model, which shows monolayer adsorption of a homogeneous surface. Also, the separation factor R_L was between 0,809 and 0,383 which indicated favorable adsorption of the heavy metal in the biomass. The banana peel has great potential as an adsorbent for the removal of hexavalent chromium in water.