Adsorptive Removal of Hexavalent Chromium by Activated Carbon Prepared From Enset Root (Enset Ventricosum)

Abstract

The presence of chromium (VI) ions in water is extremely harmful because it can cause illnesses, disorders and diseases to humans. Recently, the use of different technologies to remove this contaminates is investigated. In this study the investigated performance of agricultural waste (Enset root) as a novel, natural, low-cost, and alternative adsorbent for removal Cr(VI) ion from wastewater within a batch adsorption process. Enset root was carbonized and activated by treating with H2SO4 solution followed by heating in an electrical furnace at 500 0C for 3 h. The prepared adsorbent was characterized using FTIR and XRD before and after adsorption. The effect of various experimental parameters was examined such as contact time, initial concentration, pH, adsorbent mass, and temperature. The adsorption capacity was 130 mg/g at Ph 1 using 0.6 mg/L of adsorbent in 50 mg/L chromium solution. The result data was well fitted to pseudo-second-order for kinetics and Langmuirm and Redlich-Peterson for the isothermal model study. Thermodynamic properties ( G0, ∆H0 and ∆S0) of the adsorption were determined at different temperatures. Further, the adsorption cycle study showed the material was efficiently reused for five successive cycles, and the effect of co-existing ions on the adsorption of Cr(VI) ions was evaluated. The obtained results indicated that this Enset root was very good adsorbent for the removal of Cr(VI) ion , interesting alternative material with respect to more costly adsorbent used , and could be used as a highly efficient adsorbent for the removal of chromium ion from wastewater. This research was done on a lab scale using batch adsorption methods, and with simple activation. Further, studies can use other modification methods to activate this adsorbent for chromium removal and other heavy metals, and to be extended in continuous column mode on real wastewater to promote large-scale application of the biosorbents.