Chromium (VI) removal in aqueous solution by the modified biomass of rice grain (Oriza sativa L.)

Abstract

It was studied the removal capacity of Chromium (VI) in an aqueous solution by the modified biomass of rice grain, using the diphenylcarbazide colorimetric method, to evaluate the metal concentration. The biosorption at different pHs (1, 2, 3, and 4) was evaluated at different times. Too, the effect of temperature in the range of 28 to 60 °C and removal at different initial concentrations of Cr (VI) from 200 to 1 000 mg/L, were studied. The most removal of metal, was eight days, with 100 and 79 %, for both biomasses, modified and not modified, respectively, at 28 °C, pH 1.0, and 1 g of biomass. Concerning the incubation temperature, the highest removal was at 60 °C, with 100 % of removal after five days. Additionally, the biomass concentration does influence the metal removal, and efficiently remove the metal from contaminated earth and wastewater (71 and 73 %, respectively), after 10 days of incubation with 10 g of biomass.