REMOVAL OF HEXAVALENT AND TOTAL CHROMIUM FROM AQUEOUS SOLUTIONS BY Schinus molle BARK

摘要

The main purpose of this work was to evaluate the potential of Schinus molle bark to remove hexavalent chromium [Cr(VI)] and total chromium from aqueous solutions. Results showed that Schinus molle bark removed Cr(VI) by two different mechanisms: chromium biosorption and bioreduction of Cr(VI) to Cr(III). The capacity for removing Cr(VI) and total chromium gradually increased as the contact time proceeded, reaching values of 97.56 and 73.18 mg g~(-1) respectively, after 120 h. The opposite behavior was observed concerning the volumetric rates of Cr(VI) and total chromium removal. The pseudo-second order model adequately described the kinetic process of chromium biosorption by Schinus molle bark, which suggests that this process chiefly occurs as a result of chemisorption.