the potential of citrobacter freundii, a gram negative bacteria for the remediation of hexavalentchromium (cr(vi)) and trivalent chromium (cr(iii)) from aqueous solutions was investigated. bioremediationof cr(vi) involved both biosorption and bioreduction processes, as compared to only biosorption processobserved with respect to cr(iii) bioremediation. in the case of cr(vi) bioremediation studi...