Removal of Lead and Chromium From Industrial Wastewater by LocallyCitrobacter spp.Isolates

Abstract

Biosorption is an effective method to remove toxic metals from wastewaters. In this
study biosorption of lead and chromium ions from solution was studied using
Citrobacter freundii and Citrobacter kosari isolated from industrial wastewater. The
experimental results showed that optimum grwoth temperature for both bacteria is 30oC
and the optimum pH is 7 &6 for C. freundii and C. kosari respectively. While the
optimum incubation period to remove Pb and Cr for C. freundii and C. kosari is 4 days
and 3days respectively. Also the biosorption of Pb and Cr in mixed culture of bacteria
and mixed culture of Pb and Cr was investigated. Result indicate that uptake of Cr and
Pb for C.freundii, C. kosari and in mixes culture of both bacteria is 58%, 53% and 82%
respectively for chromium in solution containing 1000ppm of Cr and 59%, 63% and
78% respectively for lead in solution containing 1000ppm of lead. But the uptake
decreases in solution containing both heavy metals lead and chromium.