Volatilization of Mercury by Immobilized Bacteria (Klebsiella pneumoniae) in Different Support by Using Fluidized Bed Bioreactor

Abstract

Klebsiella pneumoniae, a mercury-resistant bacterial strain able to reduce ionic mercury to metallic mercury, was isolated from wastewater of Casablanca. This strain exhibits high minimal inhibition concentrations for heavy metals such as mercury 2400 microM, lead 8000 microM, silver 2400 microM, and cadmium 1000 microM. This bacterium was immobilized in alginate, polyacrylamide, vermiculite, and cooper beech and was used for removing mercury from a synthetic water polluted by mercury by using a fluidized bead bioreactor. Immobilized bacterial cells of Klebsiella pneumoniae could effectively volatilize mercury and detoxify mercury compounds. Moreover, the efficiency of mercury volatilization was much greater than with the native cells. The highest cleanup and volatilization rates were obtained when Klebsiella pneumoniae was entrapped in alginate beads, with a cleanup rate of 100% and a volatilization rate of 89%. Immobilized cells in alginate continuously volatilized mercury even after 10 days without loss of activity.

Potential of Mercury-Resistant Marine Bacteria for Detoxification of Chemicals of Environmental Concern

“…Roane et al 38) reported that R. eutropha JMP134, a 2,4-D degrader which was sensitive to Cd, could degrade 2,4-dichlorophenoxyacetic acid even in the presence of Cd when it was grown in a consortium with Cd-detoxifying bacteria. Zeroual et al 48) observed that a strain of Klebsiella pneumoniae could tolerate 2400 µM of mercury and 1000 µM of cadmium. The resting cells of P. aeruginosa PU21 (Rip64) have been reported to take up upto 110 mg Pb/g dry cell mass whereas, the inactivated cells could absorb 70 mg Pb/g dry cell 12) .…”

Evaluation of Consortia of Microorganisms for Efficient Removal of Hexavalent Chromium from Industrial Wastewater

“…Several studies have reported improvements in metal removal by immobilization of protozoa, yeast or bacterial cells (Zeroual et al 2001). Bacteria and yeast communities are central to the functioning of terrestrial ecosystem and consist of a large number of different bacterial and yeast type (O-Muter et al 2002;Boenigk and Arndt 2000).…”

Decolorization of Azo Dyes by Immobilized Bacteria

“…Most dyes have long been considered nonbiodegradable or nontransformable under aerobic conditions [35]. Zeroual et al (2001) [49] used bacterial strain Enterobacter agglomerans on different support materials by using fluidized bed reactor (FBR) and found that the bacteria had high effectiveness of decolorization of water polluted with azo dye methyl red. The immobilized cells of E. agglomerans exhibited higher capability for the complete decolorization of methyl red (100 mg/L) after 6 h of incubation under aerobic condition.…”

“…Immobilization of microorganism has been reported useful in biological wastewater treatment [47][48][49][50]. There are various methods of immobilization of bacterial cells.…”