Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/12331
Title: Removal and recovery of heavy metals by bacteria isolated from activated sludge treating industrial effluents and municipal wastewater
Authors: Leung, WC
Wong, MF
Chua, H
Lo, WH 
Yu, PH
Leung, CK
Keywords: Adsorption
Bioremediation
Biosorption
Desorption
Heavy metals
Wastewater treatment
Issue Date: 2000
Source: Water science and technology, 2000, v. 41, no. 12, p. 233-240 How to cite?
Journal: Water Science and Technology 
Abstract: A total of nineteen metal-resistant and non-resistant bacteria from activated sludge treating both metal-contaminated industrial effluents and municipal wastewater were isolated and identified. These included both Gram-positive (e.g. Micrococcus) and Gram-negative (e.g. Pseudomonas) bacteria. The biosorption capacity of these strains for five different heavy metals (copper, nickel, zinc, lead and chromium) was determined at pH 5 and initial metal concentration 100 mg/L. Pseudomonas pseudoalcaligenes and Micrococcus luteus were found to be capable of removing significant amounts of copper and lead. Hence, they were selected for further investigations. Langmuir adsorption isotherms adequately represented the distribution of copper and lead for both species. The study of pH effect on metal removal for both species indicated that the metal biosorption increased with increasing pH from 2 to 6. The effect of competing cations on biosorption of P. pseuodoalcaligenes was studied. Sulphuric acid (0.05 M) was the most efficient desorption medium among the eleven reagents tested. Over 90% of copper sorbed on the cells of M. luteus could be recovered by washing with 0.05 M sulphuric acid within five minutes. The biosorbent was used for at least five biosorption and desorption cycles without loss of copper removal capacity. Immobilization of M. luteus in 2% calcium alginate and 10% polyacrylamide gel beads increased copper uptake by 61%.A total of nineteen metal-resistant and non-resistant bacteria from activated sludge treating both metal-contaminated industrial effluents and municipal wastewater were isolated and identified. These included both Gram-positive (e.g. Micrococcus) and Gram-negative (e.g. Pseudomonas) bacteria. The biosorption capacity of these strains for five different heavy metals (copper, nickel, zinc, lead and chromium) was determined at pH 5 and initial metal concentration 100 mg/L. Pseudomonas pseudoalcaligenes and Micrococcus luteus were found to be capable of removing significant amounts of copper and lead. Hence, they were selected for further investigations. Langmuir adsorption isotherms adequately represented the distribution of copper and lead for both species. The study of pH effect on metal removal for both species indicated that the metal biosorption increased with increasing pH from 2 to 6. The effect of competing cations on biosorption of P. pseudoalcaligenes was studied. Sulphuric acid (0.05 M) was the most efficient desorption medium among the eleven reagents tested. Over 90% of copper sorbed on the cells of M. luteus could be recovered by washing with 0.05 M sulphuric acid within five minutes. The biosorbent was used for at least five biosorption and desorption cycles without loss of copper removal capacity. Immobilization of M. luteus in 2% calcium alginate and 10% polyacrylamide gel beads increased copper uptake by 61%.The metal-biosorption behavior of metal-resistant and -nonresistant bacteria was characterized in an activated-sludge process treating both municipal and metal-contaminated industrial wastewater. The heavy metals of interest were copper, nickel, zinc, lead, and chromium. Subsequently, Pseudomonas pseudoalcaligenes and Micrococcus luteus, which were determined to be effective in removing metals, were studied further to assess the influence of initial metal concentration, pH, competing cations, desorption, and immobilization on their metal-biosorption capacities. The results showed that cells of M. luteus could be used for at least five alternate biosorption/desorption cycles without the loss of Cu-removal capacity, which was enhanced considerably when the cells were immobilized in 2% calcium alginate and 10% polyacrylamide gel beads. The presence of Cu decreased the amount of Pb adsorbed from solution. (from Netherlands Biotechnol Soc/et al 4th Int Symp on Environ Biotechnology, Noordwijkerhout (Apr 10-12, 00)).
Description: 4th International Symposium on EnvironmentaL Biotechnology (ISEB 4), Noordwijkerhout, Neth, 10-12 April 2000
URI: http://hdl.handle.net/10397/12331
ISSN: 0273-1223
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

94
Citations as of Apr 19, 2016

Page view(s)

34
Last Week
2
Last month
Checked on Jan 15, 2017

Google ScholarTM

Check



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.