Abstract
The effect of hexavalent chromium, Cr(VI), on the maximum specific growth rate, μ m and biomass yield, Y H, of heterotrophic biomass was studied in batch tests conducted under high (=10) and low (=1.5) substrate-to-biomass ratios ( S 0/ X 0). The effects of sludge age and biomass acclimatization to Cr(VI) on the bacterial kinetics were also studied. The μ m values were determined by measuring oxygen uptake rate (OUR) and volatile suspended solids (VSS) increase. Cr(VI) concentrations equal or greater than 10 mg l −1 inhibited the growth of unacclimatized activated sludge and caused a significant decrease in μ m and Y H values. The acclimatization of biomass and the selection of a high operating sludge age reduced the inhibitory effect of Cr(VI). At a sludge age of 20 days, Cr(VI) concentrations of <10 mg l −1 stimulated bacterial growth as evidenced by an increase in both the μ m and Y H values. Determining μ m values by OUR and VSS methods, revealed that the presence of Cr(VI) in unacclimatized biomass caused an inhibitory effect mostly on substrate oxidation, while in acclimatized biomass, anabolic pathways were inhibited more.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
