Applied Biochemistry and Biotechnology

, Volume 84, Issue 1–9, pp 487–500 | Cite as

Effects of trace levels of copper, chromium, and zinc ions on the performance of activated sludge



The effects of copper, chromium, and zinc ions, at trace levels, on the performance of a simulated activated sludge process were investigated. The results of batch adsorption experiments showed that the adsorption of copper, chromium, and zinc ions followed both the Langmuir and Freundlich isotherms. The presence of trace levels of these three metals not only reduced the adsorption rate of organic matters but also the chemical oxygen demand adsorption capacity (CAC) of the activated sludge. Metal ions competed with the organic substrate for adsorption binding sites on the surfaces of activated sludge bioflocs and reduced the CAC. Studies performed in a sequential batch reactor (SBR) showed that the presence of trace levels of heavy metal ions in wastewater affected the SBR performance to different extents depending on the hydraulic retention time (HRT). When the reactors were operated at short HRTs of 2.5 d or less, the presence of trace levels of heavy metal ions reduced substantially the CAC of activated sludge, which, in turn, affected significantly the performance of the SBR. However, under longer HRTs (e.g., 5d), the heavy metal ions in the wastewater reduced the CAC but had not significant effect on the chemical oxygen demand removal efficiency.

Index Entries

Heavy metals chemical oxygen demand removal activated sludge adsorption capacity sequencing batch reactor 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Sawver, C. N., McCarty, P. I., and Parkin, G. F. (1994), Chemistry for Environmental Engineering, McGraw-Hill, Singapore, pp. 633–636.Google Scholar
  2. 2.
    Brown, M. J. and Lester, J. N. (1979), Water Res. 13, 817–837.CrossRefGoogle Scholar
  3. 3.
    Nelson, P. O., Chung, A. K., and Hudson, M. C. (1981), J. Water Pollut. Control Fed. 53, 1323–1333.Google Scholar
  4. 4.
    Battistoni, P., Fava, G., and Ruello, M. L. (1993), Water Res. 27(5), 821–827.CrossRefGoogle Scholar
  5. 5.
    Codina, J. C., Perez-Garcia, A., and de Vicente, A. (1994), Water Sci. Technol. 30 (10), 145–151.Google Scholar
  6. 6.
    Zarnovsky, L., Derco, J., Kuffa, R., and Drtil, M. (1994), Water Sci. Technol. 30(11), 235–242.Google Scholar
  7. 7.
    Suthirak, S. and Sherrard, J. H. (1981), J. Water Pollut. Control Fed. 53, 1314–1332.Google Scholar
  8. 8.
    Dilek, F. B., Gokcay, C. E., and Yetis U. (1998), Water Res. 23, 302–312.Google Scholar
  9. 9.
    Chang, S. Y., Huang, J. C., and Liu, Y. C. (1986), J. Environ. Eng. 112, 1, 94–104.CrossRefGoogle Scholar
  10. 10.
    Hong Kong Environmental Protection Department. (1998), Environment Hong Kong 1998—A Review of 1997, Hong Kong Government Printer, Hong Kong SAR.Google Scholar
  11. 11.
    Hong Kong Drainage Services Department. (1991), Technical Memorandum: Standards for Effluent Discharged into Drainage and Sowerage Systems, Inland Water and Coastal Waters, Hong Kong Government Printer, Hong Kong SAR.Google Scholar
  12. 12.
    Wong, K. Y., Zhang, M. Q., Li, X. M., and Lo, W. (1997), Biosens. Bioelectron. 12(2), 125–133.CrossRefGoogle Scholar
  13. 13.
    Tan, K. N. and Chua, H. (1997), Environ. Monitor. Assess. 44, 211–217.CrossRefGoogle Scholar
  14. 14.
    Tan K. N. (1993), MS thesis, National University of Singapore, Singapore.Google Scholar
  15. 15.
    Lo, W., Chua, H., Lam, K. H., and Bi, S. P. (1999). Chemosphere 39(15), 2723–2736.CrossRefGoogle Scholar
  16. 16.
    American Public Health Association. (1995), Standard Methods for the Examination of Water and Wastewater, 19th ed., American Public Health Association, Washington, DC.Google Scholar
  17. 17.
    Chong, H. K. and Volesky, B. (1995), Biotechnol. Bioeng. 47, 451–460.CrossRefGoogle Scholar

Copyright information

© Humana Press Inc 2000

Authors and Affiliations

  1. 1.Department of Civil and Structural EngineeringHong Kong Polytechnic UniversityHung HomHong Kong SAR
  2. 2.Union Laboratory of Asymmetric Synthesis and Department of Applied Biology and Chemical TechnologyHong Kong Polytechnic UniversityHung HomHong Kong SAR

Personalised recommendations