Mass transfer limitation of microbial growth and pollutant degradation

  • H Harms
  • T N P Bosma

Organic pollutants in soil can be removed by biotechnological treatment. A limitation of this technology is the efficiency of biodegradation. In many cases, the bulk of the pollution can be removed but residual pollutants remain and biodegradation rates are slower than expected from laboratory trials. Low biodegradation rates are often a result of limited accessibility of the pollutants. Major reasons for the reduced bioavailability are the unequal spatial distribution of microorganisms and pollutants and the retardation of substrate diffusion by the soil matrix. Mechanical mixing and the addition of surfactants are possible approaches to improve the bioavailability of pollutants during bioremediation. The application of flow-stop-flow techniques may be of help to overcome the limitations resulting from advective-diffusive transport mechanisms during pump-and-treat remediation of contaminant plumes.

Keywords: bioavailability; bioremediation; effective diffusivity; homogenization; mass transfer; surfactants 

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Copyright information

© Society for Industrial Microbiology 1997

Authors and Affiliations

  • H Harms
    • 1
  • T N P Bosma
    • 2
  1. 1.Swiss Federal Institute for Environmental Science and Technology (EAWAG), CH-8600 Dübendorf, SwitzerlandCH
  2. 2.Swiss Federal Institute for Environmental Science and Technology (EAWAG), Limnological Research Center, CH-6047 Kastanienbaum, SwitzerlandCH

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