, Volume 22, Issue 5, pp 877–896 | Cite as

Dimensionless parameters to summarize the influence of microbial growth and inhibition on the bioremediation of groundwater contaminants

  • M. Mohamed
  • K. Hatfield
Original Paper


Monod expressions are preferred over zero- and first-order decay expressions in modeling contaminants biotransformation in groundwater because they better represent complex conditions. However, the wide-range of values reported for Monod parameters suggests each case-study is unique. Such uniqueness restricts the usefulness of modeling, complicates an interpretation of natural attenuation and limits the utility of a bioattenuation assessment to a small number of similar cases. In this paper, four Monod-based dimensionless parameters are developed that summarize the effects of microbial growth and inhibition on groundwater contaminants. The four parameters represent the normalized effective microbial growth rate (η), the normalized critical contaminant/substrate concentration (S*), the critical contaminant/substrate inhibition factor (N), and the bioremediation efficacy (η*). These parameters enable contaminated site managers to assess natural attenuation or augmented bioremediation at multiple sites and then draw comparisons between disparate remediation activities, sites and target contaminants. Simulations results are presented that reveal the sensitivity of these dimensionless parameters to Monod parameters and varying electron donor/acceptor loads. These simulations also show the efficacy of attenuation (η*) varying over space and time. Results suggest electron donor/acceptor amendments maintained at relative concentrations S* between 0.5 and 1.5 produce the highest remediation efficiencies. Implementation of the developed parameters in a case study proves their usefulness.


Modeling Bioremediation Monod kinetics Inhibition Dimensionless Groundwater 



This research was partially funded by the Environmental Remediation Science Program (ERSP), U.S. Department of Energy: (Grant Number DE-FG02-08ER64585) and the Research Affairs at the UAE University (Grant number 08-01-7-11/09).


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© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.Civil and Environmental Engineering DepartmentUnited Arab Emirates UniversityAl-AinUAE
  2. 2.Irrigation and Hydraulics Department, Faculty of EngineeringCairo UniversityGizaEgypt
  3. 3.Civil and Coastal Engineering DepartmentUniversity of FloridaGainesvilleUSA

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