کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4546707 | 1627061 | 2013 | 21 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A quantitative framework for understanding complex interactions between competing interfacial processes and in situ biodegradation A quantitative framework for understanding complex interactions between competing interfacial processes and in situ biodegradation](/preview/png/4546707.png)
In situ bioremediation of contaminated groundwater is made technologically challenging by the physically, chemically, and biologically heterogeneous subsurface environment. Subsurface heterogeneities are important because of influences on interfacial mass transfer processes that impact the availability of substrates to microorganisms. The goal of this study was to perform a “proof-of-concept” evaluation of the utility of a quantitative framework based on a set of dimensionless coefficients for evaluating the effects of competing physicochemical interfacial and biokinetic processes at the field scale. First, three numerical modeling experiments were completed, demonstrating how the framework can be used to identify the rate-limiting process for the overall bioremediation rate, and to predict what engineered enhancements will alleviate the rate-limiting process. Baseline conditions for each scenario were established to examine intrinsic biodegradation with a given rate-limiting process (either dispersion, biokinetics, or sorption). Then different engineering treatments were examined. In each case, the treatment predicted to be appropriate for addressing the overall rate-limiting process based on the quantitative framework alleviated the limitation more successfully, and enhanced the in situ biodegradation rate more than the alternative enhancements. Second, the quantitative framework was applied to a series of large-scale laboratory and field-scale experiments, using reported parameter estimates to calculate the relevant dimensionless coefficients and predict the rate-limiting process(es). Observations from the studies were then used to evaluate those predictions.
► Subsurface heterogeneities make in situ bioremediation technologically challenging.
► Heterogeneities induce mass transfer limitations of substrate availability.
► A dimensionless parameter framework compares mass transfer rates and biokinetics.
► Modeling experiments examine framework use to predict the rate-limiting process.
► Application to large-scale laboratory and field-scale experiments from the literature examine utility of the framework.
Journal: Journal of Contaminant Hydrology - Volume 146, March 2013, Pages 16–36