Details zur Publikation |
Kategorie | Textpublikation |
Referenztyp | Zeitschriften |
DOI | 10.1016/j.envsoft.2011.10.010 |
Titel (primär) | A reactive transport modeling approach to simulate biogeochemical processes in pore structures with pore-scale heterogeneities |
Autor | Gharasoo, M.; Centler, F.; Regnier, P.; Harms, H.; Thullner, M. |
Journal / Serie | Environmental Modelling & Software |
Erscheinungsjahr | 2012 |
Department | UMB |
Band/Volume | 30 |
Heft | 1 |
Seite von | 102 |
Seite bis | 114 |
Sprache | englisch |
Keywords | Biodegradation; Pore networks; Reactive transport models; Bioavailability; Pore-scale heterogeneity; Spatial distributions |
Abstract | Redox
processes, including degradation of organic contaminants, are often
controlled by microorganisms residing in natural porous media like soils
or aquifers. These environments are characterized by heterogeneities at
various scales which influence the transport of chemical species and
the spatial distribution of microorganisms. As a result, the
accessibility of the chemical species by the resident microbial
populations may be limited, altering the efficiency of the
biodegradation process. Hence, the biodegradation rate of contaminants
at large scales does not only depend on the degradation capacity of the
indigenous microbial population but also on the heterogeneities of the
hosting media at smaller scales. It is thus important to establish a
link between effective reaction rates and various structural features of
porous media which can be directly observed or measured. This link is
urgently needed because explicit resolution of heterogeneities within
large-scale reactive transport models is still limited by the available
computational capacities. The present study introduces a reactive transport modeling approach to determine the influence of pore-scale heterogeneities on biogeochemical processes in porous media. For this purpose, a pore network model, which simulates flow and advective–diffusive transport of chemical species in heterogeneous pore networks is developed and coupled to the Biogeochemical Reaction Network Simulator (BRNS). The resulting coupled model (PNBRNS) is able to simulate the reactive transport of solutes in heterogeneous pore assemblies. The PNBRNS model is applied for the simulation of a test case of bioavailability and effective biodegradation rate of a dissolved contaminant in different pore networks, built using a discrete set of geostatistically derived pore-size or biomass distributions. Results show that the heterogeneity of the pore-size distribution has a significant impact on bioavailability while the heterogeneity of the biomass distribution only leads to minor effects. The model also includes intra-pore bioavailability restrictions using diffusion-limited biodegradation kinetics. The results indicate that intra-pore limitations lead to extra constrains on the biodegradation of contaminants, even in the presence of larger-scale structural heterogeneities. |
dauerhafte UFZ-Verlinkung | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=11954 |
Gharasoo, M., Centler, F., Regnier, P., Harms, H., Thullner, M. (2012): A reactive transport modeling approach to simulate biogeochemical processes in pore structures with pore-scale heterogeneities Environ. Modell. Softw. 30 (1), 102 - 114 |