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(70-05) Modeling Contaminant Transport, Fate, and Ecological Risk Assessment. Fan, Ming*,1, Axe, Lisa1, Tyson, Trevor1, 1 New Jersey Institute of Technology, Newark, New Jersey ABSTRACT- As part of U.S. Department of Defense (DoD) "Sustainable Green Manufacturing" program, simulation tools are being developed for ecological risk assessment and evaluating contaminant mobility and bioavailability. The software includes three submodels: ecological risk assessment, speciation, and transport. The ecological risk assessment model (ERA-2001) includes a user-friendly interface, an interactive database management system (DBMS), and a comprehensive evaluation of exposure pathways. This ERA-2001 model was subsequently tested on a case study comparing risks from depleted uranium (DU) with other potential metals present at U.S. DoD firing ranges, such as chromium, molybdenum, and tantalum at the U.S. Army Aberdeen (APG) and Yuma (YPG) Proving Grounds. The results from this comparative assessment show that risks posed by DU for most of the terrestrial receptors at YPG are the highest among the four metals revealing adverse effects may potentially occur. At APG, risks from exposure to DU for all receptors fall into the least risk category - potential. Furthermore, molybdenum poses relatively greater risks for mammals, and for most of the aquatic species, chromium risks are the greatest among all metals, which fall in the slightly potential adverse risk category. As a result, field sampling at both sites centered around the firing ranges are recommended. The ERA-2001 is currently being linked with speciation and transport submodels to account for spatial and temporal aspects, which provide accurate assessment of contaminant mobility and bioavailability. MINEQL+® software is being used for obtaining speciation in the aqueous phase. The transport model will depict the slow sorption process of intraparticle diffusion as well as bulk transport and mixing processes, which supports advancing the ability of models to apply mobile and available concentrations found in the soil and subsurface environments. Key words: ecological risk assessment, transport modeling, depleted uranium, bioavailability |
