Sitte J.,Friedrich - Schiller University of Jena |
Akob D.M.,Friedrich - Schiller University of Jena |
Akob D.M.,Florida State University |
Kaufmann C.,Friedrich - Schiller University of Jena |
And 9 more authors.
Applied and Environmental Microbiology | Year: 2010
Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB In groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the 35SO4 2- radiotracer method, was restricted to reduced soil horizons with rates of ≤142 ± 20 nmol cm-3 day-1. Concentrations of heavy metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that ∼80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone libraries were dominated by sequences affiliated with members of the Desulfobacterales but also the Desulfovibrionales, Syntrophobacteraceae, and Clostridiales. [13C] acetate- and [ 13C] lactate-biostimulated soil microcosms were dominated by sulfate and Fe(III) reduction. These processes were associated with enrichment of SRB and Geobacteraceae; enriched SRB were closely related to organisms detected in soils by using the dsrAB marker. Concentrations of soluble nickel, cobalt, and occasionally zinc declined ≤100% during anoxic soil incubations. In contrast to results in other studies, soluble uranium increased in carbon-amended treatments, reaching ≤ 1,407 nM in solution. Our results suggest that (i) ongoing sulfate reduction in contaminated soil resulted in in situ metal attenuation and (ii) the fate of uranium mobility is not predictable and may lead to downstream contamination of adjacent ecosystems. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Heravi M.,Institute for Biological science |
Heravi M.,University of Economic Sciences |
Akramizadeh A.,Amirkabir University of Technology |
Pourakbar M.,University of Economic Sciences |
Menhaj M.B.,Amirkabir University of Technology
13th Iranian Conference on Fuzzy Systems, IFSC 2013 | Year: 2013
Decision making is an important problem in most of the army operations. One of the challenging issues in this area is uncertainty in wars with uncertain information which causes many destructive effects on the results of strategies in battlefields. Cognitive Agent (CA) brings about an improvement by reducing the uncertainties meanwhile causes some unavoidable negative effects in critical decisions. Classification based on Fuzzy Association Rules (CFAR) is an effective method for rule mining which has the ability to deal with Sharp Boundary problems due to its flexibility in quantitative attribute domains and therefore it reduces the uncertainty. In this article a new hybrid method is proposed to reduce the uncertainty in decision making based on CA and CFAR. Simulation results show that the proposed method provides more understandable and has lower risk and more precise and flexibility as it reduces the generated rules. © 2013 IEEE.