Περίληψη | Laboratory experiments were conducted to characterize and quantify the capacity and kinetics of the combined effects of natural attenuation processes, such as adsorption, reduction, and precipitation, for hexavalent chromium [Cr(VI)] in a variable geochemical (i.e. fraction of organic carbon [foc], redox) environment of glaciated soils. Equilibrium attenuation terms: linear sorption (Kd), estimated capacity, and non-linear Langmuir (KL, Q) sorption parameters; varied over several orders of magnitude. The pseudo-first-order rate of disappearance of Cr(VI) from aqueous:soil slurries ranged from ∼10−5 to ∼10−1/min. An operationally defined kinetic attenuation term, attenuation capacity (AC), describing the quantity of Cr(VI) disappearing from the slurries, ranged from 1.1 to ∼12 μg Cr(VI)/g soil/7 days. The linear Kd's and estimated attenuation capacities were indirectly and directly related to increasing soil pH and foc, respectively. The AC values decreased and increased as a function of increasing soil pH and foc, respectively. The parameters determined in this work were used to evaluate the kinetics, capacity, and stability of chromium attenuation in the sub-wetland saturated soils in Hellerich (2004. A field, laboratory, and modeling study of natural attenuation processes affecting the fate and transport of hexavalent chromium in a redox variable groundwater environment. Ph.D. Dissertation, Department of Civil and Environmental Engineering, University of Connecticut-Storrs) using a statistical simulation framework | en |
Βιβλιογραφική Αναφορά | Hellerich L.A., and N.P. Nikolaidis, "Studies of Hexavalent Chromium Attenuation in Redox Variable Soils Obtained From a Sandy to Sub-Wetland Groundwater Environment", Vol. 39, no. 13, pp. 2851–2868, Aug. 2005. doi:10.1016/j.watres.2005.05.003 | en |