DESORPTION BEHAVIOR OF TRICHLOROETHENE AND TETRACHLOROETHENE IN U.S. DEPARTMENT OF ENERGY SAVANNAH RIVER SITE UNCONFINED AQUIFER SEDIMENTS

Vangelas, K ; Robert G. Riley, R ; James E. Szecsody, J ; A. V. Mitroshkov, A ; C. F. Brown, C ; Brian02 Looney, B

Savannah River Site (S.C.)

关键词: Desorption;    Solutes;    Standard Model;    Sediments;    Soils;   

DOI  :  10.2172/899958
RP-ID  :  WSRC-STI-2006-00339
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  899958

美国|英语

来源: UNT Digital Library

【 摘 要 】

Sorption is governed by the physico-chemical processes that partition solutes between the aqueous and solid phases in aquifers. For environmental systems, a linear equilibrium relationship between the amount of contaminant in the alternative phases is often assumed. In this traditional approach, the distribution coefficient, or K{sub d}, is a ratio of contaminant associated with the solid phase to the contaminant in the water phase. Recent scientific literature has documented time-dependant behaviors in which more contaminant mass is held in the solid phase than predicted by the standard model. Depending on the specific conceptualization, this has been referred to as nonlinear sorption, time-variable sorption, or ''irreversible sorption''. The potential impact of time-variable sorption may be beneficial or detrimental depending on the specific conditions and remediation goals. Researchers at the Pacific Northwest National Laboratory (PNNL) have been studying this process to evaluate how various soil types will affect this process for sites contaminated with chlorinated solvents. The results described in this report evaluate sorption-desorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) in Savannah River Site (SRS) soils. The results of this study will be combined with ongoing PNNL research to provide a more comprehensive look at this process and its impact on contaminant plume stability and sustainability. Importantly, while the results of the study documented differences in sorption properties between two tested SRS soils, the data indicated that ''irreversible sorption'' is not influencing the sorption-desorption behaviors of TCE and PCE for these soils.