Volatile Organic Compounds Volatilization from Multicomponent Organic Liquids and Diffusion in Unsaturated Porous Media

2003 ◽  
Vol 2 (4) ◽  
pp. 692
Author(s):  
Guohui Wang ◽  
Sayonara Brederode F. Reckhorn ◽  
Peter Grathwohl
Keyword(s):  
Porous Media ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Organic Liquids ◽  
Unsaturated Porous Media ◽  
Volatile Organic ◽  
And Diffusion

Investigation of a decommissioned landfill barrier system containing polychlorinated biphenyl (PCB) waste after 25 years in service

2020 ◽  
Vol 57 (6) ◽  
pp. 882-902 ◽  
Author(s):  
R.S. McWatters ◽  
D.D. Jones ◽  
R.K. Rowe ◽  
J.M. Markle
Keyword(s):  
Diffusion Coefficient ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Polychlorinated Biphenyl ◽  
Compacted Clay ◽  
Partitioning Coefficient ◽  
Compacted Clay Liner ◽  
Volatile Organic ◽  
Primary Base ◽  
And Diffusion

The excavation and analysis of the barrier systems for four engineered containment cells, constructed from 1984 to 1987, is described. Very limited polychlorinated biphenyl (PCB) migration was observed over the 22–25 year period prior to decommissioning. PCBs were predominantly, and preferentially, retarded by the geotextiles (GTXs) and, where present, geomembranes (GMBs). The migration of PCBs in the primary compacted clay liner (CCL) during this period was limited both when used alone and with a GMB. The exhumed GMBs, from both cover and base barriers, had diffusive properties (with respect to volatile organic compounds) comparable to unaged GMBs. For cells with a CCL as the primary base barrier, the inferred PCB diffusion coefficient, De, was 1–2 × 10−10 m2/s and distribution coefficient, Kd, was 10–15 mL/g. For cells where a GMB was the primary base barrier, the inferred PCB partitioning coefficient, Sgf, was 150 000 and diffusion coefficient, Dg, was 1 × 10−14 m2/s. Modelling beyond the 25 years in service predicts no unacceptable PCB impact of the landfill on groundwater and indicates that the design of the barrier system was adequate for an indefinite period given the low service temperatures to which it was subjected. In this diffusion-governed system, small changes to the diffusive properties were found to have a large impact on migration.

Sign in / Sign up

Export Citation Format

Share Document