Volatile Organic Compound (VOC) Transport through a Composite Liner with Co-Extruded Geomembrane Containing Ethylene Vinyl-Alcohol (EVOH)

摘要

A co-extruded geomembrane (GM) with a layer of ethylene vinyl-alcohol (EVOH) is being introduced in environmental containment applications to take advantage of the hydrophobic properties of polyethylene as a barrier to contaminant flux; specifically, the potential to substantially reduce the diffusion of non-polar volatile organic compounds (VOCs). This research evaluates and compares the relative transport of common VOCs through composite landfill liners constructed with a co-extruded GM that contains EVOH. Based on experimental results from diffusion tests with composite liners, high-density polyethylene (HDPE) GM produces more rapid breakthrough and higher VOC migration. A co-extruded EVOH GM had measured diffusion coefficients that were more than 20 times smaller compared to HDPE GM. The diffusion coefficients of 1.5-mm co-extruded EVOH GM were 0.53 × 10~(-13) m~2/s for methylene chloride, 0.17 × 10~(-13) m~2/s for trichloroetheylene, and 0.14 × 10~(-13) m~2/s for toluene. Based on diffusion testing, co-extruded EVOH GM acts as an effective barrier to VOC migration in composite liners.