Permeation of Volatile Organic Compounds through EVOH Thin Film Membranes and Coextruded LLDPE/EVOH/LLDPE Geomembranes

Abstract

Abstract Coextruded geomembranes with an inner ethylene vinyl alcohol (EVOH) layer are gaining attention as potential improved barriers to volatile organic compounds (VOCs) when used in barrier systems that would traditionally use high-density polyethylene (HDPE) geomembranes. The permeation characteristics of nine common VOCs in aqueous solutions through the EVOH layer are investigated for two thin films: a 0.015-mm-thick, 32 mol% EVOH and a 0.02-mm-thick, 44 mol% EVOH. The VOCs included aromatic hydrocarbons [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and chlorinated hydrocarbons [1,2-dichloroethane (1,2-DCA), dichloromethane (DCM), trichloroethylene (TCE), and tetrachloroethylene (PCE)]. The BTEX permeation coefficients, P g , range from 1.4 × 10 − 14 to 25 × 10 − 14 m 2 ⋅ s − 1 depending on the contaminant and mol% EVOH. When a 0.02-mm-thick, 38 mol% EVOH thin film layer is coextruded with linear low-density polyethylene (LLDPE) to form a 0.53-mm-thick geomembrane, the BTEX permeation v...