Estimation of Permeability for Organic Compounds through PVC Pipes

Abstract

A pipe-bottle model with a volume of 125 mL was proposed to estimate the permeability of benzene and toluene for the polyvinyl chloride (PVC) water pipes. The concentrations of permeant in pipe-water were directly sampled using the solid phase microextraction (SPME) technique. The permeability coefficients of benzene and toluene were 0.07 and 0.025 μg/cm/hr, respectively, indicating toluene is less permeable through the PVC pipe. Using a transient mass diffusion equation and appropriate initial and boundary conditions, the simulation studies of the concentration profiles of benzene in pipe-water implied that swelling of the PVC pipe wall might have a significant effect on the permeation experiments. The new pipe-bottle model is a less time-consuming and more sensitive means to determine the chemical resistance of polymeric pipes to permeation by organic solvents.