Desalination 222 (2008) 410–418
Presented at the conference on Desalination and the Environment. Sponsored by the European Desalination Society
and Center for Research and Technology Hellas (CERTH), Sani Resort, Halkidiki, Greece, April 22–25, 2007.
Modeling of volatile organic compounds removal from
water by pervaporation process
A.A. Ghoreyshi*, M. Jahanshahi, K. Peyvandi
Department of Chemical Engineering, School of Engineering, University of Mazandaran,
P.O. Box 484, Babol, Iran
Tel. +111 3234201; Fax +111 3234501; email: aa_ghoreyshi@yahoo.com
Received 24 December 2006; accepted 3 January 2007
Abstract
Pervaporation is a membrane technology utilizing a dense non-porous homogeneous polymeric film as a
selective separation barrier. In recent years, pervaporation using dense membranes has emerged as a promising
remediation method for trace organic removal from dilute aqueous solutions. The mathematical model commonly
used to determine liquid and polymer phase resistances is the resistance-in-series model. In most studies the
concentration or pressure gradient is considered as the driving force. In the present study a model was developed
based on resistance-in-series model considering the chemical potential gradient as the true driving force in which
the total resistance to mass transfer is defined as the sum of the liquid, membrane and vapor resistance. The model was
validated by the experimental data available in the literature for various organic solutions and different membranes
including PDMS and composite membranes. The results obtained show that the liquid phase boundary layer plays
a significant rule in overall mass transport for all cases under study and ignoring this contribution could lead to a
significant error in design and scale-up applications. It was also shown that the flux of permeating component is
unaffected by the downstream pressure at low pressures up to 10 mmHg which indicates that for such systems the
operating condition can be economically designed based on a moderate vacuum at downstream side instead of
using a full expensive vacuum system.
Keywords: VOCs; Membrane; Pervaporation; Mass transfer; PDMS
1. Introduction
Water is a vital substance for human and other
living creatures. Shortage of water in major parts
of the world makes necessary the investigation on
water treatment and recycling systems. Volatile
organic compounds (VOCs) are a category of
important contaminants for drinking water sources
and industrial wastewater. Presence of these sub-
stances in a certain amount in water can jeopardize
the life of living creatures. At present, different
processes such as biological treatment, adsorption *Corresponding author.
0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V.
doi:10.1016/j.desal.2007.01.174