In the present study, polydimethylsiloxane (PDMS) composite membranes were used to study the removal of styrene from dilute aqueous streams by pervaporation. The influences of styrene feed concentration, permeate pressure, operating temperature, feed flow rate and membrane thickness on the pervaporation performance were investigated. The results showed that with the increase in concentration of styrene in the feed solution, both the permeation flux and the styrene enrichment factor increase. Additionally, with a decrease in thickness of the membrane, the permeation flux was observed to enhance but the enrichment factor decreased. It was also indicated that increasing in the permeate pressure, reduces driving force for mass transfer and consequently the pervaporation performance dropped. Finally, the activation energy for pervaporation of both styrene and water calculated from Arrhenius plot indicated that the permeation of water through the membrane is higher temperature dependant than styrene. (C) 2011 Elsevier B.V. All rights reserved.