Preparation of new tubular carbon ultrafiltration membrane for oily wastewater treatment by air gap membrane distillation

Abstract

The present study focuses on the preparation of a new tubular carbon ultrafiltration (UF) membrane for oily wastewater treatment by air gap membrane distillation (AGMD). The UF membrane was elaborated following a slip casting method by deposition of a thin carbon film over a previously prepared microfiltration (MF) carbon membrane. The mesoporous top layer was achieved using viscous suspension composed by commercial black carbon (BC) powder with an average particle size of 60 nm added to an alcoholic solution of novolac-phenolic resin (NPR). After curing at 150°C during 60 min and carbonization at 700°C during 300 min under nitrogen atmosphere, the resulting UF membrane exhibits an average pore diameter of about 4 nm and a thickness around 9 µm. The determination of water permeability shows a value of 18 L/h·m2·bar. In addition, a hydrophobic character has been identified which allows the application of air gap membrane distillation for oily waste water treatment. High salt and oil retention of about 99% were then achieved.