Testing of three different PVDF membranes in membrane assisted-crystallization process: Influence of membrane structural-properties on process performance

Throughout the world an intensified use of desalination for reducing current and future water scarcity is observed. Despite the enormous benefits of desalination processes, improvements are still required in terms of lower desalted water cost, higher productivity, better water quality and enhanced eco-sustainability of the desalination process. Environmentally sensitive concentrate management is today recognized as a significant hurdle to extensive implementation of desalination technologies. Membrane assisted crystallization (MCr) offers a suitable solution for redesigning desalination process through the treatment of brine streams for the production of salts and water. In this work, three different Hyflon/polyvinylidene fluoride (PVDF) composite membranes were tested in MCr operations. The coating of PVDF membranes with Hyflon allowed increasing membrane surface hydrophobicity. The latter is the membrane essential characteristic when MCr is implemented according direct contact membrane distillation configuration like in the present work. The aim was to analyze the MCr performance in terms of membrane chemical-physical properties and process operating conditions.