Novel Surface Grafted Membrane for Advanced Purification of Wastewaters

The declining water flux over time due to fouling represents the main onstream issue of the existent membranes in wastewater treatment. Thus, preventing and mitigating membrane fouling is considered the key challenge to improving performance and extending the use of membranes in water treatment and recovery applications. Novel membranes with improved properties will lead to reduced energy consumption, reduced cleaning and consumption of chemicals, as well as the less frequent replacement of membranes. This will decrease the cost of the filtering system, making possible their installation and adaptation according to the customer’s needs. In the the current investigation we develop methods for antfiouling and anti-scaling functionalizing of commercial ultrafiltration (UF) and microfiltration (MF) membranes form Alfa Laval and Microdyn-Nadir. The manufacturing technology aims to obtain membranes for wastewater treatment installations with improved water flux, stability, antifouling and antibacterial properties exceeding the performance of current commercial membranes. The membranes are planned to be tested by the two industrial partners for cleaning intake water to fish farms and for plant extraction process in pharma. We aim to develop a flexible platform for membrane surface modifications that can be easily scalable and applied for membranes in various water treatment applications. antifouling and anti-scaling properties are relevant. We aim for easily scalable methods for large production, such as direct surface modification inside existent commercial membrane modules. The fabrication process consists of UV grafting of polymer chains from acrylate type of monomers (acrylic acid, methacrylic acid, hydroxyethyl methacrylate) onto the surface of microfiltration membranes (PVDF and PES). The succesfull membrane hydrophilization was characterized by FTIR, wettability (contact angle measurements) and water permeability properties. The membranes shows a decrease in the contact angle from 85 to 70 for PVDF and from 61 to 44 for PES indicating hydrophilization of the membrane which was confirmed by FTIR as well. The clean water flux was measured in cross-flow configuration at room temeperature, various water flow rates and two applied pressures. The water flux was reduced due to the surface grafting but the membrane bulk prorosity was little affected by grafting. We investigated various fabrication strategies to prevent and reduce the clogging of the membranes pores during grafting. The porosity of the membrane prior an post grafting was investigated using mercury intrusion porsimetry. Acknowledgements: We would like to acknowledge funding from the MANUNET/ ERA-NET program MNET20/ENER3733.