Rejection of Pharmaceutically Active and Endocrine Disrupting Compounds by Low and High Pressure Membranes

Pharmaceutically Active Compounds (PhACs), Personal Care Products (PCPs) and Endocrine Disrupting Compounds (EDCs) – present in surface waters due to wastewater effluents discharged to surface waters – are of increasing concern as future removal targets in drinking water treatment plants that recycle wastewater effluents or use wastewater-contaminated surface waters. The threat of trace contaminants becomes more extensive after identification of PhACs and EDCs in many effluents of wastewater treatment plants and as well as tap drinking water of some water utilities. Although the health risks of PhACs, PCPs and EDCs polluting sources of water are partly recognized, interpretation of consequences are controversial, the future effects of altered drinking water with trace contaminants remains uncertain and presently do not constitute a problem of critical concern for human beings. Esthetical considerations of the public arise for many drinking water utilities that target as important goal high-quality drinking water. Nonetheless, disregarding the facts that those compounds continue currently unregulated, the study of their removal through water membrane treatment is presently of great scientific interest for the future, as undesirable effects are more commonly been identified in large concentrations in surface waters and as water resources become scarce and demands of recycled water will arise.

Many studies have shown that conventional water treatment has limitations in removing PhACs, PCPs and EDCs. Hence, investigations started using membrane filtration technology as barrier to trace contaminants. Particularly nanofiltration (NF) and reverse osmosis (RO) have demonstrated promising rejection results. Nonetheless, there is a lack of fundamental understanding needed to elucidate key parameters that could be used effectively for the prediction of contaminants separation that predict solute–membrane interactions and eventually rejection. Characteristics such as MWCO, porosity, membrane morphology, charge, and hydrophobicity of the membrane; interacting with compound or solute properties such as MW, molecular size, charge, and hydrophobicity as well as the feedwater chemistry must be considered when determining rejection of solutes by RO or NF membranes.

Our research will try to understand fundamental interactions occurring between compounds and membranes that influence rejection during membrane filtration. Our focus will be to demonstrate that modified properties of pre-fouled membranes when compared to clean ones, may possibly result in improved or diminished (e.g. decreased electrostatic charge) rejections of PhACs and EDCs. Finally, some models will be defined to describe or predict compound rejection based on compound properties, membrane selection, chemistry of the solution, and operating conditions.