Anagrafe della ricerca

Management of drilling and produced water is becoming of greater concern, also due to stringent regulations and discharge limits being enforced worldwide. Forward osmosis (FO) is an emerging treatment process, equivalent to reverse osmosis in terms of quality of the treated water, but with key potential advantages compared to this established technology. High rejection of contaminants is combined in FO with low irreversible fouling of membranes and with the prospective to use a smaller amount of energy or energy of lesser value to drive the separation of water from contaminants. We will advance FO and we will demonstrate its effectiveness to treat produced water for beneficial reuse and to reduce the associated waste streams in the oil and gas industry. The main goals will be the identification of the best operating procedure to maximize water productivity and contaminant rejection when treating typical wastewater streams from oil and gas operations, as well as the creation of an FO membrane specifically customized for this process. Commercial thin-film composite FO membranes will be initially applied to improve process performance by studying the effect of cross-flow, draw solution concentration, and recovery rate on treated water. Different draw solutions will be evaluated, including thermolytic salts, such as carbonated trimethylamine. Membrane fouling will be studied in detail, while osmotic backwash and surface cleaning cycles will be optimized to achieve near complete recovery of the membrane performance. Simultaneously, membranes will be permanently modified using highly hydrophilic materials, via a scalable coating protocol. These membranes will have reduced fouling propensity and improved mass transport, especially when challenged by typical waste streams from oil and gas operation. Pilot runs will be conducted using both commercial and functionalized membrane modules to demonstrate the feasibility of our optimized FO process at medium scale.