Events Calendar

Astani CEE Seminar

Speaker: Amy E. Childress, Civil and Environmental Department Chair, University of Nevada, Reno

Talk Title: Towards water and energy sustainability with innovative membrane processes and systems

Abstract: Fresh water scarcity is forcing water providers to rely on alternative water supply sources such as saline waters (e.g., seawater) and “waste” waters. Low-energy treatment processes are desired to remove both established and emerging contaminants from these process waters. Forward osmosis (FO) and membrane distillation (MD) have gained national and international attention as viable, economic alternatives for seawater desalination and wastewater reclamation. Pressure-retarded osmosis (PRO) in combination with RO is also being considered to achieve water desalination at low energy expenditure.

FO is an osmotically driven membrane separation process that can be used as a high-level pretreatment for RO or other desalination process. The FO membrane provides an economical means to pretreat process waters and protect the RO membrane from excessive fouling. The FO-followed-by-RO scheme also represents a dual osmotic barrier that may be particularly useful for the removal of micropollutants. MD is a thermally driven membrane separation process that has long been investigated in small-scale laboratory studies and has the potential to become a viable tool for water desalination and brine concentration. Compared to conventional distillation methods, MD requires only small temperature differences – temperature differences achievable through the use of low-grade or waste heat sources. Compared to RO, the driving force in MD is not reduced by osmotic pressure and thus, MD can be used to treat high salinity solutions or to provide enhanced recovery through brine desalination. Results from investigations on the energy, recovery, and water quality advantages of FO and MD over conventional methods will be presented. The state-of-the-art of research and development of FO and MD systems will also be discussed.

In PRO, water from a low salinity solution permeates through a membrane into a pressurized, high salinity solution; power is obtained by depressurizing the permeate through a hydroturbine. A synergistic RO-PRO desalination system was designed to reduce RO energy requirements and to dilute the brine generated by the RO process prior to disposal. The development and testing of this system will be presented.

Location: Kaprielian Hall (KAP) - 209

Audiences: Everyone Is Invited

Contact: Evangeline Reyes