Ngai Yin Yip


926B S.W. Mudd
Mail Code 4711

Tel(212) 854-2905
Fax(212) 854-7081

Ngai Yin Yip and his research team are advancing technologies to address challenges at the nexus of water, energy, and the environment. The lab is currently developing new materials and methods for energy efficient desalination, investigating a novel membrane-based technique to harness low-grade heat, and exploring innovative physicochemical strategies for resource recovery from waste streams.

Research Interests

Water purification technologies, desalination, membrane-based processes, produced water treatment, hypersaline brine management, transport theory, wastewater management, resource recovery, alternative energy production, low-grade heat utilization, water-energy nexus

The production of clean water requires energy, and the generation of energy uses large quantities of water. Yip is interested in the intricate link between water and energy, and the intertwined relation with the environment. The research group focuses on advancing technologies and innovations for the sustainable production of water and energy to address challenges at the water-energy-environment nexus. A pressing problem is the purification of challenging waste streams such as produced water from oil and gas operations that is currently beyond conventional treatment methods because of the high salt and contaminant concentration. He and his team are developing new reverse osmosis and electrodialysis membrane materials for more efficient desalination of hypersaline feed streams. At the same time, the Yip lab is investigating a novel membrane-based technology that is driven by the vapor pressure of water to harness widely abundant low-temperature heat from natural and anthropogenic sources for sustainable power generation.

Huge amounts of energy are expended to capture or extract the essential nutrients of nitrogen and phosphorus for agriculture. The research team is exploring innovative physicochemical technologies to recover and reuse N and P from wastewater. The successful evolution from a once-through to closed-loop circular utilization will translate to significant energy savings in addition to preventing environmental problems such as undesired eutrophication and harmful algal blooms. Due to the multidisciplinary nature of the research, Yip works closely with a range of scientists and engineers, including chemical engineers, material scientists, microbiologists, and physicists.

Yip received his Ph.D., M.S., and M.Ph. in Chemical and Environmental Engineering from Yale University, and B.Eng. in Civil and Environmental Engineering (Minor in Business Administration) from Nanyang Technological University, Singapore.


  • Postdoctoral research fellow, SCELSE (Singapore Centre on Environmental Life Sciences Engineering), Nanyang Technological University, Singapore, 2014-2015
  • Adjunct Associate Research Scientist, Columbia University, 2014-2015


  • Assistant professor of earth and environmental engineering, Columbia University, 2015–
  • Assistant manager, National Environment Agency, Singapore, 2004-2008


  • American Chemical Society (ACS)
  • Association of Environmental Engineering and Science Professors (AEESP)
  • North American Membrane Society (NAMS)


  • CH2M Hill/AEESP Outstanding Doctoral Dissertation Award, 2015
  • Environmental Science & Technology Best Papers of 2013, Environmental Technology: Second Runner-up, 2014


  • Yip, N.Y., Brogioli, D., Hamelers, B., and Nijmeijer, K., “Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects”, Environmental Science & Technology, Volume 50, November 2016, 12072–12094.
  • Straub, A.P., Yip, N.Y., Lin, S., Lee, J., and Elimelech, M., “Harvesting low-grade heat energy using thermo-osmotic vapor transport through nanoporous membranes”, Nature Energy, June 2016, Volume 1, 16090.
  • Yip, N.Y. and Elimelech, M., “Comparison of Energy Efficiency and Power Density in Pressure Retarded Osmosis and Reverse Electrodialysis”, Environmental Science & Technology, Volume 48, September 2014, 11002–11012.
  • Shaffer, D.L., Arias Chavez, L.H., Ben-Sasson, M., Romero-Vargas Castrillón, S., Yip, N.Y., and Elimelech, M., “Desalination and Reuse of High-Salinity Shale Gas Produced Water: Drivers, Technologies, and Future Directions”, Environmental Science & Technology, September 2013, Volume 47, 9569–9583.
  • Yip, N.Y., and Elimelech, M., “Thermodynamic and Energy Efficiency Analysis of Power Generation from Natural Salinity Gradients by Pressure Retarded Osmosis”, Environmental Science & Technology, Volume 46, May 2012, 5230–5239.
  • Yip, N.Y. and Elimelech, M., “Performance Limiting Effects in Power Generation from Salinity Gradients by Pressure Retarded Osmosis”, Environmental Science & Technology, Volume 45, December 2011, 10273-10282.
  • Yip, N.Y., Tiraferri, A., Phillip, W.A., Schiffman, J.D., Laura, A.H., Kim, Y.C., and Elimelech, M., “Thin-Film Composite Pressure Retarded Osmosis Membranes for Sustainable Power Generation from Salinity Gradients”, Environmental Science & Technology, Volume 45, May 2011, 4360–4369.
  • Tiraferri, A., Yip, N.Y., Phillip, W.A., Schiffman, J.D., and Elimelech, M., “Relating Performance of Thin-Film Composite Forward Osmosis Membranes to Support Layer Formation and Structure”, Journal of Membrane Science, Volume 367, February 2011, 340-352.