Tzahi Y. Cath

Ben L. Fryrear Professor, Civil and Environmental Engineering
Tzahi CathMy students and I conduct research in the area of water and wastewater treatment, and specifically we focus on the use of commercial and novel membrane processes. In the area of wastewater treatment and reuse we investigate the performance and enhancement of on-site wastewater treatment using novel hybrid membrane bioreactors and sequencing batch reactors. In this study we focus on the simultaneous optimization of energy consumption, chemical use, and nutrient and organic removal. We also explore the use of byproducts such as biosolids for bio-energy production. We also investigate novel membrane processes such as osmotically driven membrane processes (forward osmosis and pressure-retarded osmosis) for multi-barrier treatment of domestic and industrial wastewater for ultimate direct potable reuse. Specifically, our research focuses on investigation of solute and solvent mass transport in forward osmosis and the effects of these phenomena on future industrial implementation of the technology.

In the area of desalination, my student and I investigate novel thermally driven membrane processes such as membrane distillation and osmotic distillation. Specifically, we investigate the potential implementation of these processes in industrial settings where low grade heat and impaired water are readily available and high quality water is needed. We also investigate the utilization of the process for harvesting of minerals during desalination of brines. Also in the area of desalination we investigate novel thermally and chemically resistant nanofiltration membranes for various industrial applications. In particular, we study the occurrence, characteristics, and treatment of produced water from gas and oil exploration, and specifically coal-bed methane produced water.


Fax: 303-273-3413
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  • PhD Civil and Environmental Engineering, The University of Nevada, Reno, 2003
  • MS Civil and Environmental Engineering, The University of Nevada, Reno, 2001
  • BS. Mechanical Engineering, Tel Aviv University, 1992


  • Hancock, N.T., Xu, P., Roby, M.J., Gomez, J.D., and Cath, T.Y., Towards direct potable reuse with forward osmosis: Technical assessment of long-term process performance at the pilot scale, Journal of Membrane Science (2013) Accepted.
  • Xu, P., Tzahi Cath, T.Y., Robertson, A.P., Reinhard, M., Leckie, J.O., Drewes,J.E., Critical review of desalination concentrate management, treatment and beneficial use, Environmental Engineering Science, (2013) Accepted.
  • Coday, B., Heil, D.M., Xu, P., Cath, T.Y., The effects of transmembrane hydraulic pressure on performance of forward osmosis membranes, Environmental Science and Technology, 47 (5) (2013)2386-2393. Supporting Information.
  • Siegrist, R.L., McCray, J.E., Lowe, K.S., Cath, T.Y., Munakata-Marr, J, Onsite and decentralized Wastewater Systems: Advances from a decade of research and educational efforts, WATER,February 2013.
  • Cath, T.Y., Elimelech, M, McCutcheon, J.R., McGinnis, R.L., Achilli, A., Anastasio, D., Brady, A.R., Childress, A.E., Farr, I.V, Hancock, N.T., Lampi, J., Nghiem, L.D., Xie, M., Yip, N.Y., Standard methodology for evaluating membrane performance in osmotically driven membrane processes, Desalination 312 (2013) 31-38.
  • Hickenbottom, K.L., Hancock, N.T., Hutchings, N.R., Appleton, E.W,. Beaudry, E.G., Xu, P., Cath, T.Y., Forward osmosis treatment of drilling mud and fracturing wastewater from oil and gas operations, Desalination, 312 (2013) 60-66.
  • Hancock, N.T., Black, N., Cath, T.Y., Life cycle assessment of hybrid osmotically driven membrane processes for seawater desalination and wastewater reclamation, Water Research, 46 (4) (2012)1145–1154. Supporting Information.
  • Hancock, N.T., Phillip, W., Elimelech, M., and Cath, T.Y., Modeling bi-directional solute permeation in osmotically driven membrane processes, Environmental Science and Technology, 45 (24) (2011) 10642–10651. Supporting Information
  • Nghiem, L.D., Hildinger, F., Hai, F.I., Cath, T.Y., Treatment of saline aqueous solutions using direct contact membrane distillation, Desalination and Water Treatment, 32 (2011) 234–241.
  • Hancock, N.T., Xu, P., Heil, D.M., Bellona, C., and Cath, T.Y., A comprehensive bench- and pilot-scale investigation of trace organic compound rejection by forward osmosis, Environmental Science and Technology, 45 (19) (2011) 8483-8490. Supporting Information
  • Cath, T.Y., Drewes, J.E., Lundin, C.D., Hancock, N.T., Forward osmosis–reverse osmosis process offers a novel hybrid solution for water purification and reuse, IDA Journal on Desalination and Water Reuse, Fourth Quarter 2010, January 2011.
  • Nghiem, L.D., Cath, T.Y., A scaling mitigation approach during direct contact membrane distillation, Separation and Purification Technology, 80 (2) (2011) 315-322.
  • Cath, T.Y., Osmotically and thermally driven membrane processes for enhancement of water recovery in desalination processes, Desalination and Water Treatment, 15 (2010) 279–286.
  • Cath, T.Y, Hancock, N.T., Lundin, C.D., Hoppe-Jones, C., and Drewes, J.E., “A multi barrier hybrid osmotic dilution process for simultaneous desalination and purification of impaired water”, Journal of Membrane Science, 362 (2010) 417–426.
  • Achilli, A., Cath, T.Y., Childress, A.E., “Selection of inorganic-based draw solutions for forward osmosis applications”, Journal of Membrane Science, 364 (2010) 233–241.