We are proud to announce that our Chief Executive Officer and Chief Scientist, Kevin Harvey, and his partner, Dr. Jonathan Brant at the University of Wyoming, have officially received a United States Patent for Desalination Membranes for Subsurface Irrigation.
Highly saline wastewaters are generated in industrial applications such as the exploration and production of oil and natural gas. This produced water is typically managed by injection into a deep well or evaporation ponds. Both of these approaches are disposal techniques and not considered treatment processes, nor do they provide beneficial use.
The rapid growth of the world’s population continues to place stress on our finite and limited freshwater resources. This stress has led stakeholders to seek out ways to reduce the amounts of freshwater that are used in industrial and agricultural systems. Agricultural activities are particularly targeted because they generally represent the largest consumer of freshwater in many states. For example, crop irrigation is the single largest use (39% total) of fresh water in the United States. To meet this challenge, many are turning to the reuse of “impaired” waters for irrigation of crops and vegetation. The paradigm has shifted from considering these effluent streams as “waste” to now seeing them as a valuable resource. This would require overcoming desalination processes in a way that is both cost effective and practically feasible.
Dr. Brant and Kevin envisioned a system whereby saline water would be delivered to subsurface soil in tubes like those used in drip irrigation. The difference is that the tubes would be constructed of membranes and other materials that are used in separating solids, including salts, from water. These membranes are formed of a matrix material that includes a plurality of nanoparticles which increase the flux rate of the membrane and/or increase the mechanical strength of the membrane allowing for reducing the thickness of the membrane which further increases its flux rate. Water is able to pass through the active layer of the membrane while solids/salts are prevented from passing through. The energy used to transport freshwater across the membrane and into the soil is the vapor pressure gradient between the water in the tubes and the drier soil on the outside of the tubes. The amount of nanoparticles may be varied to provide desired qualities to a resulting membrane. One application of such membranes is in a sub-surface irrigation system that utilizes saline produced water from oil and gas operations which would solve water management issues while simultaneously growing forage or food crops.