New Membrane Platforms Beyond RO and NF: What’s on the Horizon? Availability of clean and potable water is no longer an easy thing in this century given the fact that most of the world has been experiencing this challenge. This challenge is increasing rapidly, especially in developed countries like America. About 40% of America’s water supply comes from underground water reserves. But a big problem is that a large part of this underground water is “Brackish Groundwater”, that is, water that contains high amounts of salt, calcium, magnesium and other minerals. For this reason, this water is not directly usable for drinking, irrigation or industrial use.
According to the US Geological Survey, the amount of brackish groundwater present in America is 800 times more than the fresh water pumped from all sources every year. Imagine, if this water is made useful, then the country’s water shortage can be overcome to a great extent.
New technology will change the future of water
A California-based company named Active Membranes has developed a new technology, which can prove to be revolutionary in this direction. This technology equips the membrane used in the traditional reverse osmosis (RO) desalination process with electrical conductivity.
This technology was developed at UC Riverside and UCLA and later Active Membranes licensed it and started bringing it to the market. This project has received funding from the National Alliance for Water Innovation (NAWI), a public-private partnership run by Lawrence Berkeley National Laboratory of the US Department of Energy. NAWI’s aim is to make the use of unconventional water sources possible in real life in addition to traditional water sources.
Brackish water and dirty water from the oil-gas industry will also be cleaned
According to NAWI Executive Director Peter Fisk, this new “active membrane” can also clean the dirty water (Produced Water) that comes to the surface during the process of extracting oil and gas.
Often, more dirty water comes out of oil wells than the amount of oil that comes out. It contains salt, soil particles, hydrocarbons and many other impurities, which quickly spoil the traditional RO membrane. If this dirty water is cleaned properly, it can be used for irrigation for agriculture. This will not only reduce water wastage, but it is also possible to increase oil and gas production, because currently disposing of this dirty water is a big challenge.
The biggest problems in reverse osmosis
Reverse osmosis (RO) is a widely used method of removing dissolved salts and other impurities from water. It uses very thin membranes through which water passes under pressure and salt and other particles are left behind.
- But there is a big problem with this—scaling and fouling.
- Scaling occurs when salt present in water gets deposited on the membrane surface.
- In fouling, the organic matter, soil or other particles attach to the membrane.
- With these issues, membranes require cleaning regularly, and this drives up costs that bring about the low yield of volumes of water.
Unique solution of Active Membranes
Active Membranes has found a new way to deal with this problem. They have coated the surface of the RO membrane with an extremely thin electrically conductive coating. When a low voltage charge is given to this layer, salt ions and other charged particles present in the water move away from the membrane surface.
This significantly reduces the problem of scaling and fouling. In a recent pilot test conducted in Ventura County, California, these “active” membranes produced 20-30% more water than conventional membranes.
A big step towards tackling the water crisis
- This technology can prove to be a boon not only for the US, but for many countries of the world.
- Water for agriculture: Salty or brackish water can be cleaned and used in agriculture.
- Industrial use: Many factories and industries have a huge demand for water, which can be met with this technology.
- Reuse of oil-gas industry: “Produced Water” can be used in irrigation or industrial processes instead of throwing it away.
- Urban water supply: Clean water can also be provided for drinking and domestic use in big cities.
Challenges ahead
Although this technology is extremely promising, there are some challenges in implementing it on a large scale:
- Cost: The cost of initial investment and equipment installation can be high.
- Energy consumption: Although low voltage is used, electricity will still be required.
- Maintenance: Long-term functionality of the membranes is important to maintain.
Conclusion
Water scarcity is becoming a serious challenge in the world. If the huge brackish water reserves in the US are properly cleaned and used, the water needs of millions of people can be met. This technology of Active Membranes increases water production by reducing problems like scaling and fouling.
