Editor-in-Chief Elisabeth Lisican showcases a handful of features to read in the April 2017 issue of Water & Wastes Digest.
New purification method using forward osmosis can potentially reduce desalination energy cost by 70% and enable wider commercial use
QuantumSphere, Inc., developer of advanced catalyst materials, high-performance electrode systems and related process chemistries for portable power and clean-tech applications, has filed for a U.S. patent on a water purification process that serves as a more energy-efficient alternative to desalination methods now commonly used to help meet growing water needs around the world.
QuantumSphere intends to commercialize the forward osmosis technology to address the challenge of growing demand for potable water. According to Lux Research, the world’s water needs are expected to grow 40% by 2030, and today’s stressed water resources and systems are unsustainable. Water cultivation systems are expected to see market growth from $522 billion in 2007 to nearly $1 trillion in 2020.
The forward osmosis process developed by QuantumSphere uses certain organic solutions to separate water from salt water or polluted water in an osmotic purification process. The company has constructed a prototype system that can purify several gallons of water a day for demonstration purposes and intends to scale the process with large development partners to serve large-scale municipal drinking supplies.
The QuantumSphere process will provide an alternative to thermal desalination and reverse osmosis desalination processes that require more energy than the forward osmosis process it has developed.
“Today, most high-volume thermal desalination is conducted at complex plants in the Middle East, where an inexpensive oil supply makes it more practical than most other parts of the world,” said Subra Iyer, principal technologist for QuantumSphere. “The reverse osmosis process also requires tremendous amounts of energy for desalination. The forward osmosis process we’ve developed can purify water at less than 3,000 kWh per acre ft, which is approximately 70% cheaper than the energy cost of traditional reverse osmosis processes. QuantumSphere has developed a prototype that is scalable and can eventually be used to supply fresh drinking water to large populations located near virtually any water source. The company is seeking development partners to further refine and scale the process to make it a commercially viable large-scale process for seawater desalination.”
Forward osmosis using QuantumSphere’s proprietary process can also purify brackish and polluted water. The process uses a semi-permeable membrane to separate water from salt water into a special organic solution across the membrane. The diluted organic solution is then warmed to cause the specially formulated organic solute to drop out, leaving only fresh drinking water after a final purification step through activated charcoal.