A new approach to desalination could disrupt the water industry, and provide a sustainable way to desalinate hypersaline brines which cause water pollution.
A team from Columbia University School of Engineering and Applied Science has searched for a simple and inexpensive way to desalinate hypersaline brines for applications ranging from agricultural to industrial, and possibly for human consumption.
The need for desalination
Hypersaline brines are water containing high concentrations of dissolved salt, with saline levels higher than ocean water. Hypersaline brines are a growing environmental concern. They are costly and challenging to treat. They are caused by:
- Water produced during oil and gas production;
- Inland desalination concentrate;
- Landfill leachate (a major problem for municipal solid waste landfills), flue gas desulfurization wastewater from fossil-fuel power plants; and
- Effluent from industrial processes.
If hypersaline brines are improperly managed, they can cause the pollution of surface and groundwater resources.
The radical desalination approach
According to Columbia University, the team led by Ngai Yin Yip, assistant professor of earth and environmental engineering, have found a radical desalination approach for hypersaline brines. It is called “temperature swing solvent extraction (TSSE).”
Yip said: “I thought solvent extraction could be a good alternative desalination approach that is radically different from conventional methods because it is membrane-less and not based on evaporative phase-change.Our results show that TSSE could be a disruptive technology- it’s effective, efficient, scalable, and can be sustainably powered.”
Yip concluded: “We think TSSE will be transformational for the water industry,” he adds. “It can displace the prevailing practice of costly distillation for desalination of high-salinity brines and tackle higher salinities that RO cannot handle. This will radically improve the sustainability in the treatment of produced water, inland desalination concentrate, landfill leachate, and other hypersaline streams of emerging importance. We can eliminate the pollution problems from these brines and create cleaner, more useable water for our planet.”