In designing and constructing new desalination plants, creating and testing pilot facilities is one of the most expensive and time-consuming steps. Traditionally, small yet very expensive stationary pilot plants are constructed to determine the feasibility of using available water as a source for a large-scale desalination plant. The M3 system helps cut both costs and time.
"Our M3 water desalination system provides an all-in-one mobile testing plant that can be used to test almost any water source," said Alex Bartman, a graduate student on the M3 team who helped to design the sensor networks and data acquisition computer hardware in the system. "The advantages of this type of system are that it can cut costs, and because it is mobile, only one M3 system needs to be built to test multiple sources. Also, it will give an extensive amount of information that can be used to design the larger-scale desalination plant."
The M3 demonstrated its effectiveness in a recent field study in the San Joaquin Valley in which it desalted agricultural drainage water that was nearly saturated with calcium sulfate salts, accomplishing this with just one reverse osmosis (RO) stage.
"In this specific field study by our team, in the first part of the reverse osmosis process, 65 percent of the water that was fed in was recovered as drinking water, or potable water," said Yoram Cohen, professor of chemical and biomolecular engineering and lead investigator on the team. "We can potentially go up to 95 percent recovery using an accelerated chemical demineralization process that was also developed here at UCLA. This first field study with the M3 was a major achievement and the first phase of our high-recovery RO process demonstration program."
In addition to its use as a pilot-scale testing unit, the M3, according to Bartman, could also be deployed to various locations and used to produce fresh water in emergency situations.
"The M3's 'smart' nature means it can autonomously adapt to almost any variation in source water, allowing the M3 system to operate in situations where traditional RO desalination systems would fail almost immediately," he said.
Though the system is compact enough to be transported anywhere in the back of a van, it can generate 6,000 gallons of drinking water per day from the sea or 8,000 to 9,000 gallons per day from brackish groundwater. By Cohen's estimate, that means producing enough drinking water daily for up to 6,000 to 12,000 people.
Rahardianto said that the highly saline agricultural drainage wastewater in the San Joaquin Valley is one of the most difficult source waters to desalt.