Catalyx develops two-way osmosis to purify wastewater

Anaheim, Calif.-based cleantech incubator Catalyx said today it developed a technology to purify heavily polluted wastewater from the textile and other industries using a low-cost, chemical-free process.

CEO and founder Juzer Jangbarwala said the technology will be commercialized through Catalyx's fourth spinoff. The incubator is mostly self financed, with some backing from angel investors.

Jangbarwala told the Cleantech Group that droughts in areas such as Georgia are putting pressure on lawmakers to force water-intensive industries to cut back on their footprint by using less water and purifying wastewater, sometimes for the first time.

"It's less expensive than what will be required, and it can be cheaper than buying clean water," he said.

The technology uses 25-micron-thick, 85-percent porous, self-supporting, high-flux membranes with a semipermeable coating. 

The process begins with forward desalination, in which a roughly 10-percent sodium chloride solution is separated from heavily polluted water by a the semiporous membrane. The salty solution draws pure water across the membrane, leaving behind concentrated pollutants. The pure water dilutes the sodium chloride to a mixture similar to seawater, which is then desalinated using reverse osmosis technology. That water can be re-used in the industrial process, creating a closed-loop system, Jangbarwala said.

The process saves between 50 percent and 70 percent of the typical cost to dispose of wastewater, Jangbarwala said. The key to the cost savings is that the process—unlike traditional wastewater treatment—doesn't require pretreatment with pricey chemicals. Additionally, the membrane isn't fouled by pollutants because it interacts with pure water, extending its usefulness.

Jangbarwala said the concentrated pollutants are cheaper to dispose of because the volume is smaller. Alternately, the concentrated pollutants can be used as feedstock for a biogas plant to produce energy, he said.

"We're not breaking treatment technological barriers," Jangbarwala said. "Our point is that we can make the process a profit center for the textile mill."

The technology also has applications in industries that produce water polluted with organic waste, such as vegetable processing, bakeries, animal processing or sewage treatment. The wastewater is too diluted to be a viable feedstock for biogas plants, but the Catalyx system could be used to concentrate the organic matter until the biogas plant could be economically viable, he said.

Another potential use could be at offshore windmills, Jangbarwala said. The turbines can sometimes produce more energy than the grid can accept, so excess energy can be used to desalinate the surrounding seawater using the energy intensive reverse osmosis process. When the turbines are not generating energy, the forward osmosis process can be used to help seawater in a container draw in the purified water, increasing volume and creating more pressure, which can then generate energy through turbines, Jangbarwala said. The company is seeking partners to develop that technology.

Catalyx operates with the mission that clean water and energy generation is best distributed instead of centralized. Jangbarwala said the company then focuses on making thise technologies highly efficient and low cost.

Other spinoffs from Catalyx include Catalyx Nanotech, which is working with California consulting firm Dudek to develop production facilities at Southern California landfills to make high-grade graphite and hydrogen with no byproducts.

The two-way desalination technology will likely be spun out when Catalyx can secure financing to expand its market reach. The technology is being used at a pilot plant and in Pakistan. Jangbarwala said he's in talks with two large carpet manufacturers about testing the two-way desalination and expects to install one in the next four months.

Catalyx manufactures the proprietary membrane but contracts with an outside manufacturer for the off-the-shelf osmosis technology. Including the spinoffs, the company has 25 employees.