A new technology, developed with NIEHS funding, will provide safe drinking water to California communities at approximately half the cost of other options and with virtually no secondary waste.
NIEHS Superfund Research Program (SRP) small business grantee Microvi Biotechnologies celebrated installation of its advanced nitrate removal technology during a grand opening Jan. 25 at Sunny Slope Water Company. The company delivers water to 30,000 households in southern California, and the new system will provide more than 200 million gallons of treated water to its customers.
"We are proud to partner with Microvi," said Ken Tcheng, general manager of Sunny Slope Water Company. "We found that Microvi’s Denitrovi technology not only provided the water quality regulators demand and our customers expect, but also solves the costly waste disposal problem of a conventional system."
Clean water without secondary waste
Sunny Slope, like many water providers in the Los Angeles Basin, needed to find a way to treat high levels of nitrate in its groundwater. The Denitrovi technology uses a biological process to convert nitrate in water into nitrogen gas.
The system produces no byproducts or sludge, and safely releases nitrogen gas into the atmosphere. The technology solves the costly waste disposal problem of conventional systems and is easy to operate.
"It’s amazing to see a biological treatment system that doesn’t produce secondary waste," said Shane Chapman, general manager of the Upper San Gabriel Valley Municipal Water District. "Waste streams have always been a huge environmental and cost issue in water treatment. This is a long-overdue course correction for the industry."
Economical source in time of scarcity
As a result of extreme droughts and water shortages, California must find new ways to supply much needed water. Groundwater supplies are one source, but the U.S. Environmental Protection Agency has estimated that around 10 percent of California’s state area has groundwater contaminated with nitrate (see sidebar). That translates to nearly 3,000 groundwater wells.
"With a small footprint, virtually no waste stream, and extreme energy efficiency, Denitrovi offers significant cost and operational advantages over any existing technology for nitrate removal," said Fatemeh Shirazi, Ph.D., Microvi chief executive officer and chief technology officer.
Origins in SRP small business grant
Initial testing for the technology began with a now-completed SRP small business grant(https://tools.niehs.nih.gov/srp/programs/Program_detail.cfm?Project_ID=R44ES011880&FY=2009) focused on removing perchlorate from contaminated water. Perchlorate is an industrial solvent, and it is often found in combination with other contaminants such as nitrate. Scientists at Microvi discovered that they could use their technology to clean up both contaminants.
"The early stages of Microvi’s perchlorate removal grant, completed in 2009, provided the scientific basis to expand their technology into unanticipated remediation applications," said NIEHS Program Officer Heather Henry, Ph.D. "The installation at Sunny Slope Water Company is a great research translation success story that links basic research to beneficial use."
Ameen Razavi, director of innovation research at Microvi, explained that the chemical pathways involved in the breakdown of perchlorate and nitrate are so similar that the Denitrovi technology degrades both. "Denitrovi has gone through rigorous consumer safety approval by the National Sanitation Foundation and the California Division of Drinking Water, and can ultimately help make billions of gallons of California groundwater drinkable again."
(Sara Mishamandani Amolegbe is a research and communication specialist for MDB Inc., a contractor for the NIEHS Division of Extramural Research and Training.)