Scientists at NASA's Glenn Research Center have developed a unique water purification method that can be used for water recycling or point-of-use applications. Originally developed as a means to recycle water in space, this technology has applications in industrial water treatment, water recycling, and water purification for military bases, disaster sites, and regions without easy access to clean water. Relying on only electrical energy, this technology uses plasma-generated reactive species to decompose organic contaminants, ranging from submicron particles to water soluble organics like glycol, ethanol, and industrial dyes.
Highly oxidizing water treatments, like ozonation and UV-ionization, have proven useful in removing organics from water, but they require high capital costs and large amounts of wasteful energy consumption. Glenn's approach to water purification uses high-voltage, nanosecond-pulsed non-equilibrium plasma to treat water. The pulsed electrical discharge destroys micro-organisms in liquid, essentially sterilizing the water, without the use of toxic chemicals or filters. The plasma creates highly reactive OH radicals (e.g. hydroperoxl, hydrogen peroxide, super oxide O2) that break down organic contaminants into carbon dioxide and water. The nano-pulses ensure that only enough energy is produced to destroy the contaminant without heating up the water, eliminating the need for cooling loops or downtime that is associated with other processes (such as UV-ionization). NASA's water purification technology relies only on electricity and can be scaled to meet a wide range of needs, from small portable units that purify drinking water in disaster relief, to million-gallons-per-day industrial applications. This technology is simple, straightforward, and low-cost, with virtually no consumables or byproducts. Furthermore, the plasma pulse technology can function as a standalone purification process, or as an add-on to existing solutions as a polishing step.
The technology provides clean water on demand; accommodates large-volume, high-throughput applications; and works with in-volume and in-line water feed systems. It operates without filters, which can often become fouled or punctured, and is housed in a self-contained unit. Applications include wastewater treatment; pharmaceutical, food, and beverage water treatment; pretreatment of contaminants; point-of-use drinking water; groundwater treatment; EPA Superfund site cleanup; and hydraulic fracturing water reuse.