Scientists at the University of Utah have developed a new concept in water treatment.
The researchers have made an electrobiochemical reactor in which a low electrical voltage is applied to microbes to help them quickly and efficiently remove pollutants from mining, industrial and agricultural wastewater.
The patented electrobiochemical reactor (EBR) process replaces tons of chemicals with a small amount of electricity that feed microbes with electrons.
Tests have shown that the electrons accelerate how quickly the microbes remove pollutants such as arsenic, selenium, mercury and other materials, significantly reducing the cost of wastewater cleanup.
Metallurgical engineer Jack Adams of the College of Mines and Earth Sciences said the new method could enhance just about any type of wastewater treatment.
It now is being tested primarily for removing metals from mining wastewater, but also could be used for other industrial and agricultural wastes, he added.
In conventional wastewater treatment, microbes or chemicals alter or remove contaminants by adding or removing electrons. The electrons come from large excesses of nutrients and chemicals added to the systems to adjust the reactor chemistry for microbial growth and contaminant removal.
Those large excesses must be added to compensate for changes in water chemistry and other factors that limit the availability of electrons to remove pollutants.
The electrobiochemical reactor or EBR system overcomes these shortcomings by directly supplying excess electrons to the reactor and microbes using low voltage and no current, unlike other systems that provide large electrical currents.
One volt supplies about one trillion trillion electrons (note: trillion twice is correct). These electrons replace the electrons normally supplied by excess nutrients and chemicals, at a considerable savings and with greater efficiency.