Aclarity’s technology addresses water quality concerns to purify various types of water. This water purification process utilizes electricity, known as an electrochemical advanced oxidation process (EAOP). Oxidants and disinfectants are produced on the anode surface which destroy pathogens and other unwanted contaminants. Compounds such as nitrates and metal ions are reduced on the cathode surface. These redox species are formed and transform unwanted compounds to less harmful products, which allows EAOPs to operate without added chemicals. Aclarity uses the EAOP to treat water with complex water chemistry by neutralizing pH and removing unwanted contaminants. Because the electrodes are regenerative and filters are not required, maintenance needs and costs are substantially reduced. The final device can be automated by on-line water quality sensors for instantaneous and hands-off water treatment.
Aclarity’s water treatment technology addresses the inadequacies of conventional systems with the production of direct oxidants, advanced oxidants, and indirect secondary oxidants which all treat different contaminants. During water treatment with the electrochemical device, water is oxidized to form secondary reactive species such as hydroxyl radicals and ozone. The oxidants react quickly with most organic matter in water forming carbon dioxide and less harmful byproducts. In addition, direct destruction of contaminants occurs when electrons are transferred from the contaminant to the anode. Electrons oxidize other constituents in water that hydroxyl radicals and others may not (e.g. perfluorinated compounds like PFOA and PFOS)¹. Free chlorine may also form during this process from chloride in the water. In addition to powerful oxidation and disinfection capabilities, the cathode produces reductants that reduce unwanted constituents. The combination of advanced oxidant formation, indirect secondary oxidation, direct electron transfer and reduction processes shows high potential for a transformative treatment technology for varying influent water quality.
Extreme changes in pH occur on the electrode surfaces causing the pH of water to neutralize. H+ is formed on the anode and OH- is formed on the cathode, both at high quantities. The formation of these species is so high that, coupled with the unparalleled redox potentials, pathogens including bacteria, viruses, and protozoa cannot survive. These pathogens are inactivated and the pH streams are mixed neutralizing the water for safe drinking.
[¹] Zaky Chaplin (2013). Porous Substoichiometric TiO2 Anodes as Reactive Electrochemical Membranes for Water Treatment. Environ. Sci. Technol. 6554−6563.