Development of a Scalable, Low-Cost, Ultrananocrystalline Diamond Electrochemical Process for the Destruction of Contaminants of Emerging Concern (CECs)

This Small Business Innovation Research (SBIR) project will develop and ready for commercialization a scalable, low-cost process for purification of water containing Contaminants of Emerging Concern (CECs) using anodic oxidation with boron-doped ultrananocrystalline diamond (UNCD®) thin films. Resent research demonstrated that there is considerable potential for the development of electrochemical methods to remove contaminants from potable water. Most current treatment methods, such as adsorption on granular activated carbon, ion exchange, or reverse osmosis, merely transfer or concentrate the contaminants form water to another medium thus producing a concentrated waste residual that requires further treatment or disposal. Disposal often involves interment in hazardous waste landfills, incineration, or deep well injection. Additionally, recent studies have shown that CECs are present in drinking water sources and are not adequately removed using existing water treatment methods. These trace contaminants include hormones, alkylphenols, BPA, endocrine disrupting compounds and pharmaceutical and personal care products. UNDC films are phase pure diamond consisting of 2-4 nm diamond grains with atomically abrupt grain boundaries. Compared to traditional diamond films, UNCD can be deposited more rapidly in thinner, more uniform, low pin-hole density layers that are highly resistant to grain boundary ion transport, and have lower residual stresses than traditional diamond films. There attributes substantially lower the cost of UNCD compared to traditional diamond materials and greatly improve the yield and lifetime of electrodes fabricated with UNCD. These electrode reliability improvement have been demonstrated during a recent NSF SBIR awarded to Advanced Diamond Technologies. The goal of this EPA project is to develop and test low-cost anodic oxidation techniques using large area UNCD electrodes on estrogen and its chemical analogs. Estrogen itself is an important endocrine disruptor found in drinking water, however the goal of this project is to use this example to demonstrate the applicability of UNCD electrochemical oxidation techniques to high revenue applications such as the destruction of pharmaceutical drug residues and CECs in drinking water. As a gauge of the market size, the 2009 US market for non-chemical water treatments was >$4.0 billion. The 2007 worldwide market for an alternative but roughly analogous but more expensive water treatment technology (ozonolysis) was $277 million. The potential market for an improved low-cost water purification technology is therefore expected to be greater than the current ozonolysis market, especially considering the likelihood that (unlike ozonolysis) UNCD electrochemical water treatment can be applied to the home/municipal/small business markets.