SBIR-STTR Award

This Small Business Innovation Research (SBIR) Phase I project will develop boron-doped ultrananocrystalline diamond (UNCD) electrodes for electrochemical treatment/destruction of recalcitrant organics in industrial wastewater via direct anodic oxidation. Boron-doped diamond (BDD) film electrodes have generated considerable interest due to their ability to readily mineralize complex waste streams. Other treatment methods (e.g., reverse osmosis and activated carbon) simply concentrate toxins, which produces residuals requiring disposal in hazardous waste landfills or incinerators. UNCD provides many advantages over traditional diamond for electrodes (e.g., thin, low-stress, phase-pure films). UNCD films consist of phase pure, 2-5 nm grains with atomically abrupt grain boundaries. UNCD costs less than larger-grained BDD films, are resistant to grain-boundary ion transport, and exhibit lower stress. The objective of this project is to optimize the company?s existing boron-doped UNCD technology to develop low-cost, long-lifetime electrodes to enable wide-spread adoption of electrochemical wastewater treatment/destruction. The project will determine the effects of surface morphology, doping, substrate and processing methodology for UNCD electrodes to quantify costs, electrochemical performance and lifetime for wastewater treatment/destruction.The broader impact/commercial potential of this project is substantial. Thin, boron-doped UNCD films will reduce electrode resistive losses and thereby lower the overall power consumption for water treatment and other electrochemical applications of boron-doped diamond. Since water quality has a great impact on human health, enabling electrochemical water treatment through electrode lifetime improvements and reductions in power and capital costs would be both an attractive market opportunity and have a significant positive impact on healthcare and energy costs. The 2007 worldwide market for ozone, an alternative wastewater treatment technology, was $277 million and the available worldwide market for water treatment of all types in 2010 is expected to exceed $340 billion. The market for an improved electrochemical wastewater treatment/destruction technology for recalcitrant organics is expected to exceed the current size of the ozone wastewater treatment market. Leveraging a greater understanding of UNCD electrochemistry from this project would also enable alternative applications, including low-cost point-of-use or portable water or wastewater treatment, and water quality monitoring and bacterial disinfection to reduce the need for chlorine, in addition to applications in the area of MEMS-based biochemical sensors.

This Small Business Innovation Research (SBIR) Phase II project will employ the boron-doped ultrananocyrstalline diamond (BD-UNCD) electrodes developed during the Phase I project to fabricate and characterize electrochemical cells and systems for the on-site generation (OSG) of advanced oxidants (chlorine-based mixed oxidants - hydrogen peroxide combined with hypochlorite - and sodium persulfate) and apply them to targeted water treatment applications. The primary research objectives are to determine the optimal conditions to generate oxidants and to establish the projected lifetime of the electrodes. BD-UNCD cells will demonstrate higher rates of oxidant production at lower costs and with greater energy efficiency than competing electrodes due to higher current densities and over-potentials for O2 and H2 evolution at the anode and cathode. The known difficulties with existing approaches of disinfection, such as the inadequate destruction of pathogens (Cryptosporidium), ineffective operation below 10°C, generation of large quantities of O2 and H2, and electrode fouling are expected to be mitigated substantially through use of BD-UNCD electrodes. Sodium persulfate (SPS) has been used as a highly effective oxidant capable of oxidative destruction of recalcitrant organics such as in oil-contaminated sea water. BD-UNCD technology will dramatically reduce the cost and increase flexibility of OSG water treatment using SPS. The broader impact/commercial potential of this project is the development of a safer, cheaper, more environmentally friendly technology to generate "green" oxidants using diamond electrodes that can be used for a number of water treatment applications including purification, disinfection, and remediation. The market for chlorine-based disinfection systems alone is $20 billion with a correspondingly large impact on human health and national security issues associated with transporting vast quantities of hazardous materials. Overcoming technical barriers that have prevented diamond from being used for oxidant generation will require advances in the synthesis and large-scale manufacturing of diamond thin films that will impact other applications of this material. The electrochemistry of diamond is not well understood in the conditions needed for OSG. Better understanding of these reactions and the technological trade-offs between cell design and electrode geometry will impact related applications including the development of compact systems for third-world potable water generation, small scale desalination, the energy efficient electrochemical synthesis of new materials and other point-of-use applications of advanced oxidants. Large scale on-site generation of persulfates will enable highly effective treatment of refractory organics found in oil contaminated sea water and waste water associated with bitumen refining.