Grantee Research Project Results

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

EPA Contract Number: EPD12039
Title: Development of a Scalable, Low-cost, Ultrananocrystalline Diamond Electrochemical Process for the Destruction of Contaminants of Emerging Concern (CECs)
Investigators: Arumugam, Prabhu
Small Business: Advanced Diamond Technologies Inc.
EPA Contact: Richards, April
Phase: II
Project Period: June 1, 2012 through May 31, 2014
Project Amount: $299,686
RFA: Small Business Innovation Research (SBIR) - Phase II (2012) Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Drinking Water and Water Monitoring

Description:

This Small Business Innovation Research (SBIR) Phase II project will employ the large scale; highly reliable boron-doped ultrananocrystalline diamond (BD-UNCD®) electrodes developed during Phase I project to build and test Electrochemical Anodic Oxidation process (EAOP) cells and systems that can destroy Contaminants of Emerging Concern more economically and effectively than competing AOPs. BD-UNCD cells are likely to demonstrate higher rates of organic contaminant destruction at lower costs and with greater energy efficiency than competing electrodes due to higher current densities allowing smaller electrode sizes and higher rates of hydroxyl-radical generation. The known difficulties with existing EAOP electrodes (e.g. DSA) such as an inadequate rate of destruction of refractory molecules, unreliable operation below 10°C, generation of large quantities of 0₂ and H₂, which worsen current efficiency and present safety concerns, electrode fouling, limited electrode lifetime and an inability to be reverse-polarized are addressed using BD-UNCD electrodes as was demonstrated in the Phase I. The powerful combination of hydroxyl radicals, H₂0₂ and other strong oxidants fanned at the BD-UNCD anode is capable of oxidative destruction of even refractory organics such as trichloroethylene. BD-UNCD EAOP typically reduces the cost by at least an order of magnitude compared to competing AOPs.

The non-chemical water treatment market in the USA for 2009 was greater than $4 billion. Much of this market is addressed by ozonolysis, which is at least an order of magnitude more expensive and less effective for refractory organics. The potential market for a lower-cost water purification technology capable of destruction of refractory organics is therefore expected to exceed the current ozonolysis market Current methods are problematic for many reasons including, poor mineralization; formation of persistent by-products; usually limited to lower concentration wastes; they also require the addition, and subsequent removal, of chemicals such as H₂0₂ or Ozone; require pH adjustments, safety hazards associated with transporting chemical and energy inefficiency with high carbon footprints. Overcoming these technical barriers will require advances in the Synthesis and large-scale manufacturing of diamond thin films (completed in phase II) and their application and tuning to the target wastewaters with the highest economic and environmental impact. The electrochemistry of diamond requires investigation under EAOP conditions. Better understanding of these reactions and the tradeoffs between cell design and electrode geometry will impact related applications including the electrochemical Synthesis and the development of compact systems for third-world potable water, desalination, and marine applications, and other On-Site Generation of advanced oxidants.

Progress and Final Reports:

Final

SBIR Phase I:

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