In the United States, the market for chlorine-based treatment of drinking water exceeds $20 billion and hinges on the development and transportation of bulk chlorine. While chlorine delivers reliable, cost-effective water disinfection, it carries safety and security risks associated with moving large quantities of hazardous material around the country. Dr. Brian P. Chaplin, Assistant Professor of Civil and Environmental Engineering, has secured a two-year, $83,000 National Science Foundation Small Business for Innovative Research Grant in collaboration with Advanced Diamond Technologies (ADT) to explore the development of synthetic diamond electrodes used to generate chlorine and other oxidants on-site within water treatment plants.
“On-site chlorine generation offers a safer alternative to bulk chlorine, but so far, it suffers from higher start-up costs and reliability issues,” says Dr. Chaplin. “Overcoming these technical barriers will require advances in the synthesis and large-scale manufacturing of diamond thin films – and a better understanding of their electrochemistry – within conditions needed for on-site generation.”
Dr. Chaplin is collaborating with ADT to employ boron-doped ultra-nanocrystalline diamond electrodes, developed in an earlier stage of the research, to fabricate and characterize electrochemical cells and systems for on-site generation of oxidants for water disinfection. These oxidants, which include chlorine and sodium persulphate, will be applied to targeted water treatment applications to determine efficacy. The research team will also develop strategies for increasing current efficiency and process optimization for generating these oxidants.
The team expects that the new diamond thin film electrodes will not only offer greater energy efficiency than competing electrodes, but also overcome common functionality difficulties associated with existing approaches to disinfection. They also anticipate a significant increase in flexibility for on-site generation water treatment, while at the same time dramatically reducing cost.
According to Dr. Chaplin, a better understanding of the films’ electrochemical reactions and the technological trade-offs between cell design and electrode geometry will impact related applications, such as the energy efficient electrochemical synthesis of new materials. “More broadly, this research will yield results useful for developing compact systems for potable water generation in developing countries, marine applications, and other point-of-use oxidant generation,” he says. “It may also allow scaling of on-site generation for much larger capacities, which will enable highly effective treatment of refractory organics found in oil-contaminated seawater and wastewater.”