Lux Research senior analyst Heather Landis says that Chen’s technology is unique and has potential. Other companies have used titanium dioxide in photocatalysis, but so far, no one has combined photocatalysis with electrochemistry, she says. But according to Landis, Chen will need to demonstrate the technique on wastewater samples that contain multiple contaminants, as opposed to just the pollutant nitrophenol.
Alexander Orlov, an assistant professor of materials science and engineering at Stony Brook University, in New York, says that Chen’s approach could find niche applications, particularly for treating wastewater with high concentrations of nitrophenols. However, Orlov says that one potential problem could be with the titanium dioxide catalyst, which tends to lose its reactivity over time. Further testing will have to be done to demonstrate its long-term viability, he says. While Chen acknowledges that this could be an issue, he says that overall, titanium dioxide is a good catalyst because it is chemically inert as well as nontoxic. However, Chen is also experimenting with nanostructures of titanium dioxide, which should be more resilient in the long run.
How the technique will fare compared with biological treatment is still unknown. Because biological treatment uses bacteria and requires little in the way of upkeep, it is relatively low cost. Chen says that biological treatment will be cheaper at least at first. But because his method is superior at removing nitrophenols, he believes that it could be used in conjunction with biological treatment, particularly for treating heavily contaminated industrial or agricultural wastewater. Chen says that his approach could also have a leg up on types of water treatment that use chemical treatments such as chlorine, which are less environmentally friendly.
The next step is to test the method on other pollutants, perform a cost analysis, and scale the process up. Chen says that his group is now working on building a prototype treatment plant, which should be completed by the end of the year.