What's in your water? The answer is not always clear, but is of paramount to quality of life and public health.
At the College of Engineering, researchers are working on ways to make water safer and healthier. Led by Dr. Rominder Suri, Chair of Civil and Environmental Engineering, heads up the Water and Environment Technology Center. Located at the College of Engineering, the WET Center works to devise novel methods to remove pollutants from water. The Center opened in 2009 as a partnership with the National Science Foundation as an Industry/University Cooperative Research Center.
"When the WET Center was founded in 2009; the original mission was to focus on the study and treatment of emerging contaminants of concern (ECs)," Dr. Suri said. "In the second phase of the center, the WET Center has broadened its mission to include traditional contaminants as well. This allowed the WET Center to apply the technology developed at the Center to a broader set of applications and provide additional value to our members. In addition, the Center research evolved from bench or beaker scale to pilot scale, wherein the technologies were scaled up."
One of the contaminants the WET Center has focused on removing from water supplies in 1,4-dioxane, the classified ether that has been used as a solvent, a corrosion inhibitor, and stabilizer. It is not uncommon to find it at Department of Defense sites. In water supplies, 1,4-dioxane is considered a carcinogen, and is highly mobile in contaminated water. Even less than one part per billion in water can increase the risk of cancer.
In April, Dr. Suri and his team at the WET Center published a study that showed a new way to remove dioxane from water supplies. Introducing ozone to a contaminated sample has been able to remove dioxane by oxidation processes. Often, it's used with hydrogen peroxide, which creates other chemical concerns. Also, ultrasound waves can free the contaminants by producing radicals. Combining the two greatly increases the elimination of dioxane, which Dr. Suri's group took a step further by examining the effect of ozone levels, pH, and time on this process.
Using aqueous ozone pumped through a generator into samples with dioxane introduced to Philadelphia drinking water, the experiments tested ozone alone versus adding ultrasound to the process. The experiments verified previous studies that found introducing ultrasound increased removal rates.
With higher ozonation constant rates than previous studies, Dr. Suri's team also found that lower amounts of aqueous ozone removed more dioxane over longer time frames than increasing the ozone in a shorter period. Increasing the pH levels of the water also helped in the removal process. In addition, utilizing the ultrasound eliminated the formation of bromate, often a by-product of the ozonation process.
The two require just one electrical source to create both, simplifying the removal procedures.