Study: Better Treatments to Remove PCPs from Wastewater

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A new study of seven wastewater treatment plants across the Eastern United States revealed mixed results with currently used methods to remove medicines and other personal care products (PCPs). The technologies to ensure removal are available today, but upgrades to treatment facilities are prohibitively expensive.

Of the 10 treatment steps Diana Aga, professor of chemistry at the University of Buffalo, studied, only two were particularly promising. Granular activated carbon and ozonation both reduced the concentration of pharmaceuticals in water by more than 95 percent.

Activated sludge, the industry standard, was found to be less effective at destroying persistent drugs, including certain antidepressants and antibiotics. However, the process, which uses microorganisms to break down organic contaminants, was found to be effective in removing nutrients, such as nitrogen and phosphorus, allowing the treated wastewater to be released back into the environment without causing excessive damage.

Aga told Laboratory Equipment her findings point to the success of a “multiple treatment process.”

“Our study shows that highly persistent pharmaceuticals that are not typically biodegraded in conventional activated sludge systems can be removed using ozonation,” she explained. “However, to reduce potential ecotoxicity of the treated effluent after ozonation, activated carbon may be necessary after ozonation. Therefore, the concept of multiple barrier treatment is important in the system design if the ultimate goal is to use the reclaimed water back into potable use.”

For both conservation and supply purposes, reclaiming wastewater for potable use is the pinnacle. Once the construction of the Advanced Water Purification Facility (AWPF) in El Paso, Texas is complete in 2023, the facility will be the first in the nation to distribute treated wastewater directly to a city’s drinking water distribution system. Once operating, the AWPF will produce up to 10 million gallons per day of renewable, drought-proof water to supplement the city's drinking water supplies.

Still, there is a lot on the technology side that can/needs to be done to ensure wastewater is safe for the environment and people.

“At this time, the processes we examined are expensive for treatment plants,” said Aga, “but scientists and engineers are constantly doing research to make things better and more cost effective.  I wouldn’t be surprised if in the near future a less expensive, more innovative way to reduce the presence of pharmaceuticals and other micropollutants in wastewater is implemented.”

Aga herself is part of a collaborative study that may do just that. The group is studying the use of urine-diverting toilets at homes and offices to reduce the amounts of pharmaceuticals that go into wastewater treatment plants, while also sequestering nitrogen and phosphorus for fertilizer use.

Next, Aga intends to investigate perfluoroalkyl substances (PFASs) in wastewater and drinking water. Recently, PFASs have received attention because of their persistence in the aquatic environment, and possible toxicological effects on marine life.

Photo: UB chemistry professor Diana Aga (right) and UB chemistry Ph.D. candidate Luisa Angeles in the lab. To study pharmaceuticals in wastewater, they use the system pictured to isolate chemical compounds from the wastewater. Credit: Meredith Forrest Kulwicki/UB