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Study improves ammonia removal in drinking water treatment

Nov. 29, 2021

Research from South Korea uses an electric field to substantially improve the ammonia removal efficiency in drinking water treatment.

Treatment Plant Wastewater 2826986 1920 61a5153da5bbc

Researchers have shown that the application of an external electric field can greatly enhance the efficiency of ammonia removal from wastewater — a process normally resource and energy intensive.

The process of air stripping for ammonia removal can be expensive, requiring specific temperatures, air supply, and a lot of chemicals. Addressing these drawbacks in a study published in Water Research, researchers from Korea Maritime & Ocean University found that the application of an electric field during air stripping can substantially improve the efficiency of ammonia removal, even under sub-optimal conditions.

“So far, the removal of ammonia from wastewater was thought to be dependent on only pH, temperature, and air supply,” says Young-Chae Song, the lead investigator on this study. “However, we have shown that an electrical field can also act as a modulator of this process,”

An infographic to help illustrate the electric field's effects on ammonia removal.

Song and his team used a combination of live experiments with an ammonia stripping tank and deep learning to understand how electric fields of different strengths influence the efficiency of ammonia removal from wastewater. They found that electric fields with an alternating current of 50 MHz and a power of 15 V/cm significantly improves the ammonia removal efficiency — increasing it from 51 percent to 94 percent, even under sub-optimal conditions. Improved ammonia yields could be achieved while considerably reducing the consumption of energy and chemicals.

Prof. Song comments, “Our simulations showed that electric field application provides a similar efficiency of ammonia removal to conventional methods at a much lower temperature, air supply, and pH. Moreover, the energy needed to power the electric field is a minute fraction of the energy required to achieve these ‘optimal’ conditions.”

An electric field-coupled platform could provide a more economical way of stripping ammonia from wastewater and reducing the carbon footprint associated with this process.

Young-Chae Song, et al. “External electric field promotes ammonia stripping from wastewater.” Water Research 203 (2021). https://doi.org/10.1016/j.watres.2021.117518.