New technological advancement uses an electric field to achieve efficient and low-cost ammonia removal from wastewater.
Given its environmental toxicity, ammonia is removed during wastewater purification and then used for fertilizers or fuel. However, this process is very energy and chemical intensive. Now, researchers have shown that the application of an external electric field can greatly enhance the efficiency of ammonia removal from wastewater, making it more energy- and cost-effective.
Ammonia is one of many pollutants present in wastewater and can be toxic for marine and terrestrial life. Therefore, in a process called air stripping, it is removed from wastewater and later used as a fertilizer or fuel. Air stripping converts ammonia into a gas, that can then escape the wastewater from its surface. But this process is not efficient: it is energy-intensive, and requires specific temperatures, air supply, and a lot of chemicals, making it expensive.
Addressing these drawbacks, in a study published in Water Research (made available online on August 5, 2021 and published in Volume 203 of the journal on September 15, 2021), researchers from South Korea have demonstrated that the simple 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. However, we have shown that an electrical field can also act as a modulator of this process,” says Prof. Young-Chae Song, the lead investigator on this study.
Read more at National Korea Maritime and Ocean University
Image: Improved Ammonia removal from wastewater using electric fields (Credit: National Korea Maritime & Ocean University)