February Event, February 20th

Featuring Professor Changseok Han, PhD

Title: Micropollutant Treatment and Resource Recovery from Wastewater

Different valuable compounds such as pesticides and pharmaceutical and personal careproducts (PPCPs) have been widely synthesized to increase food production and controlhuman diseases for the advantage of human beings. As anthropogenic activities increase,their production also proportionally increases. As known, some of these artificiallysynthesized chemicals, known as micropollutants, are very persistent in the environment, and thus, they can chronically affect the health of humans and animals with very low concentrations. Different technologies are available in water and wastewater treatment facilities for their proper treatment. However, as reported, conventional water and wastewater treatment processes could not effectively degrade them; thus, it is important to develop reliable processes for their treatment.

In addition to micropollutants, wastewater contains different resources, such as ammonia, even though it is an important pollutant directly associated with the eutrophication of surface water bodies.

Advanced oxidation, employing highly reactive species (i.e., hydroxyl radicals, sulfate radicals, chlorine radicals, etc.), is a well-known technology to break down persistent contaminants in water and wastewater. UV/oxidants, catalysts/oxidants, or photocatalysis-based advanced oxidation processes (AOPs) have been extensively studied for treating recalcitrant contaminants in water. Electrodialysis (ED) is widely used to separate ammonia from wastewater and concentrate it for hydrogen production since the ED can effectively recover ammonia using ion exchange membranes in the presence of the electrical field.

This presentation will discuss micropollutants degradation by catalysts/oxidants- and UV/oxidants-based AOPs. In particular, as catalysts/oxidants-based AOPs, transition metal-modified iron oxides were newly synthesized and thoroughly characterized with XRD, XPS, SEM, TEM, zeta potential measurement, and a porosimetry analysis. The degradation of an over-the-counter painkiller, acetaminophen, was studied by the catalysts in the presence of peroxymonosulfate or peroxydisulfate. Moreover, as UV/oxidants-based AOPs, UV/chlorine was carefully studied to decompose a pesticide, carbaryl, in water. For ammonia recovery from wastewater, the ED operation was effectively investigated with different ion-exchanging membranes, gaskets, and spacers with various thicknesses. These results of micropollutant degradation by different AOPs and ammonia recovery by the ED will be provided and discussed in detail in this presentation.