Degradation of Sulfoxaflor Pesticide in Aqueous Solutions Utilizing Photocatalytic Ozonation with the Simultaneous Use of Titanium Dioxide and Iron Zeolite Catalysts

Abstract

Water pollution is a globally recognized serious problem that is hindering human development and societal progress. One of the most feasible methods to eliminate this problem is wastewater treatment and reuse. Emerging micropollutants, such as pesticides, are notorious for not being removed using traditional treatment methods. Therefore, novel techniques such as advanced oxidation processes (AOPs) have been proposed, among which photocatalytic ozonation is arguably the best option. Sulfoxaflor belongs to a relatively newer class of compounds known as sulfoximines and has not been studied for degradation using photocatalytic ozonation. In this work, we explore the degradation of sulfoxaflor, specifically a Dow product containing sulfoxaflor as an active ingredient using various AOPs, particularly photocatalytic ozonation. Photocatalytic ozonation has shown a synergy of 2.23 times compared to photocatalysis and ozonation alone. Fe-zeolite can improve the treatment time as an ozonation catalyst, reducing the removal time from 22 min to 18 min while reducing the electrical energy per order and electrical energy per order (EEO) from 69.5 to 42.92 kWh m−3 order−1. Catalysts have been characterized using scanning electron microscopy and point of zero charge. The effects of the initial concentration, UV intensity, catalyst dose, and catalyst reuse have been studied. Moreover, the rate constants have been determined using curve fitting, and the mechanism is proposed.