Performance evaluation of structured and packed bed reactor for removal of sulfamethoxazole and ciprofloxacin

Abstract

The occurrence, fate and potential impacts of antibiotics in the environment has attracted attention of researchers around the world in recent years. Although the concentration of antibiotics and their metabolites is considered low (around ng/L or µg/L) in the different environmental compartments, they are considered emerging contaminants because they can result in the development and spread of resistance genes in bacteria. This can lead in long-term impacts on the ecosystem, human health and even the economy, since these compounds are losing their antimicrobial effectiveness. Among the antibiotics, Sulfamethoxazole (Sulfonamide class) and Ciprofloxacin (Fluoroquinolone class) are the most frequently detected in various environmental matrices and are used in human and veterinary medicine. Currently studies of behavior and degradation of antibiotics are focused more in advanced physical-chemical processes (ozonation, activated carbon adsorption, ion exchange, membrane filtration, advanced oxidation processes) and aerobic biological processes (Activated Sludge and Membrane Bioreactors - MBR), and there are few studies focusing on anaerobic biodegradation processes for these compounds. Therefore, this study sought to determine the behavior of two anaerobic fixed bed reactors - structured and packed - in removing and biodegradation of Sulfamethoxazole and Ciprofloxacin, serving as a basis for comparison with other configurations of anaerobic reactors as UASB (Upflow Anaerobic Sludge Blanket) and HAIB (Horizontal-flow Anaerobic Immobilized Biomass), and also with the existing aerobic systems. Furthermore, it is expected detect and quantify the possible metabolites formed, as well as to obtain the kinetic parameters of the degradation and perform ecotoxicological assays with the above pharmaceuticals. (AU)