Biodegradation of Acetaminophen in Activated Sludge Batch Reactors

Abstract

The purpose of this research is to determine if acetaminophen with biodegrade in traditional activated sludge batch reactors. Abiotic, aerated activated sludge and anaerobic sludge reactors were investigated, and were inoculated with acetaminophen or p-aminophenol, which is a common degradation product of acetaminophen. Each sample was filtered to remove biomass, and UV-Vis spectrophotometry was used to detect analyte concentrations. The biodegradation results were fit with first-order kinetic models. Findings and Conclusions: It was found that acetaminophen degrades abiotically to p-aminophenol, and finally to an unknown colored compound under certain conditions. However, without the presence of oxygen and a catalyst, the reaction was not observed. Aeraobic activated sludge was successful in biodegrading both acetaminophen and p-aminophenol, with a biodegradation rate of 0.34 day-1 and 1.462 day-1, respectively. The anaerobic activated sludge proved inconclusive in the biodegradation of these two compounds. There was positive interference observed, as well as an absence of any biodegradation. Further study needs to be done with a different method of instrumentation to investigate concentrations commonly found in the environment. Additional studies with the anaerobic activated sludge should be completed to determine the biodegradation kinetics.