An Investigation Based on Removal of Ibuprofen and Its Transformation Products by a Batch Activated Sludge Process: a Kinetic Study

Abstract

Ibuprofen metabolites can form in humans as a result of metabolic activities or can be produced by microorganisms in wastewater treatment plants and receiving environments, which increases their likelihood of being present in the environment. In this study, various experiments were conducted to determine the removal degree for ibuprofen, ibuprofen carboxylic acid (IBU-CBX), and 2-hydroxylated ibuprofen (IBU-2-OH) metabolites with an activated sludge reactor. Furthermore, the pseudo-first-order biodegradation rate constant (kbiol) (17.76 L/gSSday) was calculated to determine the decomposition degree of ibuprofen in the batch activated sludge system. The effects of different ibuprofen concentrations (8.2, 5.6, 3.2, 1.51 mg/L) at constant biomass concentration (3 g/L) on the biodegradation mechanism were investigated. In addition, IBU-2-OH and IBU-CBX were tested in a batch activated sludge reactor with a volume of 2 L individually at 100 μg/L with activated sludge containing 3 g/L biomass. It was observed that ibuprofen had a removal efficiency of more than 90%. IBU-CBX and IBU-2-OH were removed at approximately 27–91% and 18–82%, respectively. In abiotic conditions, the removal of ibuprofen was found to be 7.07%. It was confirmed that the removal of ibuprofen largely depended on biological degradation. This study enabled us to know which metabolites are involved in the biodegradation process of ibuprofen in batch experiments with the activated sludge process. Copyright 2021, Yıldız Technical University.