Biological Removal of Different Concentrations of Ibuprofen and Methylparaben in a Sequencing Batch Reactor (SBR)

This study evaluated the behavior of a sequencing batch reactor (SBR) at laboratory-scale in removing the emerging contaminants, ibuprofen (IBP) and methylparaben (MPB), at different concentrations. Individual experiments were carried out for each pollutant and they were divided into six stages of operation, which included starting, load variation, and interim periods of system stabilization. The treated wastewater was synthetic, and it included the pollutions MPB or IBP, glucose as a co-substrate, macronutrients, and micronutrients. The inoculum used to start the reactor was an aerobic sludge from an SBR system used in the treatment of domestic wastewater, which presented with high-content organic material and featured good sedimentation characteristics. The removal percentages of the two compounds at concentrations of 300, 500, and 1000 mu g/L were not similar. For MPB, high removal percentages (>96 %) were obtained, while for IBP, decreasing removal percentages were found with increases in analyte concentration, exhibiting average values of 51 +/- 15.3, 26 +/- 16.6, and 16 +/- 5.4 %. Following the removal of IBP, this behavior showed pronounced effects in biomass inhibition during exposure to high concentrations of the pollutant.