Effect of Pharmaceutical Compounds (Diclofenac, Ibuprofen, and Erythromycin) on the Heterotrophic Behaviors of Biomass of a Membrane Bioreactor to Treat Urban Wastewater

The increasing prevalence of pharmaceutical substances in wastewater is emerging as a pressing ecological issue on a global scale. The purpose of this study was to evaluate the biological influence of pharmaceutical compounds on the heterotrophic biomass residing in a membrane bioreactor. The study examined the way microorganisms react to antibiotic and anti-inflammatory compounds, with the goal of proactively tackling potential issues and developing solutions that may emerge withing wastewater treatment plant bioreactors. Respirometric tests were carried out to determine the kinetic response of the heterotrophic biomass. The same study was carried out in the steady state of the plant under different conditions of hydraulic retention times (6 and 12 h) and biomass concentration (2888 +/- 371 mg/L to 7477 +/- 869 mg/L). A response surface statistical analysis was applied to determine the effect of the variables on the rate of substrate degradation for organic matter removal and the growth rate of net heterotrophic biomass. The results show that the biological response of the biomass is concerned when exposed to a combination of pharmaceutical substances such as ibuprofen, diclofenac, and erythromycin, in four cycles of operation at 16 varying concentrations of pharmaceuticals in each cycle. This suggests the presence of a synergistic effect among these pharmaceuticals, leading to a noticeable slower kinetic response in the biomass.