Author(s): Laura Antinolo Bermudez; Jaime Martin Pascual; Maria Del Mar Munio Martinez; Jose Manuel Poyatos Capilla

Linked Author(s): Laura Antiñolo Bermúdez

Keywords: Wastewater; Respirometric tests; Pharmaceuticals; Membrane bioreactor

Abstract: Diclofenac and ibuprofen widely used anti-inflammatory pharmaceuticals, as well as erythromycin, a common antibiotic, belong to the group of emerging pollutant compounds. These are pharmaceuticals frequently detected in the influents of wastewater treatment plants (WWTPs). This research aims to evaluate the effect of these compounds, both individually and together, on the heterotrophic biomass present in a membrane bioreactor. Three different doping was carried out on sludge collected from membrane biorreactor (MBR) pilot plant located at the Los Vados de Granada WWTP, which operates with real urban wastewater. Once the plant was doped with pharmaceuticals commented, respirometric tests were carried out to determine the effect of the pharmaceuticals and the kinetic behaviour of the heterotrophic biomass. The criteria used for the doping of the sludge were decided for erythromycin and diclofenac based on the value of their solubility in water. In the case of ibuprofen, given its high solubility in water, the criterion of using water to establish the different doping values was the highest values found in wastewater in different areas of the world. Based on these datas, three doping tests were carried out, the first at a concentration 2,5 times lower than the value selected (Diclofenac 0,94800 mg/L; Erythromycin 0,57600 mg/L; Ibuprofen 0,05597 mg/L; Mixture: doping 1 of the 3 compounds; µm achieved was 0.0065, 0.0044, 0.0039 and 0.0176 respectively for the different experiments), the second doping test was taken as the value selected (Diclofenac 2,37000 mg/L; Erythromycin 1,44000 mg/L; Ibuprofen 0,13993 mg/L; Mixture: doping 2 of the 3 compounds; µm achieved was 0.0031, 0.0049, 0.0162 and 0.0069 respectively for the different experiments), and the third doping test was carried out at a concentration four times higher than the value selected (Diclofenac 9,4800 mg/L; Erythromycin 5,7600 mg/L; Ibuprofen 0,5597 mg/L; Mixture: doping 3 of the 3 compounds; µm achieved was 0.0043, 0.0033, 0.0176 and undetected respectively for the different experiments). The study was carried out in the steady state conditions of the membrane bioreactor pilot plant for working at 4.000 ± 597.81 mg/L MLSS and 6 hours of hydraulic retention time. The tests are carried out in batches. Once the results of the respirometric tests were obtained both in the presence and absence of pharmaceutical compounds, they were compared with each other. Tests seem to indicate that as pharmaceuticals concentration increases, heterotrophic activity decreases until inactivation occurs.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022759

Year: 2022