Insights into the removal of pharmaceutically active compounds from sewage sludge by two-stage mesophilic anaerobic digestion Gallardo Altamirano, Manuel Jesús Maza Márquez, Paula Rodelas González, María Belén Osorio Robles, Francisco Pozo Llorente, Clementina Two-stage mesophilic anaerobic digestion Sewage sludge Pharmaceutically active compounds Biogas Microbial diversity This work was funded by Spanish Ministerio de Economia y Competitividad (MINECO) and Fondo Europeo de Desarrollo Regional (FEDER) (CTM2014-60131-P). MINECO is also acknowledged for personal grants to P. Maza-Marquez (postdoctoral fellow) and M.J. Gallardo-Altamirano (FPI program, BES-2015-073595). Regional Goverment of Murcia, Spain (ESAMUR) and Murcia Water Works (EMUASA) are acknowledged for their collaboration in this research project and provision of facilities atMurcia EsteWastewater Treatment Plant (Murcia, Spain). The authors also acknowledge SCIEX for providing the loan of instrument LC/HRMS QToF X500R. The removal efficiencies (REs) of twenty-seven pharmaceutically active compounds (PhACs) (eight analgesic/ anti-inflammatories, six antibiotics, four β-blockers, two antihypertensives/diuretics, three lipid regulators and four psychiatric drugs) were evaluated in a pilot-scale two-stage mesophilic anaerobic digestion (MAD) system treating thickened sewage sludge from a pilot-scale A2O™ wastewater treatment plant (WWTP) which was fed with wastewater from the pre-treatment of the full-scaleWWTP Murcia Este (Murcia, Spain). The MAD system was long-term operated using two different sets of sludge retention times (SRTs) for the acidogenic (AcD) and methanogenic (MD) digesters (phase I, 2 and 12 days; and phase II, 5 and 24 days, in AcD andMD, respectively). Quantitative PCR (qPCR) and Illumina MiSeq sequencing were used to estimate the absolute abundance of Bacteria, Archaea, and Fungi and investigate the structure, diversity and population dynamics of their communities in the AcD and MD effluents. The extension of the SRT from 12 (phase I) to 24 days (phase II) in the MD was significantly linkedwith an improved removal of carbamazepine, clarithromycin, codeine, gemfibrozil, ibuprofen, lorazepam, and propranolol. The absolute abundances of total Bacteria and Archaeawere higher in theMD regardless of the phase, while the diversity of bacterial and archaeal communities was lower in phase II, in both digesters. Non-metric multidimensional scaling (MDS) plots showed strong negative correlations among phyla Proteobacteria and Firmicutes and between genera Methanosaeta and Methanosarcina throughout the full experimental period. Strong positive correlations were revealed between the relative abundances of Methanospirillum and Methanoculleus and the methanogenesis performance parameters (volatile solids removal, CH4 recovery rate and %CH4 in the biogas), which were also related to longer SRT. The REs of several PhACs (naproxen, ketoprofen, ofloxacin, fenofibrate, trimethoprim, and atenolol) correlated positively (r > 0.75) with the relative abundances of specific bacterial and archaeal groups, suggesting their participation in biodegradation/biotransformation pathways. 2021-09-21T07:20:07Z 2021-09-21T07:20:07Z 2021-05-21 info:eu-repo/semantics/article M.J. Gallardo-Altamirano... [et al.]. Insights into the removal of pharmaceutically active compounds from sewage sludge by two-stage mesophilic anaerobic digestion, Science of The Total Environment, Volume 789, 2021, 147869, ISSN 0048-9697, [https://doi.org/10.1016/j.scitotenv.2021.147869] http://hdl.handle.net/10481/70312 10.1016/j.scitotenv.2021.147869 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Elsevier