Anaerobic treatment of swine manure under mesophilic and thermophilic temperatures: Fate of veterinary drugs and resistance genes

Abstract

The effect of anaerobic treatment of swine manure at 35 °C (mesophilic) and 55 °C (thermophilic) on methane production, microbial community and contaminants of emerging concern was investigated. Pasteurization pretreatment and post treatment was also investigated in combination with anaerobic treatment at 35 °C. Specific methane production (SMP), 26 pharmaceutical compounds (PhACs) and five antibiotic resistance genes (ARGs) (qnrS, tetW, ermB, sul1 and blaTEM) were evaluated. Mesophilic treatment resulted in the highest SMP regardless of whether pasteurization was applied. Marbofloxacin was the most abundant antibiotic in swine manure. In general, all groups of PhACs showed higher removals under thermophilic temperatures as compared to mesophilic. In general, pasteurization pretreatment followed by mesophilic anaerobic digestion provided the highest removals of ARGs. Finally, the genera Streptococcus, Clostridium and Pseudomonas which contain pathogenic species, were present in the swine manure. Streptococcus, which was the most abundant, was decreased during all the treatments, while the others only decreased under certain treatments

S. Zahedi acknowledges the funding received from the Spanish Ministry of Science and Innovation (MICINN) (IJCI-2017-33248). This study was supported by the Spanish Government (Ministerio de Ciencia e Innovación, project PID2019- 110346RB-C22). The authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Group (ICRA-TECH - 2017 SGR 1318) and (SGR ICRA-ENV 2017 1124). ICRA researchers also acknowledge the funding from CERCA program