Annual dynamics of antimicrobials and resistance determinants in flocculent and aerobic granular sludge treatment systems

The occurrence and removal patterns of 24 antimicrobial agents resistant determinants namely 6 antibiotic resistance genes (ARGs) 2 mobile genetic elements (MGEs), the fecal indicator E. coli were investigated in three full-scale wastewater treatment plants. Their waterlines biosolids lines (including secondary based on both granular activated sludge) sampled monthly throughout one year. Samples analyzed by means LC-MS/MS, qPCR cell enumeration, respectively. influence rainfall, temperature, turbidity aforementioned was assessed through statistical linear mixed models. Ten (macrolides, fluoroquinolones, tetracyclines, sulfonamides) commonly found influent concentrations 0.1-2 µg L?1, predominant ARGs ermB sul1 (6.4 5.9 log10 mL?1 respectively). Warmer temperatures slightly reduced gene whilst increasing that produced an uneven effect across Rainfall diluted (-0.25 logs, p < 0.001) antimicrobials but not genes. absolute abundance (1.86 logs average) (2.31 average). also partly removed, 8 them still detectable after treatment, accumulated biosolids. with resembling those influent. No significant differences antimicrobials, observed when comparing conventional sludge aerobic sludge. Irrespective type significantly hydraulic loads caused rainfall (-0.35 per ? average daily flow 0.01), decreased (-0.02 ?1 nephelometric turbidy unit 0.05) .