Acute stress of the typical disinfectant glutaraldehyde-didecyldimethylammonium bromide (GD) on sludge microecology in livestock wastewater treatment plants: Effect and its mechanisms

•GD stress affected nitrogen metabolism in the WWTP more obviously than COD removal.•Denitrifying bacteria are more tolerant to GD than AOB and NOB.•Transcripts of aminoglycoside resistance genes are more abundant when GD <1 mg/L.•Denitrifiers are the dominant genus owing to their easy access of resistance genes.•GD might induce the horizontal transfer of antibiotic resistance genes.