Mechanism of the effect of graphene oxide on nitrogen removal performance of activated sludge
Three sequencing batch reactors(SBRs)with different concentrations of graphene oxide(GO.0.1 and 10mg/L)were established to clarify the intrinsic mechanism of GO deteriorating the nitrogen removal performance of activated sludge(AS).The results showed that 1mg/L GO had no significant inhibitory effect on the performance of AS.10mg/L GO reduced the total nitrogen(TN)removal efficiency of AS by 17.63%.Moreover.GO exposure increased the oxidative stress levels in AS by 198.51%and 307.13%.respectively.The microorganisms responded to the GO stress by secreting more extracellular polymers(EPS).16S rRNA gene sequencing showed that GO significantly affected the abundance of genera with nitrogen removal function.The abundance of common genera responsible for nitrification(Nitrosomonas and Nitrospira)and denitrification(Candidatus_Accumulibacter.and Thauera.etc.)decreased with increasing GO concentration.Functional gene prediction showed that GO reduced the abundance of genes related to nitrogen removal.The abundance of genes related to NH4+-N oxidation(amoA.amoB.amoC)and NO2--N reduction(nirK.nirS)decreased significantly with the accumulation of GO.In this study.the intrinsic mechanism of effect on nitrogen removal performance by GO was deeply analyzed from the perspective of functional genes.
graphene oxidenitrogen removal performanceextracellular polymeric substancemicrobial community structurefunctional genes
NETL
NSTL
万方数据
