Applied Biochemistry and Biotechnology, Vol.193, No.2, 544-559, 2021
Responses of Nitrogen and Phosphorus Removal Performance and Microbial Community to Fe3O4@SiO(2)Nanoparticles in a Sequencing Batch Reactor
The responses of total nitrogen (TN) and total phosphorus (TP) removal performance and microbial community to 0-1.2 g/L Fe3O4@SiO(2)nanoparticles (NPs) in sequencing batch reactors were investigated. Results showed that an appropriate dose of Fe3O4@SiO(2)NPs (0.3 g/L) could promote the removal efficiency of TN and TP. High-throughput sequencing results indicated that microbial richness increased, whereas microbial diversity did not vary upon exposure to 0.1-1.2 g/L Fe3O4@SiO(2)NPs. The relative abundances ofAlphaproteobacteria,Betaproteobacteria, andGammaproteobacteriaincreased from 11.75%, 3.52%, and 6.77%, respectively, at 0 g/L Fe3O4@SiO(2)to 27.05%, 7.21%, and 14.77%, respectively, upon exposure to 0.3 g/L Fe3O4@SiO2. At the genus level, 0.3 g/L Fe3O4@SiO(2)NPs enrichednorank_f_Nitrosomonadaceae,norank_f_Xanthomonadaceae,Amaricoccus, andShinella.Real-time quantitative polymerase chain reaction results suggested that the gene copy number of ammonium-oxidizing, nitrite-oxidizing, and denitrifying bacteria population remarkably increased, whereas the number of phosphorus-accumulating organisms slightly increased under long-term exposure to 0.3 g/L Fe3O4@SiO(2)NPs. Energy-dispersive spectrum analysis showed that the phosphorus content was higher at 0.3 g/L Fe3O4@SiO(2)than at 0 g/L Fe3O4@SiO2. Nitrogen removal primarily occurred through a biological mechanism, while most phosphorus in wastewater may be removed by the combination of physicochemical and biological methods.