硼对受高氨氮冲击后短程硝化系统效能恢复的影响研究

Effect of boron on the recovery of nitrification efficiency after high ammonia nitrogen impact

通过提高进水氨氮使稳定运行的短程硝化系统受到抑制,然后向反应器中投加硼来促进短程硝化效能的恢复。通过氮转化能力、氨氧化菌活性、胞外聚合物(EPS)中蛋白质(PN)和多糖(PS)含量、污泥形态和颗粒污泥的粒径分布来对短程硝化系统的变化进行表征。结果表明,稳定运行的短程硝化系统在短时间内受到800 mg/L氨氮冲击后短程硝化效能下降,污泥稳定性减弱,且在氨氮重新恢复到200 mg/L后短期内其效能仍无法恢复;与抑制期相比,投加硼后系统在恢复期的氨氮去除率从50%上升到95%,亚硝酸盐积累率从50%上升到85%,硝酸盐积累率从50%下降到15%,反应器的比氨氮氧化速率(SAOR)从18.65 mg/(g·h)上升到38.36 mg/(g·h),比耗氧速率(SOUR)从47.68 mg/(g·h)增加到54.24 mg/(g·h),MLSS增加了32%,达到4.5 g/L,EPS中PN质量分数比抑制期增加23%,m(PN)/m(PS)增加35.96%,信号分子AI-2质量浓度也从0.021 ng/mL增加到0.124 ng/mL。该研究结果阐明了硼对受高氨氮冲击下短程硝化系统效能的恢复有促进作用。

By increasing the concentration of ammonia nitrogen,the stable nitrification system was inhibited,and then boron was added to the reactor to improve the recovery of nitrification efficiency.The changes of the short-range nitrification system were characterized by the nitrogen conversion capacity,the activity of ammonia-oxidizing bacteria,the content of protein and polysaccharide,the morphology of sludge,and the particle size distribution of granular sludge.The results showed that the stable short-range nitrification system was affected by 800 mg/L ammo-nia nitrogen in a short period of time,and the stability of the sludge was weakened,and it could not be recover in the short term when the ammonia nitrogen concentration returned to 200 mg/L.Compared with the inhibition period,the re-moval rate of ammonia nitrogen increased from 50%to 95%during the recovery period.The accumulation rate of ni-trite increased from 50%to 85%,the accumulation rate of nitrate decreased from 50%to 15%,and the specific am-monia nitrogen oxidation rate(SAOR)increased from 18.65 mg/(g·h)to 38.36 mg/(g·h).Specific oxygen consump-tion rate(SOUR)increased from 47.68 mg/(g·h)to 54.24 mg/(g·h),MLSS increased by 32%to 4.5 g/L,PN mass frac-tion in EPS increased by 23%and m(PN)/m(PS)increased by 35.96%compared with the inhibition stage.The con-centration of the signal molecule AI-2 also increased from 0.021 ng/mL to 0.124 ng/mL.Therefore,this study illus-trated that boron could promote the recovery of short-range nitrification system performance under the impact of high ammonia nitrogen concentration.