HRT对CSTR亚硝化颗粒污泥性能影响

Impact of Hydraulic Retention Time on Performance of Partial Nitrification Granular Sludge in Continuous Stirred-Tank Reactor

在CSTR中控制稳定的进水氨氮负荷,基于对粒径分布、胞外聚合物(EPS)组分和功能菌动力学活性的分析,考察水力停留时间(HRT)对颗粒污泥形态、氮转化效能和微生物动力学活性的影响,并采用MiSeq高通量测序技术分析污泥中微生物菌群结构.结果表明,HRT从4 h逐渐缩短至1 h,反应器中氨氮去除率从80%逐渐提高至95%,亚硝酸盐累积率始终大于85%.缩短HRT可显著改变颗粒污泥粒径分布,0.3~0.8 mm的颗粒逐渐占主导,约达50%,粒径小于0.3 mm和大于1.6 mm的颗粒逐渐减少.HRT对功能微生物活性影响与颗粒大小有关.系统中变形菌门(Proteobacteria)占绝对优势,亚硝化单胞菌属(Nitrosomomas)为代表的AOB富集度高达56%以上,缩短HRT有利于AOB的富集.

The effects of different hydraulic retention time(HRT)on short-cut nitrification granular sludge were studied in a continuous stirred-tank reactor(CSTR)by maintaining stable influent ammonia nitrogen load.Particle size distribution,extracellular polymeric substances(EPS),and functional bacterial kinetics were analyzed.The morphology of granular sludge,the performance of the CSTR,and the activity of functional microorganisms were investigated.The high throughout sequencing technology of MiSeq was employed to analyze the structure of the microbial community in sludge.The results showed that the ammonia nitrogen removal rate in the reactor was gradually increased from 80%to 95%,and the nitrite accumulation rate was always over 85%when the HRT was decreased from 4 h to 1 h.Particle size distribution of granular sludge was greatly influenced by HRT.The mass fraction of granules with a diameter smaller than 0.3 mm and larger than 1.6 mm was gradually declined,whereas the mass fraction of granules with a diameter between 0.3 mm and 0.8 mm was increased when HRT was shortened from 4 h to 1 h.The dominating proportion of granules with a diameter between 0.3 mm and 0.8 mm reached about 50%when HRT was 1 h.The impact of HRT on the activity of functional microorganisms was studied,and HRT activity was found to be closely related to the size of granular sludge.Proteobacteria were dominant in the system.AOB enrichment was represented by Nitrosomonas,which was more than 56%.Shortening HRT is beneficial for the enrichment of AOB.