生物炭基Anammox颗粒污泥的培养及脱氮性能研究

Research on the Incubation and Nitrogen Removal Performance of Biochar-based Anammox Granular Sludge

针对厌氧氨氧化(Anammox)絮状污泥持留能力差的问题,采用水稻秸秆生物炭RB650作为厌氧序批式反应器(ASBR)的污泥载体,通过协同调控搅拌速率和水力停留时间的方法培养Anammox颗粒污泥,考察了培养过程中的氮转化和污泥特性变化规律,并阐述了Anammox颗粒污泥的形成机制和脱氮机理。结果表明,逐步提高搅拌速率至120 r/min并缩短水力停留时间至12 h,经58 d后可成功实现Anammox絮状污泥的颗粒化,TN去除率和容积氮去除负荷率均值分别达到90.6%和0.21 kgN/(m^(3)·d),脱氮性能优异。培养过程中,污泥湿密度、粒径、沉降速率和机械强度不断增长,最终形成颗粒感明显、结构紧实、平均粒径以2.0~2.5 mm居多的砖红色成熟颗粒污泥。RB650优良的结构特性为Anammox絮状污泥的颗粒化提供了基础。Candidatus Brocadia、Candidatus Kuenenia的相对丰度之和由13.07%增长至25.38%,是体系内的主要Anammox脱氮功能菌属;norank_c__OLB14、norank_o__SBR1031的相对丰度之和由3.40%增长至33.93%,为颗粒污泥的形成提供了骨架支撑。此外,异养反硝化、短程反硝化等脱氮途径也共同影响着最终的脱氮性能。

To address the problem of poor retention capacity of anaerobic ammonia oxidation(Anammox)flocculated sludge,rice straw biochar RB650 was used as the sludge carrier of anaerobic sequencing batch reactor(ASBR),and Anammox granular sludge was cultured through coordinated regulation of stirring rate and hydraulic retention time,and the variation pattern of nitrogen conversion and sludge characteristics during the culture process were inspected,and the formation mechanism and nitrogen removal mechanism of Anammox granular sludge were elaborated.The results indicated that the granularity of Anammox flocculent sludge could be successfully achieved after 58 days by gradually increasing the mixing rate to 120 r/min and shortening the hydraulic retention time to 12 hours,and the mean values of TN removal rate and volumetric nitrogen removal rate reached 90.6%and 0.21 kgN/(m^(3)·d),respectively,indicating superior nitrogen removal performance.During the incubation process,the wet density,particle size,settling rate and mechanical strength of the sludge increased continuously,and finally formed brick-red mature granular sludge with obvious granular feeling,compact structure,and average particle size of 2.0-2.5 mm in the majority.The excellent structural properties of RB650 provide the basis for the granulation of the Anammox flocculated sludge.Candidatus Brocadia and Candidatus Kuenenia increased from 13.07%to 25.38%in relative abundance,which were the main Anammox bacteria in the system;norank_c__OLB14 and norank_o__SBR1031 increased from 3.40%to 33.93%in relative abundance,which provided skeletal support for granular sludge formation.Also,the final nitrogen removal performance was influenced by the combination of several nitrogen removal pathways such as heterotrophic denitrification,short-range denitrification.