出水回流对Anammox颗粒特性及其微生物群落的影响

基于有无回流的EGSB反应器中厌氧氨氧化颗粒污泥的内外部结构和微生物群落差异,从传质、活性和稳定性等角度分析了出水回流对颗粒污泥结构和功能的影响.研究表明,增加回流提供更好的水流条件使得底物能更好的与颗粒污泥接触,反应器在氮负荷率为(3.48±0.32)kg N/(m3·d)的条件下亚硝氮和氨氮的去除率从60％和65％...

The effects of effluent reflux on characteristics and microbial community of anammox granular sludge

From the perspectives of mass transfer, anammox activity and stability, this study evaluated the effect of effluent reflux on the structure and function of Anammox granular sludge (AnGS) in EGSB reactor with or without reflux. The results showed that increased reflux provided better flow conditions, which enabled the substrate to better contact with granular sludge. When nitrogen load rate ranged from (3.16to 3.79) kg/N·(m³·d), the original removal rates of nitrite (60%) and ammonia nitrogen (65%) were increased to more than 95% and the specific anammox activity increased by 31.54%. With the increased gas production and granular activity by reflux, the internal pressure of bubbles in AnGS was increased due to the limited pore volume. The microstructure of AnGS was changed and the porosity of AnGS was increased from 41.3% to 59.4%. In addition, the higher shear force and better mass transfer effect caused by effluent reflux greatly improved the stability of AnGS. The effluent reflux maintained and enriched candidatus-Jettenia in the seed AnGS, and enabled some bacteria maintaining the stability of the AnGS and improving viability. The internal porous structure and efficient nitrogen removal of the AnGS (such as Simplicispira) leads to better stability (such as Rheinheimera), which is conducive to the stable operation of AnGS in practical engineering applications.