College of Environment and Ecology, Chongqing University, No. 174 Shazhengjie, Shapingba District, Chongqing, 400045, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, No. 266 Fangzheng Avenue, Shuitu Hi‑tech Industrial Park, Shuitu Town, Beibei District, Chongqing, 400714, China.
Bioprocess Biosyst Eng. 2020 Jun;43(6):1037-1049. doi: 10.1007/s00449-020-02302-y. Epub 2020 Feb 4.
The one-stage partial nitritation-anammox (PN-A) process is considered an efficient process for low-cost nitrogen removal. In this study, the nitrogen removal performance of different-sized granules in a one-stage PN-A reactor was studied. The total autotrophic nitrogen removal rate (TANRR) of the granular sludge increased as the granule size increased, and the TANRR of granular sludge with a radius larger than 500 μm reached 0.14 kgN kgVSS d. High-throughput sequencing revealed that the abundance of ammonium-oxidizing bacteria and anaerobic ammonium-oxidizing (anammox) bacteria in granular sludge of different sizes differed, indicating that the bacterial community structure was affected by the granule size. The TANRR of different-sized granules was affected by the volumes of aerobic micro-zone and anaerobic micro-zone inside the granule. Appropriate micro-zone volumes inside the granules could be regulated by the dissolved oxygen (DO) concentration of the reactor, which are favourable for achieving a balance between partial nitritation and anammox and then satisfactory nitrogen removal. Small-volume variations in the range of micro-zones have a significant influence on the balance between partial nitritation and anammox. The proper DO concentration required for different-sized granules to achieve better nitrogen removal differed. This study provides a novel perspective for understanding the effect of micro-zones of granular sludge on one-stage PN-A nitrogen removal.
单级短程硝化-厌氧氨氧化（PN-A）工艺被认为是一种低成本脱氮的有效方法。本研究考察了单级 PN-A 反应器中不同粒径颗粒的脱氮性能。颗粒污泥的总自养脱氮速率（TANRR）随粒径的增大而增大，粒径大于 500μm 的颗粒污泥的 TANRR 达到 0.14kgNkgVSS·d。高通量测序结果表明，不同粒径颗粒污泥中的氨氧化菌和厌氧氨氧化菌（anammox）的丰度存在差异，表明细菌群落结构受到颗粒粒径的影响。不同粒径颗粒的 TANRR 受颗粒内部好氧微区和厌氧微区的体积影响。通过控制反应器的溶解氧（DO）浓度，可以调节颗粒内部合适的微区体积，有利于实现部分硝化和厌氧氨氧化之间的平衡，从而达到满意的脱氮效果。微区体积的微小变化对部分硝化和厌氧氨氧化的平衡有显著影响。不同粒径颗粒达到更好脱氮效果所需的合适 DO 浓度不同。本研究为理解颗粒污泥微区对单级 PN-A 脱氮的影响提供了新的视角。
