Biological nutrient removal with low nitrous oxide generation by cancelling the anaerobic phase and extending the idle phase in a sequencing batch reactor
Biological nutrient removal with low nitrous oxide generation by cancelling the anaerobic phase and extending the idle phase in a sequencing batch reactor
复制标题
通过取消序批式反应器中的厌氧阶段并延长闲置阶段，实现低一氧化二氮生成的生物营养物去除
DOI：
10.1016/j.chemosphere.2014.02.011
复制
发表时间：
2014-08-01
期刊：
影响因子：
8.8
通讯作者：
Chen, Hong
中科院分区：
文献类型：
--
作者：
Chen, Yinguang;Wang, Dongbo;Chen, Hong
虽然废水的生物营养物去除可以通过厌氧-氧-氧交替进行来实现，但在氧相中会产生大量的氧化亚氮（N2O），其中氨氧化细菌（AOB）而不是异养反硝化菌是主要贡献者。本文报道了一种显著减少N2O生成的新策略。研究发现，通过取消厌氧阶段和延长空闲阶段，合成废水的N2O产生量减少了42%，而总氮和磷的去除率不受影响。机理研究表明，厌氧相的取消有利于异养反硝化菌代替AOB负责氧相的脱氮，增加了外部碳源驱动的总氮去除率，减少了亚硝酸盐的积累。定量实时聚合酶链反应和荧光原位杂交分析进一步表明，新策略增加了N2O还原菌的数量，但降低了以N2O为主要反硝化产物的糖原积累菌的丰度。结果表明，取消厌氧相后，一氧化氮还原酶活性与N2O还原酶活性之比明显降低。所有这些观测结果都与N2O产量的减少相一致。在实际的城市污水中，最终证实了该策略最小化N2O生成的可行性。本文的研究结果为减少废水生物脱氮产生N2O提供了新的视角。(C) 2014 Elsevier Ltd.版权所有。
Although wastewater biological nutrient removal can be achieved by alternating the anaerobic-oxicanoxic phases, significant amount of nitrous oxide (N2O) is generated in oxic phases, where ammonia-oxidizing bacteria (AOB) rather than heterotrophic denitrifiers are the main contributors. Here a new efficient strategy to remarkably reduce N2O generation was reported. It was found that by cancelling the anaerobic phase and extending the idle phase the N2O generation was reduced by 42% using synthetic wastewater, whereas the total nitrogen and phosphorus removals were unaffected. The mechanistic investigations revealed that the cancelling of anaerobic phase benefited heterotrophic denitrifiers instead of AOB to be responsible for nitrogen removal in the oxic phases, increased the ratio of total nitrogen removal driven by external carbon source, and decreased nitrite accumulation. Quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses further showed that the new strategy increased the number of N2O reducing bacteria but decreased the abundance of glycogen accumulating organisms, with N2O as their primary denitrification product. It was also determined that the ratio of nitric oxide reductase activity to N2O reductase activity was significantly decreased after anaerobic phase was cancelled. All these observations were in accord with the reduction of N2O production. The feasibility of this strategy to minimize the generation of N2O was finally confirmed for a real municipal wastewater. The results reported in this paper provide a new viewpoint to reduce N2O generation from wastewater biological nutrient removal. (C) 2014 Elsevier Ltd. All rights reserved.