驯化后的聚糖菌对NO2——N和NO3——N内源反硝化速率的影响

在序批式（sequencing batch reactor，SBR）反应器中，通过分段厌氧-好氧（厌氧后排水）运行方式，在以葡萄糖为碳源、P/C比小于2/100的条件下，成功实现了聚糖菌（glycogen accumulating organisms，GAOs）的驯化富集，厌氧段磷酸盐的释放量（phosphorus release amounts，PRA）稳定在1.0 mg·L^-1以内，胞内糖原（glycogen，gly）含量是初始阶段的1.2倍。驯化后的GAOs分别以NO₂^--N、NO₃^--N为电子受体经厌氧-缺氧运行方式，可进行内源反硝化反应过程。GAOs在内源反硝化过程中依次利用胞内的聚β-羟基戊酸酯（poly-β-hydroxyvalerate，PHV）、聚β-羟基丁酸酯（poly-β-hydroxyvalerate，PHB）和gly作为内碳源。在22℃时，反硝化聚糖菌（denitrifying glycogen accumulating organisms，DGAOs）以NO₂^--N、NO₃^--N为电子受体平均比内源反硝化速率分别为0.067 g N·（g VSS）^-1·d^-1、0.023 g N·（g VSS）^-1·d^-1，常温短程内源反硝化速率约是全程内源反硝化速率的3倍。

Effect of endogenous denitrification rate of domesticated GAOs on NO2--N and NO3--N

Glycogen accumulating organisms (GAOs) has been enriched in the anaerobic-aerobic sequencing batch reactor (AO-SBR) (drained after anaerobic) with glucose as the carbon source and the P/C ratio less than 2/100. PRA was less than 1.0 mg·L^-1. The content of gly was 1.2 times the initial stage of GAOs enrichment. The domesticated GAOs cultured in anaerobic-anoxic operation could proceed endogenous denitrification reaction with NO₂^--N and NO₃^--N as endogenous carbon source. GAOs used intracellular poly-β-hydroxyvalerate (PHV), poly-β-hydroxyvalerate (PHB) and glycogen (gly) in turns as carbon source in endogenous denitrification process. The average endogenous denitrification rate of DGAOs using NO₂^--N and NO₃^--N as electron acceptors were 0.067 g N·(g VSS)^-1·d^-1 and 0.023 g N·(g VSS)^-1·d^-1 at 22℃, respectively. Short-range endogenous denitrification rate was about three times as much as endogenous denitrification rate at normal temperature.