Autotrophic nitrogen removal in sequencing batch biofilm reactors at different oxygen supply modes.
Autotrophic nitrogen removal in sequencing batch biofilm reactors at different oxygen supply modes.
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DOI：
10.2166/wst.2008.527
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发表时间：
2008-11
期刊：
影响因子：
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通讯作者：
C. Wantawin;J. Juateea;P. Noophan;J. Munakata-Marr
中科院分区：
文献类型：
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作者：
C. Wantawin;J. Juateea;P. Noophan;J. Munakata-Marr
传统的硝化-反硝化工艺是处理含氮废水的一种常用方法，但该工艺需要外加空气和外加碳源，对低COD/N废水处理成本较高。然而，氨可以替代地在缺氧条件下通过利用需氧自养产生的亚硝酸盐作为电子受体的自养细菌转化为二氮气体。采用接种硝化污泥的序批式生物膜反应器（SBBR），研究了典型硝化污泥启动的限氧自养硝化-反硝化工艺处理无有机碳合成氨废水的潜力。将环形编织的纤维载体（长度0.32m，表面积3.4m2/m2）垂直固定在3L反应器中。采用连续曝气控制溶解氧为1.5mg/L和间歇曝气两种不同的供气方式。在两个SBBR中均获得了超过50%的高氮去除率。在氨负荷为0.882克N/m2-天[水力停留时间（HRT）为24小时]，SBBR连续曝气到1.5毫克DO/L有略高于间歇交替SBBR（55%）的氮去除率（64%）。出水中残留氮的主要形式是氨氮，连续曝气SBBR和间歇曝气SBBR的氨氮浓度分别为25 mg/L和37 mg/L。当氨负荷降低至0.441 gm N/m2-天[HRT延长至48小时]时，氨被完全消耗。在低剩余氨浓度条件下，好氧亚硝酸盐氧化菌（ANOB）和厌氧氨氧化菌（anammox）在扩大曝气期竞争利用亚硝酸盐，导致连续曝气SBBR比间歇曝气SBBR的硝酸盐产量高，氮损失少。连续曝气和交替曝气SBBR的脱氮效率分别为80%和86%。生物膜中的特定微生物的特征在于使用荧光原位杂交。好氧氨氧化细菌（AAOB）发生并排与推定的厌氧氨氧化细菌（细胞与探针AMX 820杂交）在整个生物膜，虽然ANOB很少检测到。
Conventional nitrification-denitrification treatment is a common way to treat nitrogen in wastewater, but this process is costly for low COD/N wastewaters due to the addition of air and external carbon-source. However, ammonia may alternatively be converted to dinitrogen gas by autotrophic bacteria utilizing aerobically autotrophically produced nitrite as an electron acceptor under anoxic conditions. Lab-scale sequencing batch biofilm reactors (SBBRs) inoculated with normal nitrifying sludge were employed to study the potential of an oxygen-limited autotrophic nitrification-denitrification process initiated with typical nitrifying sludge for treating a synthetic ammonia wastewater devoid of organic carbon in one step. The ring-laced fibrous carrier (length 0.32 m, surface area 3.4 m2/m) was fixed vertically in a 3 L reactor. Two different air supply modes were applied:continuous aeration to control dissolved oxygen at 1.5 mg/L and intermittent aeration. High nitrogen removals of more than 50% were obtained in both SBBRs. At an ammonia loading of 0.882 gm N/m2-day [hydraulic retention time (HRT) of 24 hr], the SBBR continuously aerated to 1.5 mg DO/L had slightly higher nitrogen removal (64%) than the intermittently alternated SBBR (55%). The main form of residual nitrogen in the effluent was ammonia, at concentrations of 25 mg/L and 37 mg N/L in continuous and intermittent aeration SBBRs, respectively. Ammonia was completely consumed when ammonia loading was reduced to 0.441 gm N/m2-day [HRT extended to 48 hr]. The competitive use of nitrite by aerobic nitrite oxidizing bacteria (ANOB) with anaerobic ammonia-oxidizing bacteria (anammox bacteria) during the expanded aeration period under low remaining ammonia concentration resulted in higher nitrate production and lower nitrogen loss in the continuous aeration SBBR than in the intermittent aeration SBBR. The nitrogen removal efficiencies in SBBRs with continuous and alternating aerated were 80% and 86% respectively. Specific microorganisms in the biofilm were characterized using fluorescence in situ hybridization. Aerobic ammonia-oxidizing bacteria (AAOB) occurred side by side with putative anammox bacteria (cells hybridizing with probe AMX820) throughout the biofilm, though ANOB were rarely detected.