Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation.
Achieving Stable Nitritation for Mainstream Deammonification by Combining Free Nitrous Acid-Based Sludge Treatment and Oxygen Limitation.
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DOI：
10.1038/srep25547
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发表时间：
2016-05-06
影响因子：
4.6
通讯作者：
Yuan Z
中科院分区：
文献类型：
--
作者：
Wang D;Wang Q;Laloo A;Xu Y;Bond PL;Yuan Z
稳定的亚硝化是实现节能型主流脱氨工艺自养脱氮的关键瓶颈。在此，我们报告了一种新的策略，以洗出硝化螺旋菌属和硝化杆菌属的处理国内强度的废水。该策略结合污泥处理使用游离亚硝酸（FNA）与溶解氧（DO）的控制在亚硝化反应器。最初，硝化反应器实现了NH 4+完全转化为NO3−。然后，在侧流装置中，当每天用1.82mg N/L的FNA处理1/4的污泥24 h时，反应器中的亚硝酸盐积累达到约60%。荧光原位杂交（FISH）结果显示，FNA处理显著降低了亚硝酸盐氧化菌（NOB）的丰度（从23.0 ± 4.3%降至5.3 ± 1.9%），尤其是硝化螺菌（Nitrospira sp.）的丰度（从15.7 ± 3.9%降至0.4 ± 0.1%）。当主流反应器中DO浓度从2.5-3.0 mg/L降低到0.3-0.8 mg/L时，亚硝酸盐的积累增加到80%左右。FISH显示DO限制进一步降低了NOB的丰度（至2.1 ± 1.0%），尤其是硝酸杆菌属（从4.9 ± 1.2%降至1.8 ± 0.8%）。该策略消除了低浓度生活污水脱氨的主要障碍。
Stable nitritation is a critical bottleneck for achieving autotrophic nitrogen removal using the energy-saving mainstream deammonification process. Herein we report a new strategy to wash out both the Nitrospira sp. and Nitrobacter sp. from the treatment of domestic-strength wastewater. The strategy combines sludge treatment using free nitrous acid (FNA) with dissolved oxygen (DO) control in the nitritation reactor. Initially, the nitrifying reactor achieved full conversion of NH4+ to NO3−. Then, nitrite accumulation at ~60% was achieved in the reactor when 1/4 of the sludge was treated daily with FNA at 1.82 mg N/L in a side-stream unit for 24 h. Fluorescence in-situ hybridization (FISH) revealed FNA treatment substantially reduced the abundance of nitrite oxidizing bacteria (NOB) (from 23.0 ± 4.3 to 5.3 ± 1.9%), especially that of Nitrospira sp. (from 15.7 ± 3.9 to 0.4 ± 0.1%). Nitrite accumulation increased to ~80% when the DO concentration in the mainstream reactor was reduced from 2.5–3.0 to 0.3–0.8 mg/L. FISH revealed the DO limitation further reduced the abundance of NOB (to 2.1 ± 1.0%), especially that of Nitrobacter sp. (from 4.9 ± 1.2 to 1.8 ± 0.8%). The strategy developed removes a major barrier for deammonification in low-strength domestic wastewater.