Bioaugmentation as a tool to protect the structure and function of an activated-sludge microbial community against a 3-chloroaniline shock load
Bioaugmentation as a tool to protect the structure and function of an activated-sludge microbial community against a 3-chloroaniline shock load
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DOI：
10.1128/aem.69.3.1511-1520.2003
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发表时间：
2003-03-01
影响因子：
4.4
通讯作者：
Siciliano, SD
中科院分区：
文献类型：
--
作者：
Boon, N;Top, EM;Siciliano, SD
生物反应器的生物强化侧重于去除异种生物，而很少注意恢复被破坏的反应器功能，如氨氮的去除。氯苯胺在工业中广泛用作各种产品的前体，偶尔会排放到废水中。本研究评估了3-氯苯胺（3-CA）脉冲对活性污泥反应器功能的影响，以及接种3-CA降解菌株Comamonas testosterone i2gfp对活性污泥反应器的生物增强作用。研究了硝化、除碳和污泥压实等功能的变化与污泥群落结构的关系，特别是硝化种群。利用变性梯度凝胶电泳（DGGE）、实时PCR和荧光原位杂交（FISH）对3-CA冲击负荷后的氨氧化微生物群落进行了表征和计数。3-CA冲击后2天，氨积累，在非生物强化反应器中，硝化活性在12天内没有恢复。相比之下，生物强化反应器中的硝化作用在第4天开始恢复。DGGE图谱、FISH和real-time PCR数据显示，生物增强反应器中氨氧化微生物群落在结构、活性和丰度上均有所恢复，而非生物增强反应器中氨氧化菌核糖体数量急剧减少，群落组成发生变化且未恢复。3-CA的添加对活性污泥的沉降性有负影响，污泥体积指数增加了2.3倍。在非生物强化反应器中，3-CA冲击2天后，化学需氧量（COD）去除率下降了36%，但在第4天完全恢复。相反，在生物强化反应器中，COD去除率没有下降。该研究表明，废水反应器的生物强化加速了有毒氯化有机物（如3-CA）的降解，保护了硝化细菌群落，从而使毒性休克恢复得更快。
Bioaugmentation of bioreactors focuses on the removal of xenobiotics, with little attention typically paid to the recovery of disrupted reactor functions such as ammonium-nitrogen removal. Chloroanilines are widely used in industry as a precursor to a variety of products and are occasionally released into wastewater streams. This work evaluated the effects on activated-sludge reactor functions of a 3-chloroaniline (3-CA) pulse and bioaugmentation by inoculation with the 3-CA-degrading strain Comamonas testosteroni I2 gfp. Changes in functions such as nitrification, carbon removal, and sludge compaction were studied in relation to the sludge community structure, in particular the nitrifying populations. Denaturing gradient gel electrophoresis (DGGE), real-time PCR, and fluorescent in situ hybridization (FISH) were used to characterize and enumerate the ammonia-oxidizing microbial community immediately after a 3-CA shock load. Two days after the 3-CA shock, ammonium accumulated, and the nitrification activity did not recover over a 12-day period in the nonbioaugmented reactors. In contrast, nitrification in the bioaugmented reactor started to recover on day 4. The DGGE patterns and the FISH and real-time PCR data showed that the ammonia-oxidizing microbial community of the bioaugmented reactor recovered in structure, activity, and abundance, while the number of ribosomes of the ammonia oxidizers in the nonbioaugmented reactor decreased drastically and the community composition changed and did not recover. The settleability of the activated sludge was negatively influenced by the 3-CA addition, with the sludge volume index increasing by a factor of 2.3. Two days after the 3-CA shock in the nonbioaugmented reactor, chemical oxygen demand (COD) removal efficiency decreased by 36% but recovered fully by day 4. In contrast, in the bioaugmented reactor, no decrease of the COD removal efficiency was observed. This study demonstrates that bioaugmentation of wastewater reactors to accelerate the degradation of toxic chlorinated organics such as 3-CA protected the nitrifying bacterial community, thereby allowing faster recovery from toxic shocks.