Biological oxidation of Mn(II) coupled with nitrification for removal and recovery of minor metals by downflow hanging sponge reactor.
Biological oxidation of Mn(II) coupled with nitrification for removal and recovery of minor metals by downflow hanging sponge reactor.
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DOI：
10.1016/j.watres.2014.10.002
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发表时间：
2015
期刊：
影响因子：
12.8
通讯作者：
L. Cao;Hiroya Kodera;K. Abe;H. Imachi;Y. Aoi;T. Kindaichi;Tomonori Ozaki;A. Ohashi
中科院分区：
文献类型：
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作者：
L. Cao;Hiroya Kodera;K. Abe;H. Imachi;Y. Aoi;T. Kindaichi;Tomonori Ozaki;A. Ohashi
生物来源的锰氧化物(BiO-MnO2)已被证明可以吸收少量金属。异养锰氧化细菌(MnOB)的生物反应器培养可通过氧化Mn(II)产生生物MnO2，有望用于废水中微量金属的去除和回收。然而，MnOB在废水处理中的应用难度较大。本研究以MnOB为底物，研究了硝化菌产生的可溶性微生物产物(SMP)与硝化作用相结合时能否培养出MnOB。采用下流式悬挂式海绵(DHS)反应器，连续供应NH4+和Mn(II)，培养MnOB。在长期运行过程中，以48g Mnm−3d−1的速率成功地建立了Mn(II)氧化反应，并从反应器底部回收了海绵上形成的生物MnO2。结果还表明，加入到进水中的镍和钴同时被去除。微生物16S rRNA基因克隆分析鉴定了支持MnOB生长的硝化细菌，并发现只有一个枯草芽孢杆菌克隆属于一个已知的MnOB簇，这表明存在其他新的能够氧化MnOB(II)的细菌。
Biogenic manganese oxides (bio-MnO2) have been shown to absorb minor metals. Bioreactor cultivation of heterotrophic manganese oxidizing bacteria (MnOB), which produce bio-MnO2via oxidation of Mn (II), can be expected to be involved in a promising system for removal and recovery of minor metals from wastewater. However, MnOB enrichment in wastewater treatment is difficult. This study investigated whether MnOB can be cultivated when coupled with nitrification in a system in which soluble microbial products (SMP) from nitrifiers are provided to MnOB as a substrate. A downflow hanging sponge (DHS) reactor was applied for MnOB cultivation with ammonium (NH4+) and Mn (II) continuously supplied. During long-term operation, Mn (II) oxidation was successfully established at a rate of 48 g Mn m−3d−1and bio-MnO2that formed on the sponges were recovered from the bottom of the reactor. The results also revealed that Ni and Co added to the influent were simultaneously removed. Microbial 16S rRNA gene clone analysis identified nitrifiers supporting MnOB growth and showed that only one clone of Bacillus subtilis, which was affiliated with a known MnOB cluster, was present, suggesting the existence of other novel bacteria with the ability to oxidize Mn (II).