Environmental Engineering Division, School of Mechanical & Building Sciences, VIT University, Vellore 632014, India.
J Hazard Mater. 2009 Dec 15;172(1):280-8. doi: 10.1016/j.jhazmat.2009.07.006. Epub 2009 Jul 8.
A novel route of anoxic ammonia removal in the presence of organic carbon was identified recently from ecosystems contaminated with ammonia. Sequencing batch reactor (SBR) studies were carried out in anoxic condition at oxidation-reduction potential varied from -185 to -275 mV for anoxic ammonia oxidation with adapted biomass (mixed culture). SBR studies were carried out in absence and in the presence of externally added organic carbon and/or in the presence of inorganic electron acceptors like NO2(-), NO3(-) and SO4(2-). The results showed anoxic ammonia oxidation to nitrate (in contrast to reported anammox process) in the presence of organic carbon available through endogenous respiration whereas anoxic ammonia oxidation was effective in the presence of externally added organic compound for nitrogen removal. The presence of externally added inorganic electron acceptors like NO2(-), NO3(-) and SO4(2-) was effective in anoxic ammonia oxidation, but failed to follow the reported anammox reaction's stoichiometry in nitrogen removal in the presence of organic carbon. However, the presence of NO2(-) affected best in total nitrogen removal compared to other electron acceptors and maximum ammonia removal rate was 100 mg NH4(+)/g MLVSS/d. Based on the results, it is possible to suggest that rate of anoxic ammonia oxidation depends up on the respiration activities of mixed culture involving organic carbon, NO2(-), NO3(-) and SO4(2-). The process shows possibilities of new pathways of ammonia oxidation in organic contaminated sediments and/or wastewater in anoxic conditions.
最近在受氨污染的生态系统中发现了一种新的缺氧氨去除途径，该途径存在有机碳。在氧化还原电位从-185 到-275 mV 的缺氧条件下，采用适应生物量（混合培养物）在缺氧条件下进行了序批式反应器（SBR）研究，以进行缺氧氨氧化。在不存在外加有机碳和/或存在外加无机电子受体如 NO2(-)、NO3(-) 和 SO4(2-)的情况下进行了 SBR 研究。结果表明，在存在可通过内源性呼吸获得的有机碳的情况下，缺氧氨氧化为硝酸盐（与报道的厌氧氨氧化过程相反），而在外加有机化合物存在的情况下，缺氧氨氧化可有效去除氮。外加无机电子受体如 NO2(-)、NO3(-) 和 SO4(2-) 的存在可有效进行缺氧氨氧化，但在存在有机碳的情况下，无法遵循报道的厌氧氨氧化反应在氮去除方面的化学计量。然而，与其他电子受体相比，NO2(-) 的存在对总氮去除的影响最大，最大氨去除速率为 100 mg NH4(+)/g MLVSS/d。根据这些结果，可以提出缺氧氨氧化的速率取决于混合培养物的呼吸活动，涉及有机碳、NO2(-)、NO3(-) 和 SO4(2-)。该过程表明在缺氧条件下，有机污染沉积物和/或废水中可能存在新的氨氧化途径。
