Department of Biotechnology, Universidad Autónoma Metropolitana-Iztapalapa, Iztapalapa, Mexico City CP 09340, Mexico.
Appl Biochem Biotechnol. 2013 Feb;169(3):990-1000. doi: 10.1007/s12010-012-0065-2. Epub 2013 Jan 8.
The effect of 2-chlorophenol (2-CP) on ammonium and nitrite-oxidizing processes was kinetically evaluated in batch cultures with nitrifying sludge at steady state. Assays with ammonium or nitrite as energy source and 2.5, 5.0, or 10.0 mg 2-CP-C/l were conducted. Control assays without 2-CP were also performed. Ammonium-oxidizing activity was completely inhibited at the different 2-CP concentrations, whereas nitrite-oxidizing activity was present as nitrite was completely consumed and converted to nitrate irrespectively of 2-CP concentration. In the presence of 2.5 and 5.0 mg 2-CP-C/l, no significant effect on specific rates of nitrite consumption and nitrate production was observed, but a significant decrease on these parameters was observed at 10.0 mg 2-CP-C/l. The nitrifying sludge previously exposed to 2-CP was unable to completely recover its ammonium and nitrite oxidation capacity. Nevertheless, complete 2-CP consumption was achieved in all assays. The effect of 2-CP on ammonium oxidation was observed at kinetic and metabolic pathway level, whereas the effect on nitrite oxidation was observed only at kinetic level. The results obtained in this work evidenced that in order to achieve a successful nitrification process the presence in wastewater of even 2.5 mg 2-CP-C/l should be avoided.
采用稳定状态下的硝化污泥进行批量培养，从动力学角度评价了 2-氯苯酚（2-CP）对氨氮和亚硝酸盐氧化过程的影响。以氨氮或亚硝酸盐为能源，进行了 2.5、5.0 或 10.0 mg 2-CP-C/L 的试验，同时还进行了不含 2-CP 的对照试验。在不同的 2-CP 浓度下，氨氮氧化活性完全受到抑制，而亚硝酸盐氧化活性仍然存在，因为亚硝酸盐被完全消耗并转化为硝酸盐，与 2-CP 浓度无关。在 2.5 和 5.0 mg 2-CP-C/L 的存在下，观察到对亚硝酸盐消耗和硝酸盐生成的比速率没有显著影响，但在 10.0 mg 2-CP-C/L 时观察到这些参数显著下降。先前暴露于 2-CP 的硝化污泥无法完全恢复其氨氮和亚硝酸盐氧化能力。然而，在所有试验中都实现了 2-CP 的完全消耗。2-CP 对氨氮氧化的影响在动力学和代谢途径水平上观察到，而对亚硝酸盐氧化的影响仅在动力学水平上观察到。本工作的结果表明，为了实现成功的硝化过程，即使废水中存在 2.5 mg 2-CP-C/L 的 2-CP 也应予以避免。
