Department of Hydraulics and Sanitation, University of São Paulo (USP), São Carlos School of Engineering, Av. Trabalhador São-carlense, 400-São Carlos-SP, 13566-590, Brazil.
Water Sci Technol. 2011;64(8):1607-13. doi: 10.2166/wst.2011.716.
The good composition and activity of biofilms are very important for successful operation and control of fixed-film biological reactors employed in liquid effluents treatment. During the last decade, microsensors have been applied to study microbial ecology. These sensors could provide information regarding the microbial activity concerning nitrification and denitrification that occur inside biofilms. Other techniques of molecular biology, such as fluorescence in situ hybridization (FISH), have also contributed to this matter because their application aids in the identification of the bacterial populations that compose the biofilms. The focus of this paper was to study the loading rate and surface velocity to promote the development of nitrifying biofilms in three distinct flow cells that were employed in the post treatment of a synthetic wastewater simulating the effluent from a UASB (Upflow Anaerobic Sludge Blanket) reactor. Using the FISH technique, it was found that the population of ammonia-oxidizing-bacteria was greater than that of nitrite-oxidizing-bacteria; this was also supported by the lower production of nitrate determined by physicochemical and microsensor analyses. It was verified that the loading rate and surface velocity that promoted the greatest nitrogen removal were 0.25 g N-amon m(-2)biofilm day(-1) and 1 m h(-1), respectively.
生物膜的良好组成和活性对于在液体废水处理中使用的固定膜生物反应器的成功运行和控制非常重要。在过去的十年中，微传感器已被应用于研究微生物生态学。这些传感器可以提供有关硝化和反硝化微生物活性的信息，这些反应发生在生物膜内部。其他分子生物学技术，如荧光原位杂交（FISH），也对此做出了贡献，因为它们的应用有助于识别组成生物膜的细菌种群。本文的重点是研究负荷率和表面速度，以促进三种不同的流动池中的硝化生物膜的发展，这些流动池用于模拟 UASB（上流厌氧污泥床）反应器出水的合成废水的后处理。使用 FISH 技术，发现氨氧化菌的数量大于亚硝酸盐氧化菌的数量；这也得到了物理化学和微传感器分析确定的硝酸盐产量较低的支持。验证了促进最大氮去除的最佳负荷率和表面速度分别为 0.25 g N-amon m(-2)biofilm day(-1)和 1 m h(-1)。
