Rodrigues V A J, Mac Conell E F A, Dias D F C, von Sperling M, de Araújo J C, Vasel J L
Department of Sanitary and Environmental Engineering (DESA), Federal University of Minas Gerais, Av. Antonio Carlos 6627, Escola de Engenharia, Belo Horizonte, MG, Brazil E-mail:
Department of Science and Environmental Management, Unit of Environment and Sanitation, University of Liege, Campus Arlon, Arlon, Belgium.
Water Sci Technol. 2017 Jul;76(2):268-278. doi: 10.2166/wst.2017.193.
Accumulated sludge in polishing (maturation) ponds reduces the hydraulic retention time (smaller useful volume), and this could potentially lead to a decrease in performance. However, settled biomass, present in the sediments, can contribute to nitrogen removal by different mechanisms such as nitrification and denitrification. This study investigated the influence of the bottom sludge present in a shallow maturation pond treating the effluent from an anaerobic reactor on the nitrification and denitrification processes. Nitrification and denitrification rates were determined in sediment cores by applying ammonia pulses. Environmental conditions in the medium were measured and bacteria detected and quantified by real-time polymerase chain reaction (real-time PCR). The pond showed daily cycles of mixing and stratification and most of the bacteria involved in nitrogen removal decreased in concentration from the upper to the lower part of the sludge layer. The results indicate that denitrifiers, nitrifiers and anammox bacteria coexisted in the sludge, and thus different metabolic pathways were involved in ammonium removal in the system. Therefore, the sediment contributed to nitrogen removal, even with a decrease in the hydraulic retention time in the pond due to the volume occupied by the sludge.
在精处理（熟化）池塘中积累的污泥会缩短水力停留时间（有效容积变小），这可能会导致处理效果下降。然而，沉积物中沉淀的生物质可通过硝化和反硝化等不同机制促进氮的去除。本研究调查了处理厌氧反应器出水的浅熟化池塘底部污泥对硝化和反硝化过程的影响。通过施加氨脉冲来测定沉积物柱中的硝化和反硝化速率。测量了介质中的环境条件，并通过实时聚合酶链反应（实时PCR）对细菌进行检测和定量。该池塘呈现出每日混合和分层的循环，参与氮去除的大多数细菌在污泥层中从上部到下部浓度降低。结果表明，反硝化菌、硝化菌和厌氧氨氧化菌共存于污泥中，因此系统中铵的去除涉及不同的代谢途径。因此，即使由于污泥占据的体积导致池塘水力停留时间缩短，沉积物仍有助于氮的去除。
