BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure links 653, Gent 9000, Belgium; Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Antônio Carlos 6627, Belo Horizonte/MG 31270-901, Brazil.
Department of Civil Engineering, Federal University of Juiz de Fora, Rua José Lourenço Kelmer, Juiz de Fora - MG, 36036-900, Brazil.
Water Res. 2021 Aug 1;201:117337. doi: 10.1016/j.watres.2021.117337. Epub 2021 Jun 7.
Anaerobic sewage treatment is a proven technology in warm climate regions, and sponge-bed trickling filters (SBTFs) are an important post-treatment technology to remove residual organic carbon and nitrogen. Even though SBTFs can achieve a reasonably good effluent quality, further process optimization is hampered by a lack of mechanistic understanding of the factors influencing nitrogen removal, notably when it comes to mainstream anaerobically treated sewage. In this study, the factors that control the performance of SBTFs following anaerobic (i.e., UASB) reactors for sewage treatment were investigated. A demo-scale SBTF fed with anaerobically pre-treated sewage was monitored for 300 days, showing a median nitrification efficiency of 79% and a median total nitrogen removal efficiency of 26%. Heterotrophic denitrification was limited by the low organic carbon content of the anaerobic effluent. It was demonstrated that nitrification was impaired by a lack of inorganic carbon rather than by alkalinity limitation. To properly describe inorganic carbon limitation in models, bicarbonate was added as a state variable and sigmoidal kinetics were applied. The resulting model was able to capture the overall long-term experimental behaviour. There was no nitrite accumulation, which indicated that nitrite oxidizing bacteria were little or less affected by the inorganic carbon limitation. Overall, this study indicated the vital role of influent characteristics and operating conditions concerning nitrogen conversions in SBTFs treating anaerobic effluent, thus facilitating further process optimization.
厌氧污水处理是一种在温暖气候地区得到验证的技术，而海绵床滴滤器（SBTF）是去除残留有机碳和氮的重要后处理技术。尽管 SBTF 可以实现相当好的出水质量，但由于缺乏对影响氮去除的因素的机理理解，特别是在主流厌氧处理污水方面，进一步的工艺优化受到阻碍。在这项研究中，调查了控制 SBTF 在厌氧（即 UASB）反应器处理污水后的性能的因素。一个示范规模的 SBTF 用厌氧预处理的污水进料，监测了 300 天，显示出 79%的硝化效率和 26%的总氮去除效率的中位数。异养反硝化受到厌氧出水有机物含量低的限制。结果表明，硝化受到无机碳缺乏的影响，而不是碱度限制。为了在模型中正确描述无机碳限制，将碳酸氢盐作为状态变量添加，并应用了 S 型动力学。所得模型能够捕获整个长期实验行为。没有亚硝酸盐积累，这表明亚硝酸盐氧化菌受无机碳限制的影响较小或不受影响。总的来说，这项研究表明了进水特性和操作条件在 SBTF 处理厌氧废水中对氮转化的重要作用，从而促进了进一步的工艺优化。
