Department of Civil, Geological and Mining Engineering, Ecole Polytechnique of Montreal, P.O. Box 6079, Station centre-ville, Montreal, Quebec, Canada H3C 3A7.
Water Res. 2010 Apr;44(7):2179-88. doi: 10.1016/j.watres.2009.12.037. Epub 2010 Jan 4.
This study evaluated the potential biodegradability of the endogenous residue in activated sludge subjected to batch digestion under either non-aerated or alternating aerated and non-aerated conditions. Mixed liquor for the tests was generated in a 200 L pilot-scale aerobic membrane bioreactor (MBR) operated at a 5.2 days SRT. The MBR system was fed a soluble and completely biodegradable synthetic influent composed of sodium acetate as the sole carbon source. This influent, which contained no influent unbiodegradable organic or inorganic materials, allowed to generate sludge composed of essentially two fractions: a heterotrophic biomass X(H) and an endogenous residue X(E), the nitrifying biomass being negligible (less than 2%). The endogenous decay rate and the active biomass fraction of the MBR sludge were determined in 21-day aerobic digestion batch tests by monitoring the VSS and OUR responses. Fractions of X(H) and X(E): 68% and 32% were obtained, respectively, at a 5.2 days SRT. To assess the biodegradability of X(E), two batch digestion units operated at 35 degrees C were run for 90 days using thickened sludge from the MBR system. In the first unit, anaerobic conditions were maintained while in the second unit, alternating aerated and non-aerated conditions were applied. Data for both units showed apparent partial biodegradation of the endogenous residue. Modeling the batch tests indicated endogenous residue decay rates of 0.005 d(-1) and 0.012 d(-1) for the anaerobic unit and the alternating aerated and non-aerated conditions, respectively.
本研究评估了在非曝气或交替曝气和非曝气条件下进行批量消化时，活性污泥中内源性残留物质的潜在生物降解性。用于测试的混合液是在一个 200L 的中试规模好氧膜生物反应器（MBR）中产生的，该反应器的 SRT 为 5.2 天。MBR 系统以乙酸钠作为唯一碳源的可溶性和完全可生物降解的合成进水为进料。该进水不含不可生物降解的有机或无机材料，允许生成基本上由两个部分组成的污泥：异养生物量 X(H)和内源性残留物质 X(E)，硝化生物量可以忽略不计（小于 2%）。通过监测 VSS 和 OUR 响应，在 21 天的好氧消化批量测试中确定了 MBR 污泥的内源性衰减率和活性生物量分数。在 5.2 天 SRT 下，分别获得了 X(H)和 X(E)的分数：68%和 32%。为了评估 X(E)的生物降解性，使用来自 MBR 系统的浓缩污泥在 35°C 下运行了两个批量消化单元 90 天。在第一个单元中，保持厌氧条件，而在第二个单元中，采用交替曝气和非曝气条件。两个单元的数据都表明内源性残留物质有明显的部分生物降解。批量测试的模型表明，厌氧单元和交替曝气和非曝气条件下的内源性残留物质衰减率分别为 0.005 d(-1)和 0.012 d(-1)。
