Faculty of Civil and Environmental Engineering, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland E-mail:
Water Sci Technol. 2014;69(6):1136-44. doi: 10.2166/wst.2013.771.
The hydrolysis process of slowly biodegradable substrate (XS) has an impact on the efficiencies of nutrient removal in activated sludge systems. Measurement of oxygen utilization rates (OURs) and corresponding chemical oxygen demand (COD) is accepted as a very useful tool to reflect the consumption of biodegradable substrates. The influence of the SS fraction in biological wastewater treatment systems has been extensively investigated, but little information is known about the effects of XS on OUR. The aim of this study was to determine the immediate effects of particulate and colloidal (XS) biodegradable compounds on oxygen utilization for a full-scale process mixed liquor from a large wastewater treatment plant located in northern Poland. Since it is difficult to distinguish XS in a direct way, a novel procedure, based on the standard batch tests, was developed and run in parallel reactors with settled wastewater (SWW) and pretreated SWW samples. Two types of aerobic OUR experiments with low and high substrate/biomass (S0/X0 ratio) concentration, were carried out with the SWW without pretreatment, and pretreated with a coagulation-flocculation (C-F) method. The removal of colloidal and particulate fractions by C-F resulted in reduced process rates. The major discrepancy in the rate reductions (over 300% referred to the OURmax) was observed during the OUR batch test with high S0/X0 ratio.
缓慢生物降解底物（XS）的水解过程会影响活性污泥系统中营养物质去除的效率。测量耗氧速率（OURs）和相应的化学需氧量（COD）被认为是反映可生物降解底物消耗的非常有用的工具。生物废水处理系统中 SS 分数的影响已经得到了广泛的研究，但关于 XS 对 OUR 的影响知之甚少。本研究的目的是确定来自波兰北部大型污水处理厂的全规模工艺混合液中颗粒状和胶体（XS）可生物降解化合物对耗氧的直接影响。由于难以直接区分 XS，因此开发了一种基于标准批处理测试的新程序，并在具有沉降废水（SWW）和预处理的 SWW 样品的平行反应器中运行。用未经预处理和用混凝-絮凝（C-F）方法预处理的 SWW 进行了两种低和高底物/生物量（S0/X0 比）浓度的好氧 OUR 实验。C-F 对胶体和颗粒部分的去除导致处理速率降低。在高 S0/X0 比的 OUR 批处理测试中，观察到速率降低的主要差异（相对于 OURmax 超过 300%）。
