Krause S, Cornel P, Wagner M
Darmstadt University of Technology, Institute WAR, Wastewater 64287 Darmstadt, Germany.
Water Sci Technol. 2003;47(12):169-76.
Membrane bioreactors (MBRs) for wastewater treatment offer the advantage of a complete removal of solids from the effluent. The secondary clarifier is replaced by a membrane filtration and therefore high biomass concentrations (MLSS) in the reactor are possible. The design of the aeration system is vital for an energy efficient operation of any wastewater treatment plant. Hence the exact measurement of oxygen transfer rates (OTR) and alpha-values is important. For MBRs these values reported in literature differ considerably. The OTR can be measured using non-steady state methods or using the off-gas method. The non-steady state methods additionally require the determination of the respiration rate (oxygen uptake rate OUR), which usually is measured in lab scale units. As there are differences of OUR between lab scale and full scale measurements, off-gas tests (which do not require an additional respiration test) were performed in order to compare both methods at high MLSS concentrations. Both methods result in the same average value of OTR. Due to variations in loading and wastewater composition variations of OTR in time can be pointed out using the off-gas method. For the first time a comparison of different oxygen transfer tests in full scale membrane bioreactors is presented.
用于废水处理的膜生物反应器（MBR）具有从流出物中完全去除固体的优点。二次沉淀池被膜过滤所取代，因此反应器中可以实现高生物量浓度（MLSS）。曝气系统的设计对于任何废水处理厂的节能运行至关重要。因此，准确测量氧传递速率（OTR）和α值很重要。对于MBR，文献中报道的这些值差异很大。OTR可以使用非稳态方法或尾气法进行测量。非稳态方法还需要测定呼吸速率（氧吸收速率OUR），通常在实验室规模的装置中进行测量。由于实验室规模和全尺寸测量之间OUR存在差异，因此进行了尾气测试（不需要额外的呼吸测试），以便在高MLSS浓度下比较这两种方法。两种方法得出的OTR平均值相同。由于负荷和废水成分的变化，可以使用尾气法指出OTR随时间的变化。首次对全尺寸膜生物反应器中不同的氧传递测试进行了比较。
