Turan M, Ozturk I
Istanbul Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, 80626 Maslak, Istanbul, Turkey.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2001;36(6):1041-53. doi: 10.1081/ese-100104130.
Bed expansion characteristics and predicting biofilm development and biomass hold-up in the anaerobic fluidized bed reactor were investigated. The treatability studies of brewery wastes were carried out in a pilot-scale fluidized bed reactor for a nine months period. The expansion and particle mixing characteristics of a fluidized bed containing different bioparticles is a complicated function of many variables, including hydrodynamics, support characteristics, and biofilm structures. The biological fluidized bed reactors have two types of bed expansion; the first is due to an increase of the superficial velocity and the second is due to the microbial growth in the bed. A new relationship for the porosity of the biological fluidized beds, was developed. Biofilm thickness and bed porosity increased rapidly in the upper part of the bed and the bioparticles become lighter than the clean particles with decreasing effective density. Most bioparticles in the anaerobic fluidized bed reactor (AFBR) were ellipsoidal and the geometric mean diameters were considered as the characteristic diameter. Their surface roughness causes an increase in the drag force acting on the particle. Thus, the expansion coefficient increased from 3.44 to 3.64 as terminal settling velocity decreased from 6.99 to 4.29 cm/s. An almost linear relationship was observed between local porosity and biofilm thickness. The differences between the measured and calculated biomass concentrations varied in the range of 0.4 and 12% (average 4.6%) considering the results from the pilot-scale AFBR. The bed expansion rate of the AFBR, varied from 12.3 to 18.3% whereas, the expansion rate of the clean bed also found between 7.9 and 12.7%. Consequently, the bed expansion rate due to biofilm accumulation on the particles can be well described to vary between 4.4 and 5.6%.
研究了厌氧流化床反应器中的床层膨胀特性，并预测了生物膜的形成和生物量的滞留情况。在中试规模的流化床反应器中，对啤酒厂废水进行了为期九个月的可处理性研究。含有不同生物颗粒的流化床的膨胀和颗粒混合特性是许多变量的复杂函数，包括流体动力学、载体特性和生物膜结构。生物流化床反应器有两种床层膨胀类型：第一种是由于表观流速增加，第二种是由于床层中微生物的生长。建立了生物流化床孔隙率的新关系。床层上部的生物膜厚度和床层孔隙率迅速增加，随着有效密度的降低，生物颗粒变得比清洁颗粒更轻。厌氧流化床反应器（AFBR）中的大多数生物颗粒呈椭圆形，几何平均直径被视为特征直径。它们的表面粗糙度导致作用在颗粒上的曳力增加。因此，随着终端沉降速度从6.99厘米/秒降至4.29厘米/秒，膨胀系数从3.44增加到3.64。观察到局部孔隙率与生物膜厚度之间几乎呈线性关系。考虑到中试规模AFBR的结果，实测生物量浓度与计算生物量浓度之间的差异在0.4%至12%（平均4.6%）范围内变化。AFBR的床层膨胀率在12.3%至18.3%之间变化，而清洁床层的膨胀率也在7.9%至12.7%之间。因此，可以很好地描述由于颗粒上生物膜积累导致的床层膨胀率在4.4%至5.6%之间变化。
