Sub-Department of Environmental Technology, Wageningen University, Wageningen, Netherlands.
Water Environ Res. 2009 Nov;81(11):2372-80. doi: 10.2175/106143009x426040.
Anaerobic biomass retention under thermophilic conditions has proven difficult. Membrane filtration can be used as alternative way to achieve high sludge concentrations. This research studied the feasibility of anaerobic membrane bioreactors (AnMBRs) under thermophilic conditions. A sidestream MBR was operated at crossflow velocities up to 1.5 m/s. For comparison, a thermophilic upflow sludge blanket reactor also was operated. Results confirmed that biomass retention may limit the performance of sludge bed reactors during long-term operation. During MBR operation, cake formation was identified as the key factor limiting the applicable flux. Low levels of irreversible fouling were observed. Even though high shear can provide an increase in particle back-transport, exposure of the sludge to a high shear stress produced a reduction of particle size, affecting the attainable flux. The concept of "shear rate dilemma" is introduced to describe this dual effect of shear during the operation of MBRs.
在高温条件下，厌氧菌生物量的保留被证明是困难的。膜过滤可以作为实现高污泥浓度的替代方法。本研究研究了在高温条件下厌氧膜生物反应器（AnMBRs）的可行性。侧流 MBR 在高达 1.5 m/s 的错流速度下运行。为了进行比较，还运行了一个高温上流污泥床反应器。结果证实，在长期运行过程中，生物量保留可能会限制污泥床反应器的性能。在 MBR 运行过程中，滤饼形成被确定为限制适用通量的关键因素。观察到低水平的不可逆污染。尽管高剪切力可以提供颗粒反向输送的增加，但将污泥暴露于高剪切应力会导致颗粒尺寸减小，从而影响可达到的通量。“剪切速率困境”的概念被引入来描述 MBR 运行过程中剪切的这种双重作用。
