Judd Simon, Odai Albert, Buzatu Pompilia, Qiblawey Hazim
Gas Processing Center, Qatar University, Doha, Qatar.
Cranfield Water Science Institute, Cranfield Univeristy, Cranfield, Bedford MK43 0AL, UK.
Membranes (Basel). 2018 Nov 10;8(4):104. doi: 10.3390/membranes8040104.
The impact of the application of mechanically-imposed shear on the propensity for fouling and clogging (or "sludging"-the agglomeration of sludge solids in the membrane channel) of an immersed flat sheet (iFS) membrane bioreactor (MBR) was studied. The bench-scale test cell used contained a single flat sheet fitted with a crank and motor to allow the membrane to be oscillated (or reciprocated) vertically at a low rate (20 RPM). The membrane was challenged with sludge samples from a local MBR installation treating petroleum industry effluent, the sludge having previously been demonstrated as having a high sludging propensity. Sludging was measured by direct visual observation of membrane surface occlusion by the agglomerated solids, with fouling being notionally represented by the rate of transmembrane pressure increase. Results demonstrated membrane reciprocation to have a more beneficial impact on sludging amelioration than on suppressing fouling. Compared with the stationary membrane, sludging was reduced by an average of 45% compared with only 13% for fouling suppression at the reference flux of 15 L·m·h applied. The specific energy demand of the mechanical shear application was calculated as being around 0.0081 kWh·m, significantly lower than values reported from a recent pilot scale study on a reciprocated immersed hollow fibre MBR. Whilst results appear promising in terms of energy efficiency, it is likely that the mechanical complexity of applying membrane movement would limit the practical application to low flows, and a correspondingly small number of membrane modules.
研究了施加机械剪切对浸没式平板（iFS）膜生物反应器（MBR）结垢和堵塞倾向（或“污泥聚集”——膜通道中污泥固体的团聚）的影响。所使用的实验室规模测试单元包含一块装有曲柄和电机的平板，以使膜能够以低速率（20转/分钟）垂直振荡（或往复运动）。用来自当地处理石油工业废水的MBR装置的污泥样品对膜进行挑战，该污泥先前已被证明具有高污泥聚集倾向。通过直接目视观察团聚固体对膜表面的堵塞来测量污泥聚集，污垢则通过跨膜压力增加速率来大致表示。结果表明，膜的往复运动对改善污泥聚集的影响比对抑制污垢的影响更有益。与固定膜相比，在施加的参考通量为15 L·m⁻²·h⁻¹时，污泥聚集减少了平均45%，而污垢抑制仅为13%。计算得出施加机械剪切的比能量需求约为0.0081 kWh·m⁻²，明显低于最近对往复式浸没中空纤维MBR进行的中试规模研究报告的值。虽然就能源效率而言结果似乎很有前景，但施加膜运动的机械复杂性可能会将实际应用限制在低流量以及相应较少数量的膜组件上。
