Fouling characterisation in membrane bioreactors
Fouling characterisation in membrane bioreactors
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DOI：
10.1016/s1383-5866(00)00156-8
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发表时间：
2001-03-01
影响因子：
8.6
通讯作者：
Buisson, H
中科院分区：
文献类型：
--
作者：
Bouhabila, E;Ben Aïm, R;Buisson, H
与传统的污水处理工艺相比，膜生物反应器具有生物降解效率高、污泥产量少、结构紧凑等优点。然而，膜污染是该工艺快速发展的主要限制。使用中空纤维（孔径为0.1 μ m）浸没在曝气池中处理代表乳品废水的合成废水进行了实验研究。在相同的有机负荷（5.7kgCOD/m3/d）下，比较了3个反应器在不同泥龄（10、20和30 d）下的COD去除率、污泥产量和污染能力。COD去除率高：95- 97.5%。污泥产率随泥龄从10天增加到30天而从0.31 kg MLSS/kg COD下降到0.16 kg MLSS/kg COD。针对污泥的污染能力，设计了一个具体的实验（过滤过程中的比阻和水力阻力的测量），以确定污泥的三个部分：悬浮固体，胶体和溶质对膜污染的影响。所有的实验都证实了间隙物质-胶体和溶质-在膜污染中的重要性。因此，可以预期鼓泡仅部分有效，因为气泡对于限制颗粒沉积和极化现象是有效的，但对于内部结垢不是有效的。将空气流速从每小时1.2 m（3）/m（2个膜面积）增加到3.6 m（3）/m（2个膜面积），可以降低总阻力-从而增加滤液通量-比率为3。然而，对于给定的曝气条件，定期反冲洗通过减少内部污垢而具有额外的效率。在最佳反冲洗条件下（每5 min反冲洗15 s），阻力可降低3.5倍。(C)2001 Elsevier Science B. V.保留所有权利。
Compared with conventional wastewater treatment processes, membrane bioreactors offer several advantages, e.g. high biodegradation efficiency, smaller sludge production and compactness. However, membrane fouling is the main limitation to faster development of this process. An experimental study has been performed using hollow fibers (pore size 0.1 mum) immersed in an aerated tank for treating synthetic wastewater representative of dairy effluent. For the same organic load (5.7 kg COD/m(3) per day) the COD removal efficiency, the sludge production and fouling ability were compared in three reactors operated at different sludge ages (10, 20 and 30 days). COD removal was high: 95-97.5%. The sludge production decreased from 0.31 to 0.16 kg MLSS/kg CODremoved when the sludge age increased from 10 to 30 days. Concerning the fouling ability of the sludge, a specific experiment (measurement of the specific resistance and hydraulic resistance during filtration) was designed to determine the influence on membrane fouling of the three fractions of the sludge: suspended solids, colloids and solutes. All the experiments confirm the importance of the interstitial matter - colloids and solutes - in membrane fouling. Consecluently, bubbling can be expected to be only partially efficient, as bubbles are efficient for limiting particle deposition and polarisation phenomena, but not for internal fouling. Increasing the air flow rate from 1.2 to 3.6 m(3)/m(2membrane area) per hour, it was possible to decrease the total resistance - thus increasing the filtrate flux - by a ratio of 3. However, for given conditions of aeration, periodic backwashing rave an additional efficiency by decreasing internal fouling. In optimal conditions of backwashing (15 s every 5 min) the resistance could be decreased by 3.5-fold. (C) 2001 Elsevier Science B.V. All rights reserved.