Effect of cyclic aeration on fouling in submerged membrane bioreactor for wastewater treatment
- 作者：Jun Wu ; j.wu@yzu.edu.cn ; Chengda He
- 关键词：Membrane fouling ; Cyclic aeration ; Floc size distribution ; Particle size distribution ; Reversible fouling ; Irreversible fouling
- 刊名：Water Research
- 出版年：2012
- 期刊代码：57_00431354
- 类别：civ
- 出版时间：July, 2012
- 卷：46
- 期：11
- 页码：3507-3515
- 文件大小：525 K
摘要
Due to the inefficiency of aeration measures in preventing fouling by soluble and colloidal particles. The effect of alternating high/low cyclic aeration mode on the membrane fouling in the submerged membrane bioreactor was studied by comparing to fouling in a constant aeration mode. Results indicated a higher overall fouling rate in the cyclic aeration mode than in the constant aeration. However, a higher percentage of reversible fouling was observed for the cyclic aeration mode. The membrane permeability can be more easily recovered from physical cleaning such as backwashing in the cyclic aeration mode. The activated sludge floc size distribution analysis revealed a floc destruction and re-flocculation processes caused by the alternating high/low aeration. The short high aeration period could prevent the destruction of strong strength bonds within activated sludge flocs. Therefore, less soluble and colloidal material was observed in the supernatant due to the preservation of the strong strength bonds. The weak strength bonds damaged in the high aeration period could be recovered in the re-flocculation process in the low aeration period. The floc destruction and re-flocculation processes were suggested to be the main reason for the low irreversible fouling in the cyclic aeration mode.