摘要
为减小微生物絮体对膜的污染 ,设计了一种具有沉降室的膜生物反应器 ,膜A与膜B分别淹没在上清液和污泥混合液中以相同的抽吸方式运行 .与预期结果相反 ,膜A比膜B的污染速度还快 .为探讨膜污染机理 ,考察了污泥混合液中不同组分对膜污染的影响 ,利用扫描电镜和原子力显微镜分析了膜面污染层的特征 .结果发现 ,在污泥混合液与上清液中膜面污染层在微观结构上存在显著差异 ,其方差平均粗糙度Rms分别为 13 2 3nm和 75 2nm .经膜污染机理分析认为 :微生物絮体和大分子有机物会在膜面形成污染层 ,该污染层作为“二次膜”影响膜过滤性能 .上清液中细小的微生物絮体和大分子有机物形成的污染层相对致密 。
A special membrane bioreactor was designed which had a settlement tank in order to remove the microbial flocs and reduce the membrane fouling. The membrane A and membrane B were submerged in the mixed activated sludge liquor and supernatant liquor, respectively. The two membrane modules were operated under the same suction condition. Unexpectedly, the fouling rate of membrane A was faster than that of membrane B. In order to investigate the mechanism of membrane fouling, effects of different components on membrane fouling were analyzed. In addition, the fouled layers were characterized by scanning electron microscopy and atomic force microscopy. It was found that the microstructures of the fouled layers formed in the mixed activated sludge liquor and supernatant liquor showed great differences. The square roughness Rms of the layers were 132.3nm and 75.2nm, respectively. According to the mechanism analysis, it was proposed that the microbial flocs as well as the macromolecular organic compounds could form a fouled layer as a “second membrane” on the membrane surface, which could impact the filterability of the membrane. In the supernatant liquor, the smaller flocs coupled with macromolecular organic compounds could form a more compact fouled layer and cause severer membrane fouling.
出处
《环境科学学报》
CAS
CSCD
北大核心
2005年第3期385-390,共6页
Acta Scientiae Circumstantiae
基金
高校优秀青年教师教学科研奖励计划
973国家重点研究发展计划 (编号 :2 0 0 4CB4185 0 5 )
