COD质量浓度和水流剪切力对胞外聚合物分泌的影响(英文)  

Effect of COD concentration and shear stress on secretion of extracellular polymeric substances

作　　者：祁佩时[1] 王文斌[1] 王弘宇[2] 李正[1] 綦峥[1] 

机构地区：[1]哈尔滨工业大学市政环境工程学院,哈尔滨150090 [2]武汉大学市政工程系,武汉430070

出　　处：《哈尔滨商业大学学报（自然科学版）》2008年第6期682-686,762,共6页Journal of Harbin University of Commerce：Natural Sciences Edition

摘　　要：试验使用悬浮载体生物膜反应器,研究了COD质量浓度和水流剪切力对生物膜上中胞外多糖和胞外蛋白的影响.结果表明,胞外多糖和胞外蛋白的分泌量随着进水COD质量浓度的波动而变化,基质质量浓度的增加使生物膜上EPS的分泌增多.水流速度的提高促进了水流剪切力的增加;当水流速度从0.032 m/s,增加到0.056 m/s,然后在增加到0.089 m/s时,水流剪切力的提高促进了胞外多糖的分泌,微生物在经历一个短暂的适应阶段后胞外多糖的分泌量开始升高.生物膜重新形成和达到稳定后胞外多糖的分泌量又逐渐回落到一个稳定的水平.回落所用时间的长短和水流剪切力的大小有关.水流剪切力越大,回复所用的时间越长.水流剪切力的增加对胞外蛋白的影响较小.高的水流剪切力能够引起更多的生物膜脱落.The effect of COD concentration and shear stress on the EPS secretion is investigated in a suspended carrier biofllm reactor. High influent COD concentration yielded higher EPS secretion and lower COD concentration caused the EPS secretion to drop accordingly. The secretion of EPS - protein and EPS - polysaccharides by the microorganism seems to be a direct function of the influent COD concentration. The increase of shear stress on the biofilm enhanced the EPS -polysaccharides secretion after an acclimation period. As the structure of biofilm reestablished and reached a steady state again, the EPS - polysaccharides secretion dropped down and stayed at a value which approximated to the volume before the change occurred. The microorganism takes longer to acclimate to higher shear stress. When the shear stress increases from 0. 032 m/s to 0.056m/s, then to 0. 089 m/s, the EPS - protein secretion is fluctuated in a small range of 4.3 - 5.1 mg/g MLSS and 4.1 - 5.4 mg/g MLSS, respectively. It is also observed that more erosion of the biofilm occurred when the shear stress was increased.

关 键 词：生物膜 水力剪切力 胞外聚合物(EPS) 悬浮载体 

分 类 号：X703[环境科学与工程—环境工程]