School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Bioresour Technol. 2013 Sep;144:328-36. doi: 10.1016/j.biortech.2013.06.127. Epub 2013 Jul 5.
This study focused on the effect of predated sludge recycle on the contribution of extracellular polymeric substances (EPSs) and their subfractions to sludge aggregation in combined MBR system. It was observed that aggregation abilities of sludge samples were decreased by worm predation. Furthermore, worm predation enhanced the energy barriers and weakened the secondary energy minimum in the interaction energy profiles of slime, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). Further investigations demonstrated that the content decrease and structural change of different EPS fractions induced by worm predation may be the reason for the decreased aggregation of sludge. Concomitantly, the adsorption tests and atomic force microscopy observation confirmed that the worm predation decreased the adsorption of slime, LB-EPS and TB-EPS on membrane. This would indicate the worm predation could keep an optimum EPS level for which floc structure was maintained and the fouling propensity of mixed liquid was reduced.
本研究聚焦于捕食污泥循环对胞外聚合物（EPS）及其亚组分在组合 MBR 系统中对污泥聚集贡献的影响。研究发现，污泥样品的聚集能力因虫体捕食而降低。此外，虫体捕食增强了污泥、松散结合 EPS（LB-EPS）和紧密结合 EPS（TB-EPS）之间相互作用能谱中的能垒，削弱了二级能量最小值。进一步的研究表明，虫体捕食导致不同 EPS 组分的含量减少和结构变化，可能是污泥聚集减少的原因。同时，吸附实验和原子力显微镜观察证实，虫体捕食减少了污泥、LB-EPS 和 TB-EPS 在膜上的吸附。这表明虫体捕食可以保持最佳的 EPS 水平，从而维持絮体结构并降低混合液的污染倾向。
