Chen Wei, Gao Xiaohong, Xu Hang, Cai Yan, Cui Jianfeng
Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
College of Environment, Hohai University, Nanjing 210098, China.
Chemosphere. 2017 Mar;170:196-206. doi: 10.1016/j.chemosphere.2016.12.004. Epub 2016 Dec 9.
Extracellular polymeric substances (EPS) are high molecular weight polymers and play a significant role in floc stability, floc size, bioflocculation and sludge settleability. The destruction and reconstruction of EPS improve the performance of solid-water separation processes. In this study, the influence of combined ultrasound pretreatment and chemical re-flocculation on the spatial distribution and composition of EPS was examined. Settleability efficiency demonstrated that the optimal operating condition was an ultrasound pretreatment time of 15 min at pH 6. Sludge particles were greatly disintegrated and the protein-like substances were converted into smaller molecules after ultrasound treatment, and pH had important effects on solubilization and degradation of protein-like substances. The flocs of sludge water after addition of polyacrylamide were larger in size and denser in structure than those resulting from addition of polyaluminium chloride. However, polyaluminium chloride had a better capacity for degrading EPS, especially at a dosage of 1.2 g/g total suspended solids. The results of this research show that the combination of ultrasonication and chemical re-flocculation is effective in treating sludge water from a drinking water treatment plant.
胞外聚合物（EPS）是高分子量聚合物，在絮体稳定性、絮体大小、生物絮凝和污泥沉降性能方面发挥着重要作用。EPS的破坏和重建改善了固液分离过程的性能。在本研究中，考察了超声预处理和化学再絮凝联合作用对EPS空间分布和组成的影响。沉降效率表明，最佳操作条件是在pH值为6时超声预处理15分钟。超声处理后污泥颗粒大幅解体，类蛋白物质转化为小分子，pH值对类蛋白物质的溶解和降解有重要影响。添加聚丙烯酰胺后污泥水的絮体比添加聚合氯化铝后的絮体尺寸更大、结构更致密。然而，聚合氯化铝对EPS的降解能力更好，尤其是在投加量为1.2 g/g总悬浮固体时。本研究结果表明，超声处理和化学再絮凝相结合对处理饮用水处理厂的污泥水是有效的。
