中文摘要：

以消化污泥为研究对象,研究了Fe^2＋浓度、pH和离子强度等因素对Fe^2＋促进消化污泥凝聚性能的影响,采用扩展的DLVO理论（EDLVO）探讨了污泥絮体凝聚过程中结合能的变化特征,并对典型条件下各层胞外聚合物（EPS）的三维荧光谱图（EEM）进行了分析。结果表明：Fe^2＋促进消化污泥凝聚的最佳化学条件为Fe^2＋浓度50 mmol·L^-1,pH=7.57（原始值）,离子强度0.01 mol·L^-1。在最佳Fe^2＋浓度或pH下,Fe^2＋促进污泥凝聚的主要作用为：增大Zeta电位、提高絮体粒径和密实程度、增强疏水性和降低污泥絮体间的能垒;在最佳离子强度下,提高絮体粒径和密实程度是促进污泥凝聚的主要作用;离子强度的增加并未降低污泥位能曲线的能垒。EEM证明,Fe^2＋主要与污泥EPS中slime层结合以促进污泥凝聚,主要结合物为蛋白质A、可见富里酸和紫外富里酸。

英文摘要：

In this study,the effects of Fe^2＋concentration,pH and ionic strength on the promoting aggregation of digested sludge（DS） by Fe^2＋were investigated,and the extended DLVO（EDLVO） theory was used to reveal the variation characteristics of binding energy among sludge flocs during Fe^2＋promoting aggregation. The threelayered EPS extracted from typical DS sample was characterized by three-dimensional excitation emission matrix fluorescence spectroscopy（EEM）. The results showed that the optimum chemical conditions for Fe^2＋promoting aggregation were determined at Fe^2＋dosage of 50 mmol·L^-1,pH 7. 57 for raw DS,and ionic strength of 0. 01mol·L^-1,respectively. Under the optimal Fe^2＋concentration or pH,Fe^2＋promoting aggregation of DS was ascribed to the increase of the Zeta potential,size and compactness,as well as the hydrophobicity of DS flocs,and the reduction in the energy barrier among DS flocs. However,at the optimal ionic strength,Fe^2＋promoting aggregation was attributed to increasing the size and compactness of DS flocs. The increase of ionic strength could not result in the decrease of the energy barrier among DS flocs. EEMs of three-layered EPS extracted from typical DS sample indicated that the combination between Fe^2＋and slime was the main approach to promote aggregation of DS,and the corresponding slime components were protein A,UV-visible fulvic acid and fulvic acid.