• 关键词：紧密结合胞外聚合物(TB-EPS)  高岭土  絮凝特性

• 基金项目：国家自然科学基金(No.50921064)

• 阮晓东
• 中国科学院生态环境研究中心,北京 100085

• 刘俊新
• 中国科学院生态环境研究中心,北京 100085

• 摘要：为了解活性污泥中紧密结合胞外聚合物(tightly bound extracellular polymeric substances,TB-EPS)的絮凝特性,采用激光粒度仪在线监测技术考察了TB-EPS与高岭土生成絮体的过程以及絮体的破碎与再凝聚规律.结果表明,TB-EPS的主要组分为蛋白质和多糖聚合物,增加TB-EPS的投加量,絮体的粒径相应增大,悬浊液的剩余浊度降低.随着絮体破碎-再凝聚次数的增加,絮体的破碎因子升高而恢复因子降低,表明TB-EPS形成的絮体的强度逐渐降低,同时再凝聚的能力也逐渐降低.TB-EPS吸附高岭土的主要作用力为氢键作用,但在絮体形成过程中多糖聚合物之间的纠缠作用和蛋白质成分之间的疏水作用也可能发挥一定的作用.絮体的破碎是侵蚀和破裂同时作用的结果.

• Abstract：To understand the flocculation characteristics of the tightly bound extracellular polymeric substances (TB-EPS) of activated sludge, the laser particle size analyzer on-line monitoring technique was employed to investigate the formation, breakup and regrowth process of the flocs formed by TB-EPS and kaolin. The results showed that the TB-EPS were mainly composed of proteins and polysaccharides. In response to an increased TB-EPS dosage, the size of the flocs increased while the residual turbidity of the suspension decreased. As the number of the breakup and regrowth cycle increased, the breakup factor (Bf) rose while the regrowth factor (Rf) dropped, indicating that both the adhesive strength and the regrowth ability of the flocs weakened gradually. Hydrogen bonding was the major driving force for the adsorption of kaolin by TB-EPS, but the entanglement among polysaccharide chains and the hydrophobic interaction among protein components may also play a role in the formation of flocs. The breakup of flocs was the result of the simultaneous action of erosion and fragmentation.

• Key words：TB-EPS  kaolin  flocculation characteristics

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