自养、异养和混合营养污泥沉降性能差异原因探讨

本研究建立了3个有效容积为4.2L的有机玻璃材料反应器,培养驯化自养、异养和混合营养3种不同营养类型的活性污泥.通过分析3种不同营养类型污泥沉降性能的差异,旨在找出造成3种污泥沉降性能差异的微观原因,为改善污泥的沉降性能提供新的途径和理论依据.研究结果表明,自养污泥沉降性能最好,混合营养污泥次之,异养污泥最差;污泥的粒径对沉降性能无明显影响;Zeta电位和相对疏水性是造成3种污泥沉降性能差异的重要表面理化性质,Zeta电位值越接近于0,相对疏水性越强,污泥沉降性能越好;污泥胞外聚合物(EPS)中腐殖酸和多糖含量对污泥表面Zeta电位、相对疏水性和污泥沉降性能无明显影响;EPS中蛋白质含量直接影响Zeta电位值,进而造成3种污泥污泥沉降性能差异;而EPS总量和3种污泥沉降性能没有明显相关性.

Investigation of the reasons for settleability differences among autotrophic,heterotrophic and mixed nutritional sludges

In order to cultivate three different nutritive types of sludge,three 4.2L Plexiglas reactor was fabricated in this research. This study aimed to find out the micro reasons of the settleability differences among three different nutritive types of sludges(autotrophic,heterotrophic and mixed nutritional sludge). The results showed that the settleability of different sludge were in the following order:autotrophic sludge >mixed nutritional sludge >heterotrophic sludge. Particle size had no obvious effects on settleability. Zeta potential and sludge hydrophobicity were the most important surface physicochemical property. The Zeta potential value was closer to zero,the better settleability for the sludge was achieved. Humic Acid and polysaccharide concentration in sludge EPS had no significant effects on the Zeta potential,sludge hydrophobicity and sludge settleability. Protein affected sludge settleability by directly changing the Zeta potential values and sludge hydrophobicity. In addition,the total amount of EPS had insignificant effects on the sludge settleability.