Ca^(2+)、Mg^(2+)对好氧污泥颗粒化的影响研究

Research on the influences of Ca^(2+),Mg^(2+) on aerobic sludge granulation

研究了投加不同金属离子(Ca2+、Mg2+)在好氧污泥颗粒化过程中的作用,简要分析了颗粒形成过程中污泥的形态和物化性质变化,重点探究Zeta电位、胞外多聚物(EPS)的变化以及两者之间的关系。在接种普通活性污泥的2个序批式反应器中分别投加等量40 mg/L的Ca2+和Mg2+,培养运行34 d,2个反应器都已全部颗粒化,结果显示添加Mg2+更有利于缩短好氧颗粒污泥系统的启动时间,而添加Ca2+形成的颗粒污泥平均粒径较小,添加Mg2+更能促进EPS的分泌。底物匮乏期,添加Mg2+较添加Ca2+的微生物更易利用EPS作为碳源,且在饱食-饥饿期的交替阶段Mg2+对污泥表面Zeta电位造成的影响更大。

The effect of adding different kinds of metallic ions （Ca^2＋, Mg^2＋） on aerobic sludge granulation process has been studied. The shape of sludge and the change of physical ＆ chemical properties in the course of formation are analyzed briefly. The Zeta potentials, extraeellular polymeric substances （EPS）, and the relationship between the two of them are probed into emphatically. By adding equal amount, 40 mg/L of Ca^2＋ and Mg^2＋ to the two sequencing batch reactors for inoculating ordinary activated sludge and by culturing in operation for 34 days ,the two reactors have all completed the granulation. The results show that adding Mg^2＋ is more advantageous to the shortening of time for the start-up of aerobic granular sludge system. However, the granular sludge formed by adding Ca〉 has smaller granular sizes averagely. Adding Mg^2＋ can promote the secretion of EPS. During the substrate deprivation period, adding Mg^2＋ is more apt to use EPS as carbon source than adding Ca^2＋. Furthermore,in the alterative stage of satiation- starvation, Mg^2＋ causes greater effect on Zeta potential of the sludge surface.