好氧污泥颗粒化过程中Zeta电位与EPS的变化特性

研究了好氧颗粒污泥在形成过程中Zeta电位、胞外多聚物的变化以及两者之间的关系.通过对污泥调控生长,形成完全颗粒化的好氧污泥.在好氧颗粒形成过程中,污泥的Zeta电位由接种时的-19.1 mV逐渐降至-10.1 mV.完全颗粒化以后,成熟后的好氧颗粒污泥Zeta电位稳定维持在-10 mV左右,说明维持污泥较低的Zeta电位是好氧颗粒污泥形成的重要条件.颗粒化过程中污泥EPS中多糖含量基本不变,蛋白含量增加明显,从13.65 mg.g-1增加到54.12 mg.g-1,蛋白/多糖比值从0.67增加到3.31;污泥的Zeta电位与蛋白/多糖的比值呈正相关,相关系数为0.849,这些结果说明蛋白质对降低污泥表面电位,促进污泥聚集以及好氧颗粒污泥的形成生长等可能起着重要作用.

Profiles of Zeta Potential and EPS in Granulation Process of Aerobic Sludge

The profiles of Zeta potential and EPS, and their correlation were investigated for the aerobic sludge during granulation process. The complete aerobic granular particles were cultivated and grew by controlling operational conditions. During the granulation process, Zeta potential of sludge was decreased from -19.1 mV to -10.1 mV gradually. And it was maintained at a low level-about -10 mV in matured granules, which indicated a low Zeta potential of sludge is an important factor for the development of aerobic granulation of sludge. There was no big variation of polysaccharide in EPS during the granulation, but the protein of EPS was significantly increased, from 13.65 mg·g^-1 to 54.12 mg·g^-1. The protein/polysaccharide ratio was went up from 0.67 to 3.31.There existed a good correlation between PN/PS ratio and Zeta potential, coefficient 0.849.These results demonstrated the protein of EPS played a significant role on decrease of surface electronic potential, stimulating the growth of sludge aggregation and the formation the aerobic granular sludge.