好氧颗粒污泥胞外聚合物的产生及其分布

PRODUCTION OF EXTRACELLULAR POLYMERIC SUBSTANCES FROM AEROBIC GRANULAR SLUDGE AND ITS DISTRIBUTION

考察了不同操作条件和基质条件对好氧颗粒污泥中胞外聚合物(EPS)产生的影响及其在污泥和体系上清液中的分布.结果表明:随体系操作条件和基质条件的变化,好氧颗粒污泥内部和上清液中的EPS含量呈规律性变化.相对而言,好氧颗粒污泥中EPS含量的变化幅度较小,过多的EPS则释放到上清液中.大量EPS的释放只发生在颗粒污泥解体时,而酸性条件和不适当的C/N比不利于好氧颗粒污泥的形成及形态保持.体系溶解氧为4.5 mg.l-1,pH为中性,污泥负荷小于等于0.37kgCOD.kg-1MLSS.d-1,碳氮比为20∶1时,好氧颗粒污泥中EPS的含量约占污泥总质量的9%—12%,与厌氧颗粒污泥(0.6%—20%)相近,但远低于絮状活性污泥(80%),此时,EPS在上清液中的含量最低或接近最低,为14—26mg.l-1.

The effect of operating and nutrition conditions on the mass of extracellular polymeric substances （EPS） produced by aerobic granular sludge and its distribution between sludge and supematant was investigated in the present paper. The results showed that the changes of EPS content produced and its distridution were regular with the operating and nutrition conditions. The amount of EPS in sludge was relatively stable and the excessive EPS would be released into the supernatant. Moreover, a large amount of EPS was produced only when the aerobic sludge granular broke. pH value and C/N ratio had bad effect on the granulation of sludge. Under the conditions of 4.5mg · l^-1 DO, 7.0 pH value, 0. 37kgCOD · kg^-1 MLSS · d^-1 sludge loading and 20：1 C/N ratio, the content of EPS in aerobic granular sludge was around 9%-12%, which fell into 0. 6%-20% of anaerobic granular sludge and much lower than 80% of aerobic floc sludge, and the concentration of EPS in supernatant amounted to the lowest with 14-26mg · l^-1.