为了解不同生物营养物处理(BNR)工艺剩余污泥性质差异及其中温水解特性,采用序批式实验研究了来源于Orbal氧化沟(OD)和倒置A2/O工艺剩余污泥在中温水解过程中污泥浓度、营养物释放、污泥粒径、污泥絮凝性、污泥比阻及污泥胞外聚合物(EPS)的历时变化。结果表明,相同泥龄(约18d)条件下,OrbalOD剩余污泥氮含量较高,倒置A2/O剩余污泥磷含量较高,两者VSS/SS均低于0.6,导致中温水解过程污泥减量空间有限、氮磷释放速率不同。此外,尽管倒置A2/O工艺剩余污泥絮体尺寸及絮凝能力明显大于OrbalOD工艺剩余污泥的对应值,但两污泥比阻相近。中温水解过程中,两污泥絮体的尺寸均变小、絮凝能力均降低、比阻均增高;两者的胞外聚合物均呈现增高再降低趋势,且蛋白质均占EPS质量的75%以上,为主要的胞外物质。
A batch experiment was carried out to study the mesophilic hydrolysis of waste sludge from an Orbal oxidation ditch(OD) and an inverted A2/O, which belonged to biological nutrient removal sludge and had a similar SRT (approximately 18 days). The variances of sludge concentration, nutrient release, floc size, floc- culating ability, specific resistance and extracellular polymeric substances (EPS) of both were analyzed. The mesophilic hydrolysis results exhibited that the reduction of BNR sludge was little because the ratio of VSS to TSS was below 0.6 for both sludge. Meanwhile, the release rate of nitrogen and phosphorus was different because ni- trogen content was higher but phosphorus content was lower in Orbal OD sludge than that in inverted A2/O sludge. In addition, the floc size and flocculating ability of sludge from inverted A2/O was higher than that of sludge from Orbal OD, and the above parameters for both were dropping with time. However, both sludge had a similar specific resistance which was increasing with hydrolysis time. As for EPS of the sludge, both appeared to increase and then decrease during mesophilic hydrolysis and protein was the dominant substance, occupying more than 75% of EPS for both.