碳氮比对活性污泥胞外聚合物的长期影响

Effect of C/N ratio on extracellular polymeric substance(EPS) in the sequencing batch reactor(SBR)

以人工模拟废水为研究对象,采用4组SBR反应器(R0,R5,R10和R15),重点考察了碳氮比(C/N)对胞外聚合物(EPS)含量及其组分(蛋白质(PN)、多糖(PS)和核酸(DNA))的影响.试验结果表明:C/N对EPS及其组分具有显著影响.随着C/N由0升高至15,EPS和紧密结合型胞外聚合物(TB-EPS)含量逐渐升高,而松散型胞外聚合物(LB-EPS)含量逐渐降低,EPS以TB-EPS为主(占77.4%~93.6%).EPS和TB-EPS中的PN、PS和DNA含量随着C/N值升高而升高,LB-EPS中的PN、PS和DNA含量随C/N升高而降低.此外,随着C/N的增大,毛细吸水时间(CST)和污泥比阻(SRF)值显著增大,污泥的脱水性能变差.

In this paper, the long-term effect of C/N ratio on extracellular polymeric substance （EPS） in the sequencingbatch reactor （SBR） treating synthetic wastewater was investigated under four C/N ratio conditions （0, 5, 10, 15）. Theresults showed that the C/N ratio had a significant impact on EPS and its composition. With the increase of C/N ratio（0→5→10→15）, EPS and tightly bound EPS （TB-EPS） content increased, while, loosely bound EPS （LB-EPS） decreasedslowly. TB-EPS was dominant in EPS （the percentage of TB-EPS/EPS was 77.4-93.6%）. Moreover, protein （PN）,Carbohydrate （PS） and DNA in EPS and TB-EPS increased with the C/N ratio increasing. PN, PS and DNA in LB-EPSdecreased as the C/N ratio increased. Moreover, capillary suction times （CST） and specific resistance to filtration （SRF）increased when the C/N ratio increased, and caused deterioration in sludge dewaterability.