活性污泥胞外聚合物的分层组分及溶解性微生物代谢产物的特性

Characteristics of the stratification components of extracellular polymeric substances and soluble microbial products in activated sludge

提取了活性污泥胞外聚合物(EPS)和溶解性微生物代谢产物(SMP),并按EPS的紧密程度对松散EPS、紧密EPS的分层组分以及SMP属性进行了分析鉴定.结果表明,以葡萄糖为基质时,松散EPS的主要组成是多糖,紧密EPS的主要组成是蛋白质,而SMP主要由腐殖质类物质构成.SMP、松散EPS、紧密EPS和总样EPS的三维荧光图谱显示其只有类色氨酸峰和类腐殖酸峰,其类腐殖酸峰主要是由生物代谢产生的腐殖质组成.大分子量腐殖质类物质在几种组分中均出现,但是具有腐殖质特性的分子量为8500 Da的组分会在SMP中大量生成,而具有腐殖质特性的分子量为400 Da的组分只存在于EPS的紧密层中,这与微生物对这3种物质的生物可利用性有关.

In this study, extracellular polymeric substances （EPS） and soluble microbial products （SMP） were extracted from the active sludge. According to the degree of EPS compactness, the characteristics of stratification to the loosely bound EPS（LB-EPS） and tightly bound EPS（TB-EPS） were analysed and the property of SMP was identified. The results show that, when the matrix was glucose, LB-EPS was mainly made up of polysaccharides, TB-EPS was mainly made up of proteins, and SMP was mainly made up of humic substances. The excitation-emission fluorescence matrix spectroscopy shows that SMP, LB-EPS, TB-EPS and Total EPS all displayed typtophan-like and humic-like peaks. Humic-like peak was made up of the humic substances from the biological metabolism.The high molecular weight humic substances appeared in all the compositions.The humic substances with a molecular weight of 8500Da were generated heavily in SMP, and the humic substances with molecular weight of 400Da only exist in TB-EPS.This size distribution relates to the utilizability of these three substances by the microbes.