好氧颗粒污泥系统中溶解性微生物代谢产物的特征及主要组分

Characterization Composition of Soluble Microbial Products in an Aerobic Granular Sludge System

采用SBR反应器以絮状活性污泥为接种污泥培养好氧颗粒污泥,主要考察好氧颗粒污泥系统中溶解性微生物代谢产物(SMP)的产生、相对分子质量分布以及主要组成物质.结果表明SMP是出水COD的主要组分,浓度为71~85 mg·L-1,SMP的产生与微生物对基质的利用、微生物衰亡和胞外聚合物(EPS)的水解有关.相对分子质量分布表明大部分SMP相对分子质量小于3×103,所占比例为54.8%~71.7%,而相对分子质量大于100×103的组分只占总SMP的一小部分,所占比例为9.3%~14.5%.三维荧光光谱分析表明,出水SMP具有4个峰,分别属于类芳香蛋白质、类色氨酸蛋白质、类腐殖酸物质和类富里酸物质.气质联用(GC-MS)分析表明SMP主要成分为酯类、短链烷烃、烯烃和醇类,所占质量分数分别为39.0%、14.9%、11.7%和7.6%.其中邻苯二甲酸二酯是出水SMP中主要组成物质,所占质量分数为32.0%.

Using flocculent activated sludge as seed sludge to cultivate aerobic granular sludge in a SBR,the main objective of this study was focused on the accumulation,relative molecular mass distribution,and composition of soluble microbial products（SMP） in an aerobic granular sludge（AGS） system. SMP were predominant（71-85 mg·L-1） in the effluent of the AGS system. The formation of SMP was related to substrate utilization,biomass decay,and EPS hydrolysis. A relative molecular mass distribution analysis indicated that the majority of SMP,accounting for about 54. 8%-71. 7%,had Mr 3 × 10^3; whereas,the Mr 100 × 10^3 formed a small fraction,constituting only 9. 3%-14. 5%. Three-dimensional excitation emission matrix fluorescence spectra（3 D-EEM）identified four peaks in SMP,belonging to aromatic protein-like,tryptophan protein-like,humic acid-like,and fulvic acid-like substances. Gas chromatography-mass spectrometry（GC-MS） analysis revealed that esters（39. 0%）,short chain alkanes（14. 9%）,alkenes（11. 7%）,and alcohols（7. 6%） were the main compounds in SMP. Most notably,bis（2-ethylhexyl） phthalate,as one kind of ester,accounted for 32% of the identified SMP.