有机质组分对发酵工业污泥脱水性能的影响

Effects of Organic Matter Components on De-watering Performance of Surplus Activated Fermented Sludge in Biological Fermentation Industry

该研究选取了味精、柠檬酸、酱油、食醋、赖氨酸和酵母6种典型生物发酵制品工业的废水污泥,开展了污泥有机质(VS/TS)、流变特性、胞外聚合物(EPS)与污泥脱水性能的分析及相关性研究。结果表明,发酵工业的剩余污泥VS/TS为62.22%~82.53%,脱水性能差异较大,酵母和柠檬酸污泥的脱水性能最差,毛细吸水时间(CST)分别高达(259.44±9.87)s和(251.71±8.85)s,污泥比阻(SRF)分别为(3.85±0.21)×10^(14)m/kg和(2.61±0.17)×10^(14)m/kg,其次为食醋和味精污泥;不同污泥的初始表观黏度(剪切速率10 s^(-1))相比极限表观黏度(剪切速率300 s^(-1))的差异更大,但都与CST和SRF成极显著正相关,说明发酵工业的污泥为黏度值越大污泥脱水性能越差。然而CST、SRF、污泥黏度等都与污泥的VS/TS成反比,与市政污泥结果相反。污泥EPS中有机质组分分析结果表明,除赖氨酸污泥外的其他污泥有机组分总量均为蛋白质>多糖>腐殖酸,酵母和柠檬酸污泥的蛋白质总量分别达(624.96±24.08)mg/(gTS)和(361.30±3.11)mg/(gTS),赖氨酸污泥的多糖总量高达(361.59±11.60)mg/(gTS);蛋白质在污泥各EPS层的含量分布均为TB-EPS>Slime-EPS>LB-EPS,且近50%的蛋白质和多糖分布在TB-EPS层中;从荧光光谱的分析来看,色氨酸类蛋白质在各EPS中占比最大,是主要蛋白类物质。脱水性能的相关性分析表明,污泥中腐殖酸及蛋白质组分与黏度、CST和SRF均成显著正相关,蛋白质对污泥黏度和脱水性能的影响比腐殖酸更大,Slime-EPS和LB-EPS层的蛋白质含量对污泥脱水性能的影响更显著。

To investigate sludge organic matter(VS/TS),the related rheological properties,extracellular polymeric substances(EPS),and sludge de-watering performances with respect to analysis and others,samples of six types of surplus activated sludge were taken from the typical bio-fermentation products enterprises in China,including the manufacturers of monosodium glutamate,citric acid,soy sauce,vinegar,lysine and yeast.Findings of the study revealed that VS/TS content of the surplus activated sludge in biological fermentation industry ranged from 62.22%to 82.53%,and the sludge de-watering performances varied quite a little;the sludge de-watering performances of yeast and citric acid production was the worst of all,with the values of capillary suction time(CST)being respectively(259.44±9.87)s and(251.71±8.85)s,and specific resistance of filtration(SRF)being(3.85±0.21)×10^(14)m/kg and(2.61±0.17)×10^(14)m/kg,respectively,the next being the sludge from manufacturers of vinegar and monosodium glutamate;the initial viscosity(shear rate 10 s^(-1))of different sludge changed far greater than infinite viscosity(shear rate 300 s^(-1)),but all the sludges had significant positive correlation with CST and SRF,which indicated the characteristics of sludge from biological fermentation industry featured:the greater the viscosity value,the worse the sludge de-watering performance;and CST,SRF,sludge viscosity and others were however inversely proportional to the organic matter content(VS/TS),that was contrary to the characteristics of the surplus sludge from municipal sewage treatment plants.The analysis of sludge organic matter components in EPS showed that the amount of organic components in all kinds of the sludge(except for lysine sludge)ranked in descending order:protein>polysaccharide>humic acid;the total protein contents of yeast and citric acid sludge were(624.96±24.08)mg/(g TS)and(361.30±3.11)mg/(g TS),respectively,and the total polysaccharide content of lysine sludge was as high as(361.59±11.60)mg/(g TS);the distribution of protein content in EPS layers of the above-mentioned sludge was TB-EPS>Slime-EPS>LB-EPS,and nearly half of the protein and poly-saccharide contents were found in TB-EPS layer.In view of the analysis of three-dimensional excitation-emission matrix(3D-EEM)fluorescence spectroscopy,tryptophan protein,being the main protein substance,accounted for the largest proportion of each EPS.In addition,correlation analysis with de-watering performance showed that humic acid and protein components in sludge were significantly positively correlated with viscosity,CST and SRF;protein had greater impacts on sludge viscosity and de-watering performance than humic acid;and the protein content of Slime-EPS and LB-EPS much more affected sludge de-watering performance.