To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability,sludge flocs were stratified into four f...To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability,sludge flocs were stratified into four fractions: (1) slime;(2) loosely bound extracellular polymeric substances (LB-EPS);(3) tightly bound EPS (TB-EPS);and (4) EPS-free pellets.The results showed that ultrasonic pretreatment increased the anaerobic digestion efficiency by 7%–8%.Anaerobic digestion without ultrasonic pretreatment deteriorated the sludge dewaterability,with the capillary suction time (CST) increased from 1.42 to 47.3 (sec·L)/g-TSS.The application of ultrasonic pretreatment firstly deteriorated the sludge dewaterability (normalized CST increased to 44.4 (sec·L)/g-TSS),while subsequent anaerobic digestion offset this effect and ultimately decreased the normalized CST to 23.2 (sec·L)/g-TSS.The dewaterability of unsonicated sludge correlated with protein (p = 0.003) and polysaccharide (p = 0.004) concentrations in the slime fraction,while that of sonicated sludge correlated with protein concentrations in the slime and LB-EPS fractions (p 0.05).Fluorescent excitationemission matrix analysis showed that the fluorescence matters in the LB-EPS fraction significantly correlated with sludge dewaterability during anarobic digestion.展开更多
考察了阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)浓度、添加量、调理时间和温度对活性污泥脱水和沉降性能的影响。结果表明,使用1 m L浓度1%的CTMAB调理污泥效果最佳,重力沉降的滤液体积最大。在最佳用量下,搅拌2 h,搅拌温度60℃时...考察了阳离子表面活性剂十六烷基三甲基溴化铵(CTMAB)浓度、添加量、调理时间和温度对活性污泥脱水和沉降性能的影响。结果表明,使用1 m L浓度1%的CTMAB调理污泥效果最佳,重力沉降的滤液体积最大。在最佳用量下,搅拌2 h,搅拌温度60℃时污泥的脱水性能最好,毛细吸水时间为8. 7 s,泥饼含水率下降了25%。通过SEM观察了原污泥和CTMAB调理后的污泥微观形态。展开更多
基金supported by the National Key Project for Water Pollution Control (No.2008ZX07316-003)the Program of Shanghai Subject Chief Scientist (No.10XD1404200)
文摘To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability,sludge flocs were stratified into four fractions: (1) slime;(2) loosely bound extracellular polymeric substances (LB-EPS);(3) tightly bound EPS (TB-EPS);and (4) EPS-free pellets.The results showed that ultrasonic pretreatment increased the anaerobic digestion efficiency by 7%–8%.Anaerobic digestion without ultrasonic pretreatment deteriorated the sludge dewaterability,with the capillary suction time (CST) increased from 1.42 to 47.3 (sec·L)/g-TSS.The application of ultrasonic pretreatment firstly deteriorated the sludge dewaterability (normalized CST increased to 44.4 (sec·L)/g-TSS),while subsequent anaerobic digestion offset this effect and ultimately decreased the normalized CST to 23.2 (sec·L)/g-TSS.The dewaterability of unsonicated sludge correlated with protein (p = 0.003) and polysaccharide (p = 0.004) concentrations in the slime fraction,while that of sonicated sludge correlated with protein concentrations in the slime and LB-EPS fractions (p 0.05).Fluorescent excitationemission matrix analysis showed that the fluorescence matters in the LB-EPS fraction significantly correlated with sludge dewaterability during anarobic digestion.