研究报告

  • 董登志,张静思,吴志根,李卓.对影响热水解污泥临界剪切应力主要因素的实验研究[J].环境科学学报,2018,38(2):553-559

  • 对影响热水解污泥临界剪切应力主要因素的实验研究
  • The influencing factors on the critical shear stress of thermal hydrolyzed sludge
  • 基金项目:国家自然科学基金(No.51676141,21307092);中央高校基本科研业务费专项资金
  • 作者
  • 单位
  • 董登志
  • 同济大学污染控制与资源化研究国家重点实验室, 上海 200092
  • 张静思
  • 同济大学污染控制与资源化研究国家重点实验室, 上海 200092
  • 吴志根
  • 同济大学污染控制与资源化研究国家重点实验室, 上海 200092
  • 李卓
  • 同济大学污染控制与资源化研究国家重点实验室, 上海 200092
  • 摘要:热水解广泛应用于污泥厌氧消化的预处理之中,研究热水解污泥临界剪切应力的主要影响因素,准确预测污泥流变特性,对后续厌氧反应器的有效运行是十分必要的.本文研究了预剪切强度、温度(15~85℃)、浓度(8.6%~15.6%)、剪切速率范围(0.01~1000 s-1)对热水解污泥临界剪切应力的影响.实验采用含固率(Total solid,简称TS)8.6% < TS < 15.6%的热水解污泥,在0.01~1000 s-1的剪切速率范围内对热水解污泥进行流变特性的测试.结果发现:流动曲线中是否出现临界剪切应力与污泥浓度和剪切速率范围有关,与预剪切强度及温度无关.对于160℃-30 min的热水解污泥而言,当TS<10%时,流动曲线符合Herschel-Bulkley模型;当TS=10%时,在0.1~10 s-1内开始出现临界剪切应力将流动曲线分为两部分;TS>10%时,流动曲线符合改进的Herschel-Bulkley模型.
  • Abstract:Thermal hydrolysis is a widely used pretreatment method in anaerobic digestion system. The influencing factors on the critical shear stress of thermal hydrolyzed sludge and accurate prediction of flow behavior are essential for the subsequent anaerobic digestion. In this work, rheological experiments were conducted to study the effects of pre-shear intensity, temperature(15~85℃), total solid (8.6%~15.6%), and the range of shear rate (0.01~1000 s-1) on the critical shear stress within the flow curves. Thermal hydrolyzed sludges with TS content of 8.6%~15.6% were sheared from 0.01 s-1 to 1000 s-1. The results indicate that the critical shear stress depends on TS content and the range of applied shear rate, rather than the intensity of pre-shear and tested temperature. For the sludges with TS less than 10%, the flow curve can be fitted well by the Herschel-Bulkley model; for the sludges with TS equal to 10%, a critical shear stress appeared on the flow curve within the shear rate of 0.1~10 s-1 and divided the flow curve into two sections; for the sludges with TS more than 10%, the flow curves can be fitted well by the revised Herschel-Bulkley model.

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