王彦祥,何琴,李蕾,彭绪亚.餐厨垃圾中温干式厌氧消化污泥的流变特性研究[J].环境科学学报,2014,34(12):3171-3178
餐厨垃圾中温干式厌氧消化污泥的流变特性研究
- Rheological characteristic analysis of dry anaerobic digestion sludge of food waste under mesophilic conditions
- 基金项目：国家科技支撑计划项目(No.2010BAC67B01);重庆市科技计划重点项目
- 王彦祥
- 重庆大学 三峡库区生态环境教育部重点试验室, 重庆 400045
- 何琴
- 重庆大学 三峡库区生态环境教育部重点试验室, 重庆 400045
- 李蕾
- 重庆大学 三峡库区生态环境教育部重点试验室, 重庆 400045
- 彭绪亚
- 重庆大学 三峡库区生态环境教育部重点试验室, 重庆 400045
- 摘要：以半连续式和序批式餐厨垃圾厌氧消化产生的污泥为研究对象,考察温度(T)、含固率(TS)和剪切速率(γ)对消化污泥流变性的影响.使用旋转粘度计测定污泥动力粘度,测定时温度范围20~70 ℃,消化污泥TS分别为21.41%~29.54%(半连续式)、12.09%~22.48%(序批式).试验结果表明:污泥流动性随温度升高而增强,随温度降低而减弱,且温度变化会对污泥流变性造成不可逆的影响;同一剪切速率下,污泥的动力粘度随TS含量增高而变大;粘度曲线说明厌氧消化污泥为非牛顿流体,具有剪切变稀的特点;通过剪切应力的上升曲线和下降曲线可判断厌氧消化污泥为时间相关性流体,动力粘度-时间曲线进一步说明污泥为触变性流体;TS>12%时,有必要设置搅拌系统,剪切速率控制在10.4~20.9 s-1较为合适;污泥的TS含量越高,温度、TS和剪切对流变性的影响越明显.试验可为厌氧消化反应器的搅拌系统和热交换系统设计提供一定的基础数据.
- Abstract：The effect of temperature (T), solid content (TS), and shear rate (γ) on rheological characteristics was investigated by using anaerobic digestion sludge of food waste from semi-continuous and sequencing batch reactors. The dynamic viscosity was measured by a rotational viscometer. The sludge temperature was controlled in the range of 20 ℃ to 70 ℃ during all measurements and the TS contents were 21.41%~29.54% and 12.09%~22.48% for semi-continuous and sequencing batch reactor respectively. The results showed that the fluidity of the sludge was enhanced under higher temperature conditions. Temperature variation could cause irreversible effects on sludge rheology. If measured at the same shear rate the dynamic viscosity of the sludge increased with increasing TS content. The viscosity curves revealed that the anaerobic digestion sludge was non-Newtonian fluid with shear-thinning characteristics. The increasing and decreasing curves of shear stress-shear rate demonstrated that the anaerobic sludge was time-related fluid and the viscosity-time curves further indicated that the anaerobic digestion sludge was thixotropic fluid. A stirring system is essential when TS>12% and the shear rate should be controlled between 10.4 s-1 to 20.9 s-1. The effect of temperature, TS and shear rate on rheology was enhanced with higher TS content. This work provides basic information for designing stirred system and heat exchange system of anaerobic digestion reactors.
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