Laboratory of Reactions and Process Engineering, University of Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France; CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei 230026, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Bioresour Technol. 2016 Oct;218:301-6. doi: 10.1016/j.biortech.2016.06.101. Epub 2016 Jun 27.
An impact method was applied to investigate the rheological characteristics of digested sludge and reveal its transient dynamics. A high-speed camera allowed visualizing the dynamic impact process and observing interaction between impacting sphere and targeted sludge. A damping oscillation was observed after the impact. The crater diameter followed an exponential function, while the crater depth varied as a logarithmic function of both sphere diameter and free fall height. Furthermore, the viscosity and elasticity of digested sludge were evaluated by establishing a simplified impact drag force model. The impact elastic modulus was consistent with the Young's modulus measured by a penetrometer. The impact viscosity was reasonable as the estimated impact shear stress was greater than the yield stress of digested sludge resulting in the formation of crater. The impact method offers an alternative way to reveal the viscoelasticity of digested sludge through a dynamic process.
采用冲击法研究了消化污泥的流变特性，揭示了其瞬态动力学特性。高速摄像机允许可视化冲击过程，并观察冲击球和目标污泥之间的相互作用。冲击后观察到阻尼振荡。弹坑直径遵循指数函数，而弹坑深度随球直径和自由落体高度的对数而变化。此外，通过建立简化的冲击阻力模型来评估消化污泥的粘度和弹性。冲击弹性模量与通过贯入仪测量的杨氏模量一致。冲击粘度是合理的，因为估计的冲击剪切应力大于消化污泥的屈服应力，导致弹坑的形成。冲击法通过动态过程提供了一种揭示消化污泥粘弹性的替代方法。
