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Effect of viscosity on the mixing efficiency in a self-agitation anaerobic baffled reactor

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Abstract

One special self-agitation reactor, which does not require a mechanical mixer or other equipment for mixing, has been introduced. Self-agitation is affected by variation in viscosity property. To obtain and research the effect of viscosity on mixing behavior in the self-agitation reactor, Fluent® was used to create numerical simulations and to visualize the fluid flow status. The results show that when the viscosity of the liquid is 1 mPa s, the entire self-agitation results in an almost completely mixed reactor. The substrate becomes difficult to agitate, and the diffusion of the substrate and the tracer become quite after every self-agitation, as the viscosity increases. Once the viscosity is higher than 25 mPa s, the substrate and tracer could not be mixed in the entire reactor, and the reactor is recognized as the combination of several completely mixed reactors between which little exchange of liquid occurs.

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Acknowledgments

This project was supported by the Major Science and Technology Program for Water Pollution Control and Treatment (project 2011ZX07301-003-05). The authors gratefully acknowledge the trust and support of all the members of the research team.

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Correspondence to Yu-You Li.

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Qi, W., Guo, Y., Xue, M. et al. Effect of viscosity on the mixing efficiency in a self-agitation anaerobic baffled reactor. Bioprocess Biosyst Eng 38, 905–910 (2015). https://doi.org/10.1007/s00449-014-1334-y

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Keywords

  • Anaerobic digestion
  • Viscosity
  • Self-agitation
  • CFD
  • Flow state