In this study, the impact of turbulent diffusion on mixing of biochemical reaction models is explored by implementing and validating different models. An original codebase called CHAD (Coupled Hydrodynamics and Anaerobic Digestion) is extended to incorporate turbulent diffusion and validate it against results from OpenFOAM with 2D Rayleigh-Taylor Instability and lid-driven cavity simulations. The models are then tested for the applications with Anaerobic Digestion - a widely used wastewater treatment method. The findings demonstrate that the implemented models accurately capture turbulent diffusion when provided with an accurate flow field. Specifically, a minor effect of chemical turbulent diffusion on biochemical reactions within the anaerobic digestion tank is observed, while thermal turbulent diffusion significantly influences mixing. By successfully implementing turbulent diffusion models in CHAD, its capabilities for more accurate anaerobic digestion simulations are enhanced, aiding in optimizing the design and operation of anaerobic digestion reactors in real-world wastewater treatment applications.

翻译：本研究通过实施并验证不同模型，探讨了湍流扩散对生化反应模型混合过程的影响。我们扩展了原始代码库CHAD（耦合水动力学与厌氧消化系统），在其中纳入湍流扩散模型，并利用OpenFOAM的二维瑞利-泰勒不稳定性与方腔驱动流模拟结果进行验证。随后，该模型被应用于厌氧消化（一种广泛使用的污水处理方法）场景进行测试。结果表明，当提供精确流场时，所实施的模型能够准确捕捉湍流扩散效应。具体而言，在厌氧消化池内观察到化学湍流扩散对生化反应影响甚微，而热湍流扩散则显著影响混合过程。通过成功在CHAD中实现湍流扩散模型，其模拟厌氧消化的精度得到提升，从而有助于优化实际污水处理中厌氧消化反应器的设计与运行。