Development and Validation of a PIV System for Obtaining Data from a UASB Reactor

Anaerobic digestion processes can generate energy in the form of biogas while treating organic wastewater. The efficiency of the treatment, and thus the generation of biogas, is closely linked to the type and design of the reactor, and the technology used. Granular anaerobic digestion technology offers advantages such as a higher loading rate and reduction of the space needed. However, the hydrodynamics inside this type of reactor can be complex due to the presence of solids (granules) and gas (biogas) phases along with the liquid phase (wastewater). This is one of the reasons why the study and optimization of reactors using bench-scale reactors can lead to inaccurate results. A validated computational model would lead to the possibility of performing optimization studies using simulation; however, the validation of these computational models cannot be performed using analytical solutions due to their complexity. In this context, a particle image velocimetry (PIV) experimental setup was validated as part of this work, using computational fluid dynamics (CFD) simulations and data from literature. The experimental results obtained were compared with CFD results from six different models, each using a different turbulence model. The current setup was considered validated, allowing it to be used in the future for obtaining experimental data for the validation of a CFD model of an up-flow anaerobic sludge blanket reactor (UASB).