OBTAINING COMPLETE MIXING USING HYDRODYNAMIC ANALYSIS ON BATCH REACTOR

Abstract

This research aims to find the best possible mixing conditions in a multi-phase reactor consist of
wastewater, activated sludge and aeration. This has been done by analyzing flow profiles in the system using
experimental and computational work. Hydrodynamic characteristics, such as influent flow rate, aerator
configuration, baffle installment, play important role for wastewater treatment process. Determination of influent
flow rate and the reactor configuration have done by analyzing flow profile in laboratory scale single-phase
reactor with the dimension of 16 L. Velocity profile was developed from tracer study. There were 2 influent flow
rate variations of 0,0095 L/s and 0,02 L/s, in 3 variations of reactor configuration. The first variation was without
modification (control), the second was baffled reactor and the third was porous reactor. From the experimental
work, it was obtained that the influent flow rate of 0,0095 L/s gave longer Residence Time Detention (RTD) and
longer time to reach the outlet than flow rate of 0,02 L/s. The baffled configuration gave longer RTD and longer
time to reach the outlet as well than other configuration. This two results was reasonable since the first influent
flow rate and the baffled reactor have higher effective volume than other variations. In multi-phase system,
experimental work was done in batch system to observe the contact between air-bubble and sludge in reactor,
which then calibrated using CFD (Computational Fluid Dynamic) model. The result showed that the model of
mixture in k- equation was considerable to use in future simulation work. The using of diffuser could increase
mixing condition inside the reactor due to its higher effective volume.