Hydrodynamic effects on the overall adsorption rate of phenol on activated carbon cloth through the advection-diffusion model application

In this work, a mathematical formulation based on fundamental principles of momentum and mass transport with a kinetic adsorption model at the liquid-solid interface is proposed. This formulation was numerically solved and used for the interpretation of adsorption rate data of phenol onto an activated carbon cloth in a stirred tank adsorber under different agitation rates. The mathematical model solution was compared with the obtained by mathematical models that neglect the local velocity and concentration profiles in the solution; external mass transfer model (EMTM) and the first-order kinetic model (FOM). The results showed that under all studied stirring speeds (30−200 rpm) the proposed model was able to capture the dynamics of the concentration decay curves, while EMTM and FOM models were only able to interpret the data at high stirring speeds, indicating that velocity profiles play an important role during phenol adsorption. Particular “wake zones” were identified behind the mobile adsorbent, which importantly promotes the transport of solute toward the activated carbon cloth. As a result, it was found that convective transport is much more important than diffusive transport in the solution. © 2020 The Korean Society of Industrial and Engineering Chemistry

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