Fouling Mitigation via Chaotic Advection in a Flat Membrane Module with a Patterned Surface

Area of Science:

• Fluid Dynamics
• Chemical Engineering
• Materials Science

Background:

• Membrane fouling is a significant challenge in membrane processes, reducing efficiency and increasing operational costs.
• Hydrodynamic techniques offer a promising approach to mitigate fouling by manipulating flow patterns.

Purpose of the Study:

• To numerically investigate fouling mitigation using chaotic advection induced by herringbone-shaped grooves in a flat membrane module.
• To analyze the influence of groove geometry on flow characteristics and fouling reduction.

Main Methods:

• Numerical simulation of laminar flow (Reynolds number 50-500) with constant permeate flux.
• Analysis of flow dynamics using Poincaré sections to assess mixing and chaotic behavior.
• Quantification of fouling using dimensionless average concentration (c¯w*) and its growth rate.

Main Results:

• Chaotic flow regimes were achieved above a critical groove depth, significantly influenced by groove depth and Reynolds number.
• Chaotic advection led to a substantial decrease in the growth rate of membrane concentration compared to film theory predictions.
• Optimal groove depths were identified that minimize foulant concentration and growth rate.

Conclusions:

• Chaotic advection generated by herringbone grooves is an effective hydrodynamic strategy for membrane fouling mitigation.
• Optimal groove design can enhance foulant removal from the membrane surface back into the bulk flow.
• This technique presents an attractive solution for improving membrane performance and longevity.