Numerical study of bacteria removal from microalgae solution using an asymmetric contraction-expansion microfluidic...

Area of Science:

• Biotechnology and Bioengineering
• Microfluidics
• Separation Science

Background:

• Microalgae are vital for biopharmaceutical, nutraceutical, and bio-energy applications.
• Bacterial contamination of microalgae reduces product quality and process efficiency.
• Conventional decontamination methods are costly, time-consuming, and can damage microalgae.

Purpose of the Study:

• To numerically investigate asymmetric contraction-expansion microchannels (Asym-CEMCs) for microalgae decontamination.
• To evaluate the impact of geometrical parameters and flow rate on bacterial removal efficiency.
• To optimize Asym-CEMC design for effective separation of bacteria from microalgae.

Main Methods:

• A 3D numerical model was employed to simulate particle separation within Asym-CEMCs.
• Investigated parameters included microchannel aspect ratio, expansion-to-contraction ratios, and total flow rate.
• Focused on the removal of B. subtilis (1 μm) from C. vulgaris (5.7 μm).

Main Results:

• Microchannel aspect ratio significantly influenced separation performance; lower ratios improved resolution.
• Increased total flow rate and expansion-to-contraction width ratio enhanced microalgae decontamination.
• An optimized Asym-CEMC design achieved complete bacterial removal with a normalized separation resolution of 0.6.

Conclusions:

• Asym-CEMCs offer a promising passive microfluidic solution for microalgae decontamination.
• Tailored Asym-CEMC dimensions are crucial for achieving high separation efficiency.
• This technology can overcome limitations of conventional decontamination techniques.