Impact of Particle Shape and Surface Group on Membrane Fouling

Area of Science:

• Membrane science and filtration technology.
• Colloid and surface chemistry.

Background:

• Membrane fouling is a major limitation in membrane filtration.
• Existing research often overlooks the influence of particle shape on fouling dynamics.

Purpose of the Study:

• To investigate the effect of polystyrene particle sphericity and surface charge on external membrane fouling.
• To compare the fouling behavior of spherical versus non-spherical particles (peanut, pear).

Main Methods:

• Experimental membrane filtration using polystyrene particles of varying shapes and surface charges.
• Analysis of critical flux and flux decline under different operating conditions.
• Modeling of particle-membrane interactions using Derjaguin-Landau-Verwey-Overbeek (DLVO) and extended DLVO (XDLVO) models.

Main Results:

• Non-spherical particles exhibited higher critical fluxes (24% for peanut, 13% for pear) compared to spherical particles due to looser cake packing.
• Particle shape effects on critical flux were more pronounced than surface charge effects, especially at higher crossflow velocities.
• Non-spherical particles led to lower flux declines in dead-end filtration.
• Shear-induced diffusion, DLVO, and XDLVO models effectively predicted particle behavior and fouling trends.

Conclusions:

• Particle shape is a crucial factor influencing membrane fouling, often more so than surface charge.
• Non-spherical particles can improve membrane performance by increasing critical flux and reducing fouling.
• The extended DLVO model accurately describes the interaction energies governing fouling behavior based on particle shape.