Emulsion

An emulsion is a dispersion of one immiscible liquid in another (e.g., oil in water or water in oil) stabilised by interfacial tension reducers and surfactants. Droplet size distribution, continuous phase viscosity and interfacial chemistry determine separation difficulty: fine, stable droplets resist coalescence and readily foul conventional filter media. Industrial strategies for handling emulsions combine conditioning and tailored media. Coagulants or demulsifiers neutralise charges and displace surfactants; temperature adjustment lowers viscosity; gentle mixing promotes droplet encounters without re‑dispersing. On the hardware side, oleophilic/oleophobic surface treatments on meshes encourage selective capture or coalescence; multilayer coalescer media grow droplets that then separate by gravity; and crossflow modules maintain shear to limit cake growth. Specifications should reference droplet size at the most penetrating range, interfacial tension, expected loading and allowable residual oil in the filtrate, with CIP procedures defined to remove tenacious films. Correctly designed, emulsion treatment delivers stable flux and compliance with discharge or product‑purity limits.