Membrane ultrafiltration of a nonionic surfactant

Aqueous solutions 1.65 × 10⁻⁴ to 1.10 × 10⁻² molar in the nonionic surfactant Triton X‐100 are subjected to membrane ultrafiltration over the temperature range of 22 to 50°C in a continuous flow, thin channel cell, with channel Reynolds numbers from 50 to 1175. Data for the ultrafiltrate flux through the optimum polyelectrolyte complex membrane (of the three tested) are correlated by an equation involving the in‐series resistances of the membrane and of the polarized boundary layer of the sufactant rejected by the membrane, with the latter resistance varied over a wide range. The correlations are used to estimate the required membrane area and resultant ultrafiltrate concentration of surfactant to achieve any specified water recovery using cells‐in‐series and cells‐in‐parallel operation. The gelation concentration and surfactant mass transfer coefficient are used to estimate water flux in the gel‐polarization region.