Crossflow ultrafiltration of surfactant solutions

Ultrafiltration has been used as an effective process to remove heavy metals and organic pollutants from contaminated-groundwater and wastewater or as a part of surfactant-enhanced aquifer remediation (SEAR) process to concentrate and reuse the surfactant. The objective of this study was to investigate the effects of surfactant types, hydrophile-lipophile balance (HLB), salt amount, humic acid, and clay on the ultrafiltration: permeate concentration and flux. The regenerated cellulose membrane of 10K MWCO was used throughout the experiment. The flux was dependent on the viscosity of surfactant solution and water solubility of surfactant. Higher viscosity and lower water solubility caused the decrease of flux. The permeate concentration of surfactant was a function of the critical micelle concentration of surfactant. In the case of anionic surfactants, the permeate concentration decreased as salts concentration increased. The lower of HLB value caused the flux decline and higher concentration of permeate. Humic acid and clay decreased the flux. The permeate concentration of surfactant was not significantly influenced by the existence of humic acid and clay.