Experimental determination of liquid entry pressure (LEP) in vacuum membrane distillation for oily wastewaters

Gábor Rácz, Steffen Kerker, Oliver Schmitz, Benjamin Schnabel, Zoltán Kovács, Gyula Vatai, Mehrdad Ebrahimi, Peter Czermak

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15 Citations (Scopus)


In this study we investigate a laboratory scale vacuum membrane distillation system to produce pure water from model oil in water emulsion. Experimental determination of liquid entry pressure (LEP) of a commercial DuraporeTM GVPH flat sheet membrane using model emulsions in various oil concentrations has been carried out. Two different methods of liquid entry pressure determination - a frequently used, so-called static and a novel dynamic method - have been investigated. In case of static method, LEP value was found to be 2.3 bar. No significant effect of oil content on LEP was detected up to 3200 ppm. In contrast, LEP values determined with dynamic method showed strong dependence on the oil concentration of the feed and decreased from 2.0 bar to a spontaneous wetting at 0.2 bar in the range 0-250 ppm, respectively. Vacuum membrane distillation tests were also performed. The separation performance is evaluated in terms of flux behavior, total organic carbon removal and droplet size distribution of the feed and final retentate. No significant effect of oil content on the flux was found (5.05 ± 0.31 kgm-2h-1) up to 250 ppm, where a spontaneous wetting occurred. High separation performance was achieved along with the increasing oil concentration between 93.4-97.0%.

Original languageEnglish
Pages (from-to)237-249
Number of pages13
JournalMembrane Water Treatment
Issue number3
Publication statusPublished - Jan 1 2015



  • Liquid entry pressure
  • Oil in water emulsion
  • Produced water purification
  • Vacuum membrane distillation
  • Wetted membranes
  • Wetting phenomenon

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Water Science and Technology

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