The role of NOM fouling for the retention of estradiol and ibuprofen during ultrafiltration

Doris Jermann, Wouter Pronk, Markus Boller, Andrea I. Schaefer

Research output: Contribution to journalArticlepeer-review

Abstract

The impact of membrane fouling by natural organic matter (NOM) on the behavior of micropollutants during ultrafiltration (UF) was investigated. Batch experiments with radioactively labeled estradiol and ibuprofen in the presence of NOM model compounds (alginate, Nordic aquatic and Aldrich humic acid) were performed using a hydrophilic and a hydrophobic membrane. The results indicate that the impact of the NOM fractions studied on micropollutant retention correlated with the fouling mechanism of the individual NOM fractions. NOM substances of high molecular weight such as alginate and Aldrich HA that foul the membrane by pore blocking and cake/gel formation had a greater impact than the Nordic aquatic humic acid of lower molecular weight. The effect of cake formation was attributed partly to micropollutant-NOM partitioning and subsequent NOM retention and partly to the effect of the fouling layer itself acting as a kind of second membrane. Fouling by NOM cake/gel formation led to a significantly increased retention of estradiol, whereas the impact Of fouling on ibuprofen retention was negligible due to significantly lower log K-oc values of ibuprofen compared to estradiol. Moreover, NOM adsorption on the membrane can lower the adsorption of hydrophobic micropollutants. Membrane adsorption of estradiol was in the order of mg/m(2) and was largely reversible with caustic solutions. The results of this study may prove useful for predicting the mass flow of micropollutants in UF applications. (c) 2009 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)75-84
Number of pages10
JournalJournal of Membrane Science
Volume329
Issue number1-2
DOIs
Publication statusPublished - 5 Mar 2009

Keywords

  • Ultrafiltration
  • Natural organic matter
  • Fouling mechanisms
  • Estradiol
  • Ibuprofen
  • ENHANCED CONCENTRATION POLARIZATION
  • PHARMACEUTICALLY ACTIVE COMPOUNDS
  • ENDOCRINE DISRUPTING COMPOUNDS
  • DISSOLVED ORGANIC-MATTER
  • NANOFILTRATION MEMBRANES
  • WASTE-WATER
  • HUMIC-ACID
  • AQUATIC ENVIRONMENT
  • REVERSE-OSMOSIS
  • BISPHENOL-A

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