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Effects of membrane fouling on the nanofiltration of trace organic contaminants

Journal Article


Abstract


  • Organic fouling and its effects on trace organic retention by three nanofiltration (NF) membranes were investigated

    in this study. Accelerated fouling conditions were achieved with foulant cocktails containing humic acids

    in a background electrolyte solution. The effects of membrane fouling on the separation process were delineated

    by comparing the retention values of clean and fouled membranes and relate them to the membrane pore size as

    well as physicochemical characteristics of the trace organics. Fouling was more severe for the more open pore size

    TFC-SR2 and NF-270 membranes as compared to the tighter NF-90 membrane. Results reported here indicate

    that retention of trace organics by NF membranes was governed by steric hindrance, electrostatic, and hydrophobic

    interactions. However, steric hindrance (or size exclusion) appears to be the most prevalent mechanism

    controlling not only trace organic retention but also the membrane fouling process as well as the effects of fouling

    on retention. Pore blocking was a major reason for the more severe fouling by the loose nanofiltration TFC-SR2

    membrane as compared to the NF-270 and NF-90 membranes which had smaller membrane pore size. Considerable

    increase in retention of trace organics by the TFC-SR2 membrane under fouled conditions was probably attributed to

    pore blocking, which was a dominating foulingmechanismfor this loose NFmembrane.While retention increase due

    to pore blocking was probably limited to only the TFC-SR2 membrane, retention of hydrophobic trace organics

    was enhanced under fouled conditions by all three membranes. This enhancement in retention of the hydrophobic

    trace organics could be explained by the formation of a fouling layer which reduced hydrophobic interaction

    between the hydrophobic trace organics and the membrane surface, hence reducing diffusional transport across

    the membrane.

Publication Date


  • 2009

Citation


  • Nghiem, L. D. & Hawkes, S. (2009). Effects of membrane fouling on the nanofiltration of trace organic contaminants. Desalination, 236 (1-3), 273-281.

Scopus Eid


  • 2-s2.0-57949087070

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 273

End Page


  • 281

Volume


  • 236

Issue


  • 1-3

Abstract


  • Organic fouling and its effects on trace organic retention by three nanofiltration (NF) membranes were investigated

    in this study. Accelerated fouling conditions were achieved with foulant cocktails containing humic acids

    in a background electrolyte solution. The effects of membrane fouling on the separation process were delineated

    by comparing the retention values of clean and fouled membranes and relate them to the membrane pore size as

    well as physicochemical characteristics of the trace organics. Fouling was more severe for the more open pore size

    TFC-SR2 and NF-270 membranes as compared to the tighter NF-90 membrane. Results reported here indicate

    that retention of trace organics by NF membranes was governed by steric hindrance, electrostatic, and hydrophobic

    interactions. However, steric hindrance (or size exclusion) appears to be the most prevalent mechanism

    controlling not only trace organic retention but also the membrane fouling process as well as the effects of fouling

    on retention. Pore blocking was a major reason for the more severe fouling by the loose nanofiltration TFC-SR2

    membrane as compared to the NF-270 and NF-90 membranes which had smaller membrane pore size. Considerable

    increase in retention of trace organics by the TFC-SR2 membrane under fouled conditions was probably attributed to

    pore blocking, which was a dominating foulingmechanismfor this loose NFmembrane.While retention increase due

    to pore blocking was probably limited to only the TFC-SR2 membrane, retention of hydrophobic trace organics

    was enhanced under fouled conditions by all three membranes. This enhancement in retention of the hydrophobic

    trace organics could be explained by the formation of a fouling layer which reduced hydrophobic interaction

    between the hydrophobic trace organics and the membrane surface, hence reducing diffusional transport across

    the membrane.

Publication Date


  • 2009

Citation


  • Nghiem, L. D. & Hawkes, S. (2009). Effects of membrane fouling on the nanofiltration of trace organic contaminants. Desalination, 236 (1-3), 273-281.

Scopus Eid


  • 2-s2.0-57949087070

Has Global Citation Frequency


Number Of Pages


  • 8

Start Page


  • 273

End Page


  • 281

Volume


  • 236

Issue


  • 1-3