University of Wollongong
Browse

Effects of caustic cleaning on pore size of nanofiltration membranes and their rejection of trace organic chemicals

Download (465.93 kB)
journal contribution
posted on 2024-11-16, 08:52 authored by Alexander Simon, James A McDonald, Stuart J Khan, William PriceWilliam Price, Long Nghiem
The aim of this study was to assess the impact of caustic cleaning on the rejection of three different trace organic chemical (TrOC) groups (i.e. neutral hydrophilic, neutral hydrophobic and negatively charged) by two nanofiltration (NF) membranes ‒ namely NF270 and NF90. Chemical cleaning was simulated by exposing virgin membrane samples to commercial caustic cleaning formulations as well as sodium hydroxide solutions containing analytical grade additives such as sodium dodecyl sulfate or ethylenediaminetetraacetic acid. The membrane average pore size before and after exposure to a commercially available caustic cleaning formulation was determined based on the pore transport model. The results show that caustic chemical cleaning could cause an increase in the membrane pore size, leading to an increase in permeability and decrease in rejection of conductivity. The impact of caustic cleaning on the pore size and solute rejection was a function of the membrane active skin layer and the chemistry of the cleaning formulation. Caustic cleaning led to a small increase in pore size of the NF270 membrane and resulted in a notable increase in the permeability and salt passage. By contrast, the impact on the NF90 membrane was negligible. The influence of caustic cleaning on TrOC rejection was dependent on physical characteristics of each TrOC including their molecular size, charge, and hydrophobicity. The rejection of neutral and hydrophobic TrOC by the NF270 membrane decreased significantly after exposure to caustic cleaning formulation. However, because the rejection of negatively charged TrOC is governed mostly by electrostatic interaction, their rejection was not significantly affected by caustic cleaning.

Funding

Optimising nanofiltration and reverse osmosis filtration processes for water recycling: effects of fouling and chemical cleaning on trace contaminant removal

Australian Research Council

Find out more...

History

Citation

Simon, A., McDonald, J. A., Khan, S. J., Price, W. E. & Nghiem, L. D. (2013). Effects of caustic cleaning on pore size of nanofiltration membranes and their rejection of trace organic chemicals. Journal of Membrane Science, 447 153-162.

Journal title

Journal of Membrane Science

Volume

447

Pagination

153-162

Language

English

RIS ID

80991

Usage metrics

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC