Nanofiltration of magnesium chloride, sodium carbonate, and calcium sulphate in salt solutions

N. Hilal, H. Al-Zoubi, N. A. Darwish, A. W. Mohammad

Research output: Contribution to journalArticle

Abstract

Nanofiltration (NF) membranes have been employed in pretreatment unit operations in both thermal and membrane seawater desalination processes. This has resulted in reduction of chemicals used in pretreatment processes as well as lowering the energy consumption and water production cost and, therefore, has led to a more environmentally friendly processes. In order to predict NF membrane performance, a systematic study on the filtration performance of selected commercial NF membranes against brackish water and seawater is required. In this study, three commercial nanofiltration membranes (NF90, NF270, N30F) have been used to treat highly concentrated different salts solutions (MgCl2, Na2CO3, and CaSO4) at salinity level similar to that of brackish water and seawater. The main parameters studied in this paper are salt concentration and feed pressure. The experimental data were correlated and analysed using the SpieglerKedem model. In particular, the reflection coefficient (σ) of all studied membranes and the solute permeability (Ps ) have been determined for all membranes and at different salinity levels of studied salts. All the studied membranes fitted the model well for all investigated salts except the experimental data of MgCl2 using N30F membrane, which did not fit well at low rejection. The results showed that NF90 produced a high rejection around 97% for all salts with medium permeate flux while NF270 gave a high flux with medium rejection and N30F gave low rejection and flux.

Original languageEnglish (US)
Pages (from-to)3299-3321
Number of pages23
JournalSeparation Science and Technology
Volume40
Issue number16
DOIs
StatePublished - Dec 1 2005

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Keywords

  • Membrane
  • Nanofiltration
  • Permeate flux
  • Pre-treatment
  • Salt rejections
  • Seawater
  • Spiegler-Kedem model

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Process Chemistry and Technology
  • Filtration and Separation

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