• Media type: E-Article
  • Title: EDTA: a synthetic draw solute for forward osmosis
  • Contributor: Lutchmiah, Kerusha; Post, Jan W.; Rietveld, Luuk C.; Cornelissen, Emile R.
  • Published: IWA Publishing, 2014
  • Published in: Water Science and Technology, 70 (2014) 10, Seite 1677-1682
  • Language: English
  • DOI: 10.2166/wst.2014.424
  • ISSN: 0273-1223; 1996-9732
  • Origination:
  • Footnote:
  • Description: The draw solution is the driving force of the forward osmosis (FO) process; however, the solute loss of the draw solute to the feed side is a general, financial limitation for most applications. The anthropogenic amino acid ethylenediaminetetraacetic acid (EDTA) was investigated as a draw solution for FO. At concentrations of approximately 1.0 osmol/kg, EDTA demonstrated comparable water fluxes (Jv = 5.29 L/m2 h) to the commonly used salt, NaCl (Jv = 4.86 L/m2 h), and both produced better water fluxes than glucose (Jv = 3.46 L/m2 h). EDTA showed the lowest solute loss with Js (reverse solute loss or solute leakage) = 0.54 g/m2 h. The molecular weight, degree of ionisation and charge of EDTA played a major role in this efficiency and EDTA was therefore well rejected by the membrane, showing a low Js/Jv ratio of 0.10 g/L. Owing to the low solute loss of EDTA and its resistance to biodegradation, this compound has the potential to be used as a draw solute for FO during long periods without requiring much replenishment.