Nature identification and morphology characterization of cation-exchange membrane fouling during conventional electrodialysis.
The aim of this work was to study the effect of a concentrate solution pH value and of the composition in calcium, carbonate, and protein of a diluate solution to be treated by conventional electrodialysis on the fouling of cation-exchange membranes (CEM). It appeared that after demineralization of solutions containing CaCl(2) and CaCl(2)+Na(2)CO(3) using a concentrate solution maintained at a pH of 12, mineral fouling appeared on both sides of the CEM. The nature of the deposits was identified as calcium hydroxide and/or carbonate on both surfaces. The mineral fouling presented an aggregation-like crystal following a carnation-like pattern of aggregates of small rhombohedral crystals with CaCl(2) added alone, while CaCl(2)+Na(2)CO(3) yielded a smoother spherical crystal. Protein fouling was detected only on the CEM surface in contact with the diluate after demineralization of a solution containing CaCl(2)+Na(2)CO(3) using a concentrate pH value of 2.
Ayala-Bribiesca
Erik
E
Institute of Nutraceuticals and Functional Foods (INAF) and Dairy Research Group (STELA), Department of Food Sciences and Nutrition, Laval University, Sainte-Foy, Québec, Canada G1K 7P4.
Pourcelly
Gérald
G
Bazinet
Laurent
L
D002118:Calcium / Q000737:chemistry; D002122:Calcium Chloride / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D002412:Cations; D002627:Chemistry, Physical / Q000379:methods*; D003956:Dialysis; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared
D002254:Carbonates; D002412:Cations; D008567:Membranes, Artificial; C005686:sodium carbonate; D002122:Calcium Chloride; D002118:Calcium