Effect of some operating variables on citrate recovery from model solutions by electrodialysis

Abstract

The effect of pH and temperature (θ) on the overall performance indicators (i.e., solute recovery, ρ, and Faraday, η, efficiencies; specific energy consumption, ϵ, solute, JS, and water, JW, fluxes) of batch electrodialytic recovery of citric acid from model solutions was assessed at different values of feed solute concentration (cSf) and electric current density (j). Regardless of the initial feed concentration used, ρ and JS were found to be independent of θ; η and JW exhibited a positive trend with respect to θ, while ϵ a negative one. At the maximum temperature tested (33°C), as the pH of the feed solution was varied from 3 to 7, ρ increased from 0.90 ± 0.08 to 0.97 ± 0.02, η grew from 0.09 ± 0.02 to 0.50 ± 0.01, JS practically doubled, ϵ reduced about 8 times, but JW increased from 3 to 4 times. So, the optimal conditions for this technique are to be determined by balancing the savings in the investment and maintenance costs against the energy costs. © John Wiley & Sons, Inc. Biotechnol Bioeng 59:344–350, 1998.

Assessment of the main engineering parameters controlling the electrodialytic recovery of sodium propionate from aqueous solutions

“…Membranes were routinely cleaned-in-place by performing a series of re-circulation cycles of 20 min each with neutral (de-ionised water), acidic (HCl at pH 1.0), and alkaline (3 kg m À3 NaOH) solutions, as described before (Moresi & Sappino, 1998;Sappino et al, 1996).…”

“…A laboratory-scale electrodialyser (Aqualyzer P1, Corning EIVS, Le Vesinet, F), previously described (Moresi & Sappino, 1998;Sappino, Mancini, & Moresi, 1996), was used. It was equipped with 2 graphite electrodes and a sheet-flow stack containing N c cation-(CMV) and/or N a anion-(AMV) exchange membranes (Asahi Glass Co. Ltd, Chioda-ku, Tokyo, Japan), separated by spacer gaskets to ensure a flow parallel to the membranes themselves.…”

Modelling the electrodialytic recovery of sodium lactate

“…A laboratory‐scale electrodialyser (Aqualyzer P1; Corning EIVS, Le Vesinet, France), previously described [24,25], was used. It was equipped with two graphite electrodes and a sheet‐flow stack containing N c CMV (cation‐) and/or N a AMV (anion‐) exchange membranes (Asahi Glass Co. Ltd, Chioda‐ku, Tokyo, Japan), separated by spacer gaskets to ensure a flow parallel to the membranes themselves.…”

Electrodialytic desalting of model concentrated NaCl brines as such or enriched with a non-electrolyte osmotic component

“…1 of Ref. [32]. The electric conductivity (Ä) of the solutions flowing out of C and D compartments was on-line measured using two continuous cell flow units (model Tetracon DU/T, WTW, Germany) connected to two WTW conductivity meters (model Inolab Cond Level 1).…”