Transport hindrances with electrodialytic recovery of citric acid from solution of strong electrolytes

Electrodialytic (ED) recovery of citric acid (CA) in the presence/absence of strong electrolytes (NaCl, CaCl2 and FeCl3) was separately analyzed under different process conditions. Recovery effectiveness was quantitatively estimated from current efficiency values. Efficiency attained optimum value with both flow rate and potential applied, while a monotonic rise was noted with temperature which got lowered beyond 0.1 mol·L− 1 feed concentration. 40% drop in efficiency was recorded in the presence of strong electrolytes (NaCl, CaCl2 and FeCl3) in feed relative to their presence in concentrate. Severe transport hindrance and efficiency loss were attributed to adsorption and allied physicochemical changes occurred with anion/cation exchange membranes (AEM/CEM) and these were confirmed through contact angle/Chronopotentiometry/AFM/EDX. Sluggish potential rise (Galvanostatic mode) in Chronopotentiometric analysis indicated diffusion limiting transport of organic acids influenced AEM resistance. XRD and EDX analysis indicated the presence of salt hydrates/ions (Ca2 +/Fe3 +) over CEM justifying the resistance buildup due to adsorption of multivalent metal ion(s) and salts.