Assess of physical antiscale-treatments on conventional electrodialysis pilot unit during brackish water desalination

Electrodialysis for water desalination: A critical assessment of recent developments on process fundamentals, models and applications

“…In addition, the possibility of treating the concentrate stream (i.e. the one with highest scaling potential) of a batch ED unit by magnetic or ultrasonic field has been reported [154]. In particular, the magnetic field was applied to a part of the feeding line, while an ultrasonic bath was used as the concentrate tank.…”

Innovations in electromembrane processes

“…When the polarity changes, direction of ion migration changes, which tears off the growing deposits and the membrane electric resistance is restored. Novel methods of scaling avoidance are being developed: performed a single-pass electrodialysis in a such manner that residence time of majority of the particles travelling the concentrate compartment is smaller than the crystallization induction time, which prohibits the creation of crystal nuclei inside the ED module [19]; application of pulsed electric field (PEF), which acts as cleaning-in place process [18,20]; application of external magnetic field, which disturbs the double ionic layer surrounding the colloidal particles and their zeta potentials by action of Lorentz forces exerted either on moving ions or on charged solid particlesthe result is the decreased nucleation rate [21]; application of ultrasonic field, which mechanism of action is still disputed [21]. Since the invention of the electrodialysis there has been a constant development in stack configuration, which resulted in creating new electromembrane processes: electrodialysis metathesis (EDM), electro-electrodialysis (EED), electrodialysis with bipolar membrane (EDBM); however, a lot of progress have been made with hybrid electromembrane processes: electrodeionization (EDI), which combines electrodialysis and ion exchange; membrane capacitive deionization (MCDI) and flow electrode capacitive deionization (FCDI), which combine electrosorption of porous carbon electrodes with ion-exchange membranes; electrochemical desalination, which combines electrochemical reactions with ion-exchange membranes; electrodialysis with ultrafiltration (EDUF) membrane, which combines electrodialysis with pressure-driven methods; and electrodialysis with liquid membranes.…”

A model-based analysis of electrodialysis fouling during pulsed electric field operation

“…The attachment and precipitation of organic and inorganic components on the membranes, the migration into the membranes and the clogging of the spacer channels can lead to a serious reduction in the process efficiency. A lot of research has been conducted to increase the fouling resilience of ED and this has given rise to a plethora of fouling prevention strategies which include the modification of ion-exchange membranes (IEMs) [1][2][3][4] the use of additives [5,6], the application of external force fields such as magnetic and ultrasonic fields [7] and improvements to the system design and operational conditions [8][9][10][11][12][13]. Some studies have shown that the fouling rate is heavily influenced by the flow rate and the electrical potential [14,15] and several strategies have been conceptualised to optimise both operational variables [12,13,[16][17][18][19][20][21].…”