Fouling of ion exchange membranes used in the electrodialysis reversal advanced water treatment: A review

Electrodialysis self-reversal (EDR) technology has attracted in the treatment of water for domestic and industrial uses. The self-reversal consists of a frequent reversal of the direction of current between the EDR-cell electrodes to combat fouling of ion exchange membranes (IEMs). Irrespective of the EDR self-cleaning processes, the role of natural organic matter and their complexing ability with metal ions on IEMs fouling is partially understood. The objective of this review is to identify the research gaps present in the elucidation of IEM fouling routes. The common IEMs’ foulants are identified, and several fouling mechanisms are briefly discussed. The effectiveness of self-cleaning mechanisms to reduce IEMs fouling is also be discussed. Dissolved organic carbon (DOC) possesses high chelation which forms metal complexes with di and trivalent cations found in water. The role of ternary complexes, e.g. M2+/3+–DOC and membrane surface, on membrane fouling via surface bridging, are also addressed. Finally, mitigation methods of IEMs membrane fouling are also discussed. [Display omitted] •Self–reversal in EDR fails some times to get rid of foulants.•Groundwater contains DOC–Ca2+ complexes alone with free Ca2+ ions.•Ternary DOC–Ca2+ –membrane complexes responsible for irreversible fouling in AEMs.