The last 40 years have seen a steady growth in electromembrane processes for industrial-scale applications. They have been used in water processing, preparation of ultrapure water, and management of effluents from the mining, hydrometallurgy, pulp & paper, and pharmaceutical industries.
Recently, electromembrane processes have been applied for blue energy (salinity gradient) production, fuel cells, dairy applications, chromic acid recovery, organic acid separation and recovery, synthesis of chemicals such as ionic liquids, extraction of water-soluble organic acids, salt separation from mixtures in organic solutions, separation of valuable ions from wastewater, demineralisation of sugar and amino acids, and so on. Modern industries like pharmaceuticals or chemicals, biotechnology and energy-related sectors use electromembrane processes widely.
However, the early euphoria of their applications has turned to a more mature and rational way of thinking. Available ion-exchange membranes and electromembrane processes still have severe technical and commercial limitations.
The main reason for this phenomenon is the shortage of knowledge on the processes and not completely satisfactory properties of available materials. The latter includes poor selectivity at high ion concentration, deterioration of membrane properties, high costs, and problems with membrane mechanical and chemical stability.
To this end, this Special Issue of Desalination is dedicated to electromembrane processes. The Guest Editors – Nalan Kabay at Ege University in Turkey, and Marek Bryjak at Wroclaw University of Technology in Poland – asked a group of recognised experts to give their opinions on this topic. The resulting Special Issue contains 18 contributions dealing with fundamentals, materials, applications, and new electromembrane processes.
The main aim of this Special Issue is to show the desalination community that electromembrane processes are still in the developing stage. New separation materials are available on the market, and new system configurations as well as entirely new processes are being introduced. It seems that hybrid and integrated processes offer an excellent opportunity for application of electromembrane processes in desalination and other applications.