Mohsen Abbasi

In this study, the possibility of preparing fresh water through the environmentally friendly process of hybrid electrodialysis (ED)-reverse electrodialysis (RED) has been investigated. Therefore, the process performance has been evaluated with regard to both desalination and energy generation. Besides, the process has been modeled with real and synthetic concentrated brine with high salinity of up to 200000 ppm from Persian Gulf sea water and synthetic and real brackish water with the salinity of up to 7240 ppm from rivers in Bushehr province, Iran. Results demonstrated that the RED system was capable of generating the energy needed to desalinate brackish water with the salinity of less than 1000 ppm, while for higher salinities, an extra amount of electrical energy is required. It was also revealed that the best desalination performance (salt removal percentage) for brackish water with initial concentration of 1000, 2000 and 4000 ppm was 42, 53 and 52 %, respectively. Moreover, due to high level of salinity along with the presence of a variety of minerals in river waters, the rate of electricity production and desalination was less than that of the synthetic water samples on a pilot scale; e.g., for the Mond River with an initial salinity of 2690 ppm, the salinity reduction was around 27.17 %.