FRESHWATER SUPPLY FOR SHIPS DESALINATED BY METHOD OF ELECTRODIALYSIS
For the purpose of freshwater supply for ships, we have explored the desalination process of sea water by electrodialysis. From the analysis of the obtained results, the desalination process of the Black Sea water by electrodialysis has been explored. The average salt content of the Black Sea water is 15-16 g/l, and the global ocean water – 35 g/l, while the salt content in water from the Baltic Sea is 5.77 g/l. The Black Sea water was diluted with fresh water up to a concentration of 5.77 g/l.
Electrodalysis is the most effective method for desalination of natural waters with low salinity. So, we have taken water equivalent
to salt water content of the Baltic Sea water. Desalination of this water is effective and requires little energy. To reduce salt content of sea water, the separation was carried out on reverse osmosis membranes with a selectivity of 70%, and then the penetrant was separated by electrodialysis. Every 5 minutes, the solution loses 55.8% of salt. During the treatment (45 min), water is desalinated up to a concentration of 51.2 mg/l, and it can be used for industrial (technical) or household purposes. Calculation have shown that the selectivity of membranes during desalination was 99.11%.
As a result, on the basis of theoretical and experimental studies of seawater desalination by electrodialysis, there have been developed the principal circuits of the system of environmental safety of ballast water and water treatment facilities in the port, for environmental safety of ballast water and for obtaining industrial water.