Possibility of improvement of boiler water treatment process-ion exchange vs. reverse osmosis

Abstract

The boiler water in certain power plant is produced by chemical decarbonization, sand filtration, and ion exchange. Process ends with mixed bed ion exchange. The current boiler water treatment process is analyzed in terms of achieved water quality, quantity and quality of wastewater, and amount of chemicals needed. The main disadvantage of current process is consumption of large amount of chemicals. Ion exchange process could be replaced with the reverse osmosis, but pretreatment (decarbonization and filtration) should be retained. Since the permeate quality does not meet quality requirements, it would be advisable to use mixed bed ion exchange. If reverse osmosis is used, quantity of water that enters the treatment and wastewater would be for about 17.5 and 150% larger, respectively, but content of salt in wastewater would be about 20-30-fold less. Nevertheless, final decision on which technique to apply should be based on further economical considerations. © 2013 Desalination Publications.