Desalination, Vol.139, No.1-3, 287-295, 2001
Chemical conversions of salt concentrates from desalination plants
Disposal of the desalination blow-down to the sea has detrimental affects to the benthic environment. The blow-down consists of highly concentrated salts. This work proposes an environmentally beneficial process for the production of some chemicals from the salt concentrates. The process involves a series of chemical reactions to convert the NaCl into Na2CO3, NaHCO3 and NH4Cl. In the initial investigations using a batch gas bubbler, optimum temperature of 22 degreesC and NH3/NaCl ratio of 1.2 were established. At these conditions the highest NaCl conversion of 82.2% was obtained. The economic benefits of the proposed process cannot be immediately evaluated. Further analyses and development are needed. This work has shown preliminary indications of the feasibility of protecting the environment by utilizing the salt concentrates from desalination plant for chemicals production.