Chemical conversions of salt concentrates from desalination plants

Disposal of the desalination blow-down to the sea has detrimental affects t o the benthic environment. The blow-down consists of highly concentrated sa lts. This work proposes an environmentally beneficial process for the produ ction of some chemicals from the salt concentrates. The process involves a series of chemical reactions to convert the NaCl into Na2CO3, NaHCO3 and NH 4Cl. In the initial investigations using a batch gas bubbler, optimum tempe rature 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 a nalyses and development are needed. This work has shown preliminary indicat ions of the feasibility of protecting the environment by utilizing the salt concentrates from desalination plant for chemicals production.