Application of foam separation method for removal of alkaline earth metal ions from solution

Abstract

Abstract Foam separation was used to separate dissolved alkaline earth metal ions from aqueous solution. The mechanism is based on anionic surfactant adsorption onto the bubbles generated in the aqueous alkaline earth metal solution. The negatively charged bubbles rise while adsorbing the positive metal ions and change to foam at the surface. The foam in the glass tube drains excess water as it rises and is finally turned into dry foam. The foam separation method with sodium decyl sulfate (SDeS) (8\u202fmmol\u202fL−1, below the critical micelle concentration (CMC)) was used to remove alkaline earth metal (Mg, Ca, and Sr) chlorides in the respective systems. The initial concentrations of the surfactant and alkaline earth metal chloride were 8\u202fmmol\u202fL−1 (below the CMC) and 2.5\u202fmmol\u202fL−1 in 250\u202fmL of solution, respectively. The results showed that the removal rate in the one-component alkaline earth metal system increased with increasing atomic number: Mg (46%)