Approximate cost of the elimination of boron in desalinated water by reverse osmosis and ion exchange resins

Abstract An approximate cost of desalinated water treatment has been calculated to reduce the concentration of boron. The study is based on experimental data obtained in pilot plants working continuously with real water from a previous RO desalination. The results of the analysis should be taken as approximate, since on one hand experimentation in the pilot plant should be extrapolated to an industrial plant and on the other hand some of the costs included are estimates or theoretical. However, the analysis allows us to know the parameters that most contribute to the final cost of treated water. The results obtained were compared with different membranes and different commercial resins. The cost for the removal of boron at levels below the detection limit can be between 0.2 and 3.2 cent €/m 3 higher when membranes are used than when using resins. This is due mainly to the cost of reagents necessary to raise the pH. If the boron concentration is to be reduced to 0.5 mg/L, then the differences are reduced and the membrane process is the more economical. The cost of membrane treatment is between 0.1 and 1.2 cent €/m 3 less than treatment with resins.