Abstract: A fluoroberyllium borate non-linear optical single crystal is represented by a molecular formula of MBe2BO3F2, wherein M is Rb or Cs. The crystal can be grown by the flux method comprising the steps of mixing a fluoroberyllium borate compound and a flux in proportion, heating the mixture up to 750-800° C., keeping at this temperature and then cooling it to the temperature of 2-10° C. above the saturating point to obtain a fluoroberyllium borate solution at high temperature; putting the seed crystal fixed on the end of a crystal hanging bar into the fluoroberyllium borate solution at high temperature, rotating the crystal hanging bar, cooling the melt solution to its saturating point, then cooling it again slowly, pulling the obtained crystal out of the solution surface, cooling it to room temperature, then obtaining the present fluoroberyllium borate non-linear optical crystal.

Abstract: A precipitation device comprises a precipitation element disposed within a vessel and configured to define a precipitation zone and a solid-liquid separation zone between the precipitation element and the vessel, the precipitation zone configured to receive a first stream of saline liquid and to precipitate solids from the saline liquid, the solid-liquid separation zone configured to settle the solids by gravity, and an exit port located in an upper portion of the vessel and configured for exit of a second stream of liquid of lower salinity than the first stream, wherein a ratio of a diameter of the vessel to a diameter of the precipitation element ranges from about 1.5 to about 2.8. Associated system and method are also provided.

Abstract: A desalination system comprises an electrical separation device configured to receive and ionize a first stream for desalination and a crystallization device. The crystallization device is configured to provide a second stream to the electrical separation device to carry away ions from the first stream, and defining a crystallization zone for facilitating precipitation of the ions and a solid-liquid separation zone in fluid communication with the crystallization zone for separation of the precipitate. A desalination method is also presented.

Abstract: A method for removing ionic species from a desalination unit, comprises: (a) circulating a wash stream in a closed loop comprising a desalination unit and a precipitation unit, the wash stream flowing at a linear velocity of at least 5 cm/second through the desalination unit, the wash stream becoming more saline after passage through the desalination unit; and (b) removing a portion of calcium sulfate from the wash stream by precipitation in the precipitation unit to obtain a supersaturation degree of calcium sulfate in the wash stream entering the desalination unit in a range of from about 1.0 to about 3.0.

Abstract: A beryllium borate fluoride salt nonlinear optical crystal is represented by molecule formula Mbe2BO3F2, wherein M is Rb or Cs. The crystal is grown by melt salt method, comprising the following step, mixing beryllium borate fluoride salt with flux at appropriate ratio, rising to 750-800° C., and keeping at constant temperature, then cooling to 2-10° C. higher than saturated temperature to obtain a elevated solution; putting seed crystal on seed crystal pole into the elevated solution, rotating the seed crystal pole, cooling to saturated temperature, and then cooling slowly; raising the obtained crystal above liquid level and cooling to room temperature, then obtaining the present nonlinear optical crystal. The crystal has nonlinear optical effect, broad transmittance wave, adsorption edge of ultraviolet lower to 150 nm, doesn't deliquesce, isn't soluble to diluted hydrochloric acid and nitric acid, and has good chemical resistance.