| 摘要 |
In the regeneration in bicarbonate form of anion exchange resin exhausted by passage of water contg. anions, partic. nitrate ions, by treating the resins with an electrolyte contg. bicarbonate ions, improvement is that prior to treating with electrolyte contg. bicarbonate ions, the resin is treated with an electrolyte contg. chloride ions. The process allows removal of nitrate ions in waste waters and is simple, reliable and rapid and can be effected in modern appts. other ions can also be eliminated, e.g. sulphate ions. The electrolyte contg. chloride ions is a soln. of alkali(ne earth) metal chloride, ammonium chloride and/or HCl, at a concn. of 3-15 wt.%. The electrolyte contg. bicarbonate ions is a soln. of alkali metal and/or ammonium bicarbonate at a concn. of 3-10 wt.%, and is pref. a 2-6 wt.% soln. of alkali metal and/or ammonium carbonate satd. with CO2 or a 2-4 wt.% soln. of alkali metal and/or ammonium hydroxide satd. with CO2. |
