Apparatus and Method for Treating Waste Water Containing Ammonium Salts

A waste water treatment apparatus for treating waste water containing ammonium salts that contains NH4+, SO4, Cl− and Na+, comprising:

• a pH adjustment unit, a first evaporation unit, a first solid-liquid separation unit, a second evaporation unit, and a second solid-liquid separation unit, which are connected sequentially,
• wherein the pH adjustment unit is configured to adjust the pH of the waste water to a value greater than 9 before evaporation is performed;
• the first evaporation unit is configured to treat the waste water by first evaporation, to obtain a first ammonia-containing vapor and a first crystal-containing concentrated solution;
• the first solid-liquid separation unit is configured to treat the first crystal-containing concentrated solution by first solid-liquid separation;
• the second evaporation unit is configured to treat the liquid phase obtained in the first solid-liquid separation unit by second evaporation, to obtain a second ammonia-containing vapor and a second crystal-containing concentrated solution;
• and
• the second solid-liquid separation unit is configured to treat the second crystal-containing concentrated solution by second solid-liquid separation.