REMOVAL OF AMMONIA COMPOUNDS FROM AQUEOUS SOLUTIONS AND WASTE WATER
The analysis of methods for removing ammonia molecules and ammonium ions from aqueous solutions and wastewaters is made. The dependences on the pH of the solution of the relative fraction of NH4+ ions and ammonia molecules NH3·H2O bound to water have been theoretically substantiated and experimentally confirmed (by potentiometric method). The optimal pH values ??of the solution were found, at which, in the presence of magnesium ions and HPO4-2 hydrogen phosphate, the most complete removal of ammonia molecules and NH4+ ions from an aqueous solution in the form of magnesium ammonium phosphate occurs. The sequence of reagents introduction to water is determined, the character of the dependence of the residual concentration of NH3 molecules over the MgNH4PO4 precipitate on the pH of the solution is shown. The maximum pH value (pH <10) is theoretically substantiated, above which the solubility of magnesium ammonium phosphate becomes higher than the solubility of magnesium phosphate with the transition of NH3 molecules back into solution or treated waste water.