REMOVAL OF NUTRIENTS IN WASTE-WATER BY USING MAGNESIUM SALTS

The removal of ammonia nitrogen and phosphorus from wastewater by prec ipitating out with magnesium sails was showed. Factors of pH, reaction time, N/P ratio, and dissolution test were investigated to find optim al conditions for magnesium ammonium phosphate (MAP) formation. The in vestigated conditions were also applied to toxic industrial wastewater . SEM and EDS analyses indicated that the precipitate was magnesium am monium phosphate that was fine crystals of Mg and P compounds. The rem oval of ammonia and phosphorus increased with pH up to 10.5 where 82.6 % and 97% of ammonia nitrogen and phosphorus were removed. It was foun d that minimum 10 minutes reaction was required for the nutrients remo val. However, a small amount of phosphorus dissolved after 60 minutes. Ammonia nitrogen was well removed at one mole to two moles of magnesi um. But at doses higher than two moles of magnesium, ammonia nitrogen increased due probably to the decreased pH. Bittern and sea water prov ed to be excellent coagulants for nutrient removal from industrial was tewater. The comparative study of different magnesium sources showed t hat bittern was the most efficient as 72% 99% of ammonia and phosphoru s, respectively, were removed.