Patent ID: 8329040
Filing Date: 2012-12-11
Classification: C02F

Abstract:
1. A method for removing ammonia nitrogen in coking wastewater comprises: Step (1): introducing coking wastewater into a reaction pool; adding magnesium and phosphate into the pool with the mole ratio of magnesium:phosphate:ammonia nitrogen=0.8-1.5:0.7-1.2:1.0; then, adding sodium hydroxide to regulate the PH of the mixture to 9.0-10.5; separating a supernatant and a precipitate after proper agitation and natural precipitation; Step (2): dehydrating the precipitate in Step (1) and then adding alkaline fly ash to a dehydrated precipitate with the weight ratio of MAP:AFA=10:1-4; adding water to the mixture and stirring it, then decomposing it with heating; Step (3): absorbing an ammonia gas produced in Step (2) with acidic solution.