Ammonia slip mitigation systems and methods

A method for removing ammonia from a condensate, the method comprising the steps of:

• introducing a flue gas to a direct contact cooler, the direct contact cooler configured to reduce a temperature of the flue gas, the flue gas comprising ammonia;
• contacting the flue gas with a water feed in the direct contact cooler to produce a cooled flue gas and the condensate, where the water feed flows countercurrent to the flue gas, where the water feed comprises water, where ammonia in the flue gas is absorbed into the water of the water feed, where the condensate comprises water and ammonia;
• introducing the condensate to an ammonia stripper, the ammonia stripper configured to separate ammonia from the water;
• contacting the condensate with an air feed to produce an air product and a wastewater, where the air feed flows countercurrent to the condensate, where the air feed comprises air, where the ammonia transfers from the condensate to the air of the air feed to produce the air product, where the wastewater comprises less than 5 ppm ammonia;
• introducing the wastewater to a treatment unit to produce a treated water, the treatment unit configured to modify the pH of the wastewater, where the pH of the wastewater is in a range of 10.5 to 11;
• introducing a carbonic acid feed to the treatment unit, where the carbonic acid feed comprises carbonic acid;
• and
• contacting the wastewater with the carbonic acid feed in the treatment unit to produce the treated water, where the ammonia in the wastewater reacts with the carbonic acid in the carbonic acid feed to produce ammonium bicarbonate, where the carbonic acid in the carbonic acid feed dissociates to produce hydrogen ions which reduce the pH of the treated water to a range of 7 to 7.5.