Aerobic ammonia-nitrogen oxidation during the treatment of hazardous waste leachate

The purpose of this work was to determine if an anaerobic/aerobic treatment process could effectively process leachate from a class I hazardous waste landfill. Initial treatment of the leachate was provided by fluidized bed granular activated carbon (GAC) anaerobic reactors with suspended growth aerobic reactors polishing the effluent. One of the primary purposes of the aerobic treatment phase was the biological removal of ammonia-nitrogen from the waste stream. Nitrification initially occurred in the second step of a two-stage aerobic treatment process. The two-stage process was subsequently dropped when complete nitrification was established in what was expected to be the carbonaceous first stage. A single-stage combined carbonaceous/nitrogenous oxidation process was used for the duration of the project.; Complete nitrification was established across this aerobic reactor with an efficiency of 98 percent. The ammonia-nitrogen concentration was oxidized to less than 1 mg/l in nine hours. The aerobic reactors were run as sequential batch reactors with an aeration time of 23 hours. The operating parameters in the reactors were nearly ideal for nitrification with a pH of 8.4 and temperature of 18{dollar}spcirc{dollar}C.