Exceptionally high-rate nitrification in sequencing batch reactors treating high ammonia landfill leachate.
The nitrogen removal capacity of a suspended culture system treating mature landfill leachate was investigated. Leachate containing high ammonium levels of 300-900 mg N/L was nitrified in a bench scale sequencing batch reactor. Leachate from four different landfills was treated over a two year period for the removal of nitrogen. In this time, a highly specific nitrifying culture was attained that delivered exceptionally high rates of ammonia removal. No sludge was wasted from the system to increase the throughput and up to 13 g/L of MLSS was obtained. Settleability of the purely nitrifying biomass was excellent with SVI less than 40 mL/g, even at the high sludge concentrations. Nitrification rates up to 246 mg N/(L h) (5.91 g N/(L d)) and specific nitrification rates of 36 mg N/(gVSS h) (880 mg N/(gVSS d)) were obtained. The loading to the system at this time allowed complete nitrification of the leachate with a hydraulic retention time of only 5 hours. Following these successful treatability studies, a full-scale plant was designed and built at one of the landfills investigated.
Doyle
J
J
Advanced Wastewater Management Centre, University of Queensland, St Lucia, QLD 4072 Australia.
Watts
S
S
Solley
D
D
Keller
J
J
D000641:Ammonia / Q000302:isolation & purification*; D019149:Bioreactors; D009584:Nitrogen / Q000302:isolation & purification; D011793:Queensland; D012722:Sewage; D012989:Soil Pollutants / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods
D012722:Sewage; D012989:Soil Pollutants; D000641:Ammonia; D009584:Nitrogen