Emissão de óxido nitroso de estação de tratamento de esgoto de lodos ativados por aeração prolongada - estudo preliminar Nitrous oxide emissions from an activated sludge wastewater treatment plant with prolonged aeration process - a preliminary study

Abstract

Nitrous oxide emissions from an activated sludge plant which serves a research institute in Rio de Janeiro city were estimated from six unit processes (grit tank, sand trap, aeration tank, secondary settling tank, sludge recirculation line and aerobic digester sludge tank) and also from the plant effluent. Total estimated annual flux was 3.2 x 10(4) g N2O yr-1 of which about 90% was from the aeration tank. Emission factors estimated from population served, wastewater flow and nitrogen load (conversion ratio) were 13 g N2O person-1 yr-1, 9.0 x 10-5 g N2O Lwastewater-1 and 0.14%.

Keywords

• nitrous oxide
• wastewater treatment
• activated sludge