Simultaneous nitrification and denitrification in bench-scale sequencing batch reactors

Simultaneous nitrification and denitrification in step feeding biological nitrogen removal process

“…At this DO concentration simultaneous nitrification and denitrification did not happen in the reactor. When the DO concentration was 0.5 mg/L the rate of NO x -N formation was 0.57 times than that of ammonia decay, which was corresponded well with the results of the Munch et al (1996). In this research the specific relationship of DO concentration and SND was proposed.…”

Removal of Nitrogen and COD from Reclaimed Water during Long-Term Simulated Soil Aquifer Treatment System under Different Hydraulic Conditions

“…Denitrification is usually considered as an anaerobic process. However, investigations have demonstrated that denitrification also take place in an aerobic environment, i.e., canals, ponds, soils, and activated sludge [40,41]. Specific bacteria [23,29] as well as some fungi have also been isolated those are able to carry out denitrification under aerobic conditions [42].…”

“…At the end of the third experimental year, soils in both columns were sampled at various depths from the soil surface (5,20,40,50,60,70 and 90 cm) to analyze the microorganism community. After sampling, 1 g soil was added in 99 mL of sterile water and the mixture was shaken for 30 min (at the rate of 170 r/min) at room temperature of 25 ± 0.5 • C. One milliliter of the soil suspension was then diluted serially (ten-fold) and used in the estimation of the amount of bacteria (denitrifying bacteria, nitrifying and nitrite bacteria) and fungi by standard spread-plate dilution method, in triplicate.…”

Efeitos do tempo de aeração no desempenho de reator de leito estruturado e aeração intermitente usado para remoção de matéria orgânica e nitrogênio de efluente de reator UASB

“…Existem algumas vantagens dos sistemas que operam com NDS em relação aos sistemas de remoção de nitrogênio convencionais como: menos unidades de tratamento; as condições de operação são mantidas constantes sem precisar de equipamentos de monitoramento e de controle entre a zona aerada e a zona anóxica; redução dos custos operacionais; e menor demanda de oxigênio e de alcalinidade (do Canto et al, 2008;Münch et al, 1996).…”

“…Assim, os microrganismos nitrificantes se desenvolvem nas regiões externas do biofilme ou floco, e os microrganismos desnitrificantes em regiões internas, onde há menor concentração de OD. Há, ainda, relatos da existência de bactérias desnitrificantes aeróbias, bem como de nitrificantes heterotróficas em sistemas com NDS (Münch et al, 1996). Nesse sentido, diversas estratégias de aeração foram testadas por do Canto et al (2008).…”