Efficient and stable nitritation and denitritation of ammonium-rich sludge dewatering liquor using an SBR with continuous loading

Influence of dissolved oxygen concentration and aeration time on nitrite accumulation in partial nitrification process

“…Therefore, the SBR partial nitrification can be divided into a few successive aerobic/anoxic phases, allowing a concurrent denitrification in the anoxic phase to avoid high nitrite accumulation imparting toxicity to the denitrification microorganisms. Indeed, the successive nitritation (aerobic) and denitrification (anoxic) was currently performed to treat the anaerobically-rejected wastewater containing around 1000 mg /L of NH 4 + -N in the laboratory-scale SBR process (Fux et al, 2006;Galí et al, 2007). Consistent with the results the partial nitritation along with simultaneous denitrification was successfully obtained when the total aeration time was designed as 3.5 and 4 h. respectively, for one typical cycle divided into three successive aerobic/anoxic subphases (Fux et al, 2006;Galí et al, 2007).…”

“…Resembling the trend of ammonium oxidation, the specific nitrite oxidation rate was limited at DO concentration of 0.5 mg/L, while for DO concentrations in the range of 2.0 to 6.0 mg/L it exhibited considerably higher values. Considering the DO concentration of ~ 1.0 mg O 2 /L used for the partial nitritation in the previous literatures (Ciudad et al, 2005;Galí et al, 2006;Fux et al, 2006), the nitrification kinetics and the consequent nitrite accumulation were specifically compared between the two DO concentrations of 0.8-1.5 (average 1.0) and 2.3-3.0 (average 2.5) mg O 2 /L. The VSS and initial ammonium concentrations were approximately set as 1200 g VSS/L and 275 mg N/L, respectively.…”

“…A representative example is the highly concentrated ammonia removal from the municipal landfill leachates, food processing wastewater, liquid wastes from animal production plants, condensates from fertilizer plants, and the supernatant from anaerobic sludge digesters, where the ammonia content can reach 600-1000 mg NH 4 + -N/ L Fux et al, 2006;Galí et al, 2006). The physico-chemical processes such as air and steam stripping are sometimes used for the nitrogen control from these types of wastewater (EPA, 1993).…”

“…Aiming at lowering the oxygen demand and reducing or avoiding organic substrate requirement, the newly developed processes are essentially based on partial nitrification of ammonium to nitrite (Galí et al, 2006;Fux et al, 2002;Mosquera-Corral, et al, 2005;Ciudad et al, 2005). To achieve the shortcut of nitrate formation, the potential strategies for the stable nitrite accumulation include the control of operating variables such as pH, hydraulic retention time (HRT), solid retention time (SRT), dissolved oxygen (DO) concentration, temperature (Ruiz et al, 2003;Kim et al, 2006;Tseng et al,1998;Bougard et al, 2006), and the screening of different reactor configurations such as SHARON reactor and sequencing batch reactor (SBR) (Fux et al, 2006;Galí et al, 2006;Antileo et al, 2006;Chuang et al, 2007). The control of an appropriate DO concentration is one of the most practical strategies to achieve nitrification via nitrite.…”

Biological nitrogen removal over nitritation/denitritation using phenol as carbon source

“…Other advantages of this process are a biological nitrogen reduction rate 63% higher than the conventional one, less biomass production and 40% reduction of the heterotrophic carbon demand (Phillips et al, 2002;Fux and Siegrist, 2004;Fux et al, 2006).…”