The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town (MUCT) process. Meanwhile the relation between optimal n...The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town (MUCT) process. Meanwhile the relation between optimal nitrate concentration (Nopt) and influent C/N ratio was evaluated, in which the influent chemical oxygen demand (COD) concentration was stabilized at (290±10)mg/L, the influent total phosphorus (TP) concentration was stabilized at (7.0±0.5)mg/L. The results indicated that: (1) the nitrate concentration in the main anoxic zone had an effect on denitrifying dephosphatation capability, and the average percentages of anoxic phosphorus uptake in total phosphorus uptake (ηa) increased with nitrate concentration increasing, i.e., increasing from 62.1% at 2.0 mg/L to 63.7%, 65.6%, 68.1%, and 72.3% at 2.2, 2.4, 2.6 and 2.8mg/L, respectively; (2) the Nopt as function of influent C/N ratio could be calculated by the equation: y=0.67x2-7.79x+22.21; the maximum percentages of anoxic phosphorus uptake in total phosphorus uptake (ηa,max) as function of the Nopt could be calculated by the equation: y=0.77-0.33e-(x/1.52). The Nopt was the important control parameter that must be optimized for operation of conventional biological nutrient removal activated sludge (BNRAS) system.展开更多
基金Water Pollution Control and Management of Science and Technology Majon Projects (No.2008ZX07207005)The Programs for Development of Science and Technology of Jilin Province of China (No.20071105)
文摘The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town (MUCT) process. Meanwhile the relation between optimal nitrate concentration (Nopt) and influent C/N ratio was evaluated, in which the influent chemical oxygen demand (COD) concentration was stabilized at (290±10)mg/L, the influent total phosphorus (TP) concentration was stabilized at (7.0±0.5)mg/L. The results indicated that: (1) the nitrate concentration in the main anoxic zone had an effect on denitrifying dephosphatation capability, and the average percentages of anoxic phosphorus uptake in total phosphorus uptake (ηa) increased with nitrate concentration increasing, i.e., increasing from 62.1% at 2.0 mg/L to 63.7%, 65.6%, 68.1%, and 72.3% at 2.2, 2.4, 2.6 and 2.8mg/L, respectively; (2) the Nopt as function of influent C/N ratio could be calculated by the equation: y=0.67x2-7.79x+22.21; the maximum percentages of anoxic phosphorus uptake in total phosphorus uptake (ηa,max) as function of the Nopt could be calculated by the equation: y=0.77-0.33e-(x/1.52). The Nopt was the important control parameter that must be optimized for operation of conventional biological nutrient removal activated sludge (BNRAS) system.
