Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. S...Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen （DO） concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate （NAR） was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate （OLR）, COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration （0.5 mg·L^-1） and maintained high OLR （4.0 kg COD·m^-3·d^-1）. The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index （SVI） of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments.展开更多
The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average amm...The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.展开更多
A novel system coupling an up-flow anaerobic sludge blanket(UASB) and sequencing batch reactor(SBR) was introduced to achieve advanced removal of organic and nitrogen from ammonium-rich landfill leachate. UASB could r...A novel system coupling an up-flow anaerobic sludge blanket(UASB) and sequencing batch reactor(SBR) was introduced to achieve advanced removal of organic and nitrogen from ammonium-rich landfill leachate. UASB could remove 88.1% of the influent COD at a volumetric loading rate of 6.8 kg COD·m-3·d-1. Nitritation–denitritation was responsible for removing 99.8% of NH+4-N and 25% of total nitrogen in the SBR under alternating aerobic/anoxic modes. Simultaneous denitritation and methanogenesis in the UASB enhanced COD and TN removal, and replenished alkalinity consumed in nitritation. For the activated sludge of SBR, ammonia oxidizing bacteria were preponderant in nitrifying population, indicated by fluorescence in situ hybridization(FISH) analysis. The Monod equation is appropriate to describe the kinetic behavior of heterotrophic denitrifying bacteria,with its kinetic parameters determined from batch experiments.展开更多
The influence of main process parameters on simultaneous nitrification and denitrification （SND） in a sequencing batch reactor （SBR） were investigated while treating actual municipal sewage. The influent average c...The influence of main process parameters on simultaneous nitrification and denitrification （SND） in a sequencing batch reactor （SBR） were investigated while treating actual municipal sewage. The influent average concentration of CODcr and total nitrogen was 350mg-L-l and 35mg.L-l. The experiment indicated the following four operation control strategies： （1） When operation cycle was 6 hours, oxidation of organic pollutants and simultaneous nitrification and denitrification could well completed in the SBR reactor; （2） TN removal rate could be increased significantly, 40% higher than traditional SBR processes when idle period was set between influent and aeration; （3） The time of idle period could affect simultaneous nitrification and denitrification and the best time is 30 minutes; （4） Increase of sludge organic load may improve TN removal efficiency, but NH3-N removal efficiency declines.展开更多
The use of the reverse osmosis （RO） process, for refining secondary or tertiary effluent from plants treating domestic wastewater, is rapidly increasing. However, the disposal of the RO reject water poses a problem ...The use of the reverse osmosis （RO） process, for refining secondary or tertiary effluent from plants treating domestic wastewater, is rapidly increasing. However, the disposal of the RO reject water poses a problem due to the presence of very high concentrations of salts, metals, and nutrients in it. This paper contains results of a bench-scale study aimed at reducing nutrients from RO-discarded streams utilizing a sequential bioreactors system, under partial aerobic and anoxic conditions. The tests were performed on synthetic wastewater resembling RO-reject water of an operating treatment plant, with glucose, methanol or acetate added to the water as sources of carbon. Study results indicate that the RO process removed about 50-60% of the total nitrogen and 50% of the phosphate; it reduced chemical oxygen demand （COD） by 79 to 82%, and affected no change in the metal concentrations. A clear cut removal preference for any one of the external carbon sources was not observed, although a slight advantage of glucose and methanol was recorded. The process maintained about 20% of the rector volume in the anoxic environment.展开更多
基金the National Key Project of Scientific and Technical Supporting Program of Ministry of Science and Technology ofChina(2006BAC19B03)Academic Human Resources Development in Institutions of Higher Leading under the Jurisdiction ofBeijing Municipalitythe Specialized Research Fund for the Doctoral Program of Higher Education of China(20060005002).
文摘Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen （DO） concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate （NAR） was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate （OLR）, COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration （0.5 mg·L^-1） and maintained high OLR （4.0 kg COD·m^-3·d^-1）. The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index （SVI） of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments.
基金National Natural Science Foundation of China(NO.50521140075)
文摘The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.
基金Supported by the National Natural Science Foundation of China(51168028,51168027)Science and Technique Foundation Project for Youth of Gansu Province(1107RJYA279)
文摘A novel system coupling an up-flow anaerobic sludge blanket(UASB) and sequencing batch reactor(SBR) was introduced to achieve advanced removal of organic and nitrogen from ammonium-rich landfill leachate. UASB could remove 88.1% of the influent COD at a volumetric loading rate of 6.8 kg COD·m-3·d-1. Nitritation–denitritation was responsible for removing 99.8% of NH+4-N and 25% of total nitrogen in the SBR under alternating aerobic/anoxic modes. Simultaneous denitritation and methanogenesis in the UASB enhanced COD and TN removal, and replenished alkalinity consumed in nitritation. For the activated sludge of SBR, ammonia oxidizing bacteria were preponderant in nitrifying population, indicated by fluorescence in situ hybridization(FISH) analysis. The Monod equation is appropriate to describe the kinetic behavior of heterotrophic denitrifying bacteria,with its kinetic parameters determined from batch experiments.
文摘The influence of main process parameters on simultaneous nitrification and denitrification （SND） in a sequencing batch reactor （SBR） were investigated while treating actual municipal sewage. The influent average concentration of CODcr and total nitrogen was 350mg-L-l and 35mg.L-l. The experiment indicated the following four operation control strategies： （1） When operation cycle was 6 hours, oxidation of organic pollutants and simultaneous nitrification and denitrification could well completed in the SBR reactor; （2） TN removal rate could be increased significantly, 40% higher than traditional SBR processes when idle period was set between influent and aeration; （3） The time of idle period could affect simultaneous nitrification and denitrification and the best time is 30 minutes; （4） Increase of sludge organic load may improve TN removal efficiency, but NH3-N removal efficiency declines.
文摘The use of the reverse osmosis （RO） process, for refining secondary or tertiary effluent from plants treating domestic wastewater, is rapidly increasing. However, the disposal of the RO reject water poses a problem due to the presence of very high concentrations of salts, metals, and nutrients in it. This paper contains results of a bench-scale study aimed at reducing nutrients from RO-discarded streams utilizing a sequential bioreactors system, under partial aerobic and anoxic conditions. The tests were performed on synthetic wastewater resembling RO-reject water of an operating treatment plant, with glucose, methanol or acetate added to the water as sources of carbon. Study results indicate that the RO process removed about 50-60% of the total nitrogen and 50% of the phosphate; it reduced chemical oxygen demand （COD） by 79 to 82%, and affected no change in the metal concentrations. A clear cut removal preference for any one of the external carbon sources was not observed, although a slight advantage of glucose and methanol was recorded. The process maintained about 20% of the rector volume in the anoxic environment.
