The concept of anaerobic ammonium oxidation(ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile,th...The concept of anaerobic ammonium oxidation(ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite(CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will ac-celerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process.展开更多
The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments...The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor（SBR） activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride（NaCI） to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.展开更多
A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatment...A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen （TIN） loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 rag. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.展开更多
Excess nitrogenous compounds are detrimental to natural water systems and to human health. To completely realize autohy- drogenotrophic nitrogen removal, a novel 3-dimensional biofilm-electrode reactor was designed. T...Excess nitrogenous compounds are detrimental to natural water systems and to human health. To completely realize autohy- drogenotrophic nitrogen removal, a novel 3-dimensional biofilm-electrode reactor was designed. Titanium was electroplated with ruthenium and used as the anode. Activated carbon fiber felt was used as the cathode. The reactor was separated into two chambers by a permeable membrane. The cathode chamber was filled with granular graphite and glass beads. The cathode and cathode chamber were inhabited with domesticated biofilm. In the absence of organic substances, a nitrogen removal efficiency of up to 91% was achieved at DO levels of 3.42 ± 0.37 mg/L when the applied current density was only 0.02 mA/cm^2. The oxidation of ammonium in biofilmelectrode reactors was also investigated. It was found that ammonium could be oxidized not only on the anode but also on particle electrodes in the cathode chamber of the biofilm-electrode reactor. Oxidation rates of ammonium and nitrogen removal efficiency were found to be affected by the electric current loading on the biofilm-electrode reactor. The kinetic model of ammonium at different electric currents was analyzed by a first-order reaction kinetics equation. The regression analysis implied that when the current density was less than 0.02 mA/cm^2, ammonium removal was positively correlated to the current density. However, when the current density was more than 0.02 mA/cm^2, the electric current became a limiting factor for the oxidation rate of ammonium and nitrogen removal efficiency.展开更多
In this study,three sequential batch biofilm reactors(SBBRs)were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite(CANON)process under different aeration modes a...In this study,three sequential batch biofilm reactors(SBBRs)were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite(CANON)process under different aeration modes and dissolved oxygen(DO).Synthetic wastewater with 160-mg NH_(4)^(+)-N/L was fed into the reactors.In the continuously-aerated reactor,the efficiency of the ammonium nitrogen conversion and total nitrogen(TN)removal reached 80% and 70%,respectively,with DO between 0.8–1.0 mg/L.Whereas in the intermittently-aerated reactor,at the aeration/non-aeration ratio of 1.0,ammonium was always under the detection limit and 86% of TN was removed with DO between 2.0–2.5 mg/L during the aeration time.Results show that CANON could be achieved in both continuous and intermittent aeration pattern.However,to achieve the same nitrogen removal efficiency,the DO needed in the intermittently-aerated sequential batch biofilm reactor(SBBR)during the aeration period was higher than that in the continuously-aerated SBBR.In addition,the DO in the CANON system should be adjusted to the aeration mode,and low DO was not a prerequisite to CANON process.展开更多
基金Project supported by the National Hi-Tech Research and Develop-ment Program (863) of China (No. 2006AA06Z332)the Scienceand Technology Foundation for Key Project of Zhejiang Province (No2003C13005), China
文摘The concept of anaerobic ammonium oxidation(ANAMMOX) is presently of great interest. The functional bacteria belonging to the Planctomycete phylum and their metabolism are investigated by microbiologists. Meanwhile,the ANAMMOX is equally valuable in treatment of ammonium-rich wastewaters. Related processes including partial nitritation-ANAMMOX and completely autotrophic nitrogen removal over nitrite(CANON) have been developed,and lab-scale experiments proved that both processes were quite feasible in engineering with appropriate control. Successful full-scale practice in the Netherlands will ac-celerate application of the process in future. This review introduces the microbiology and more focuses on application of the ANAMMOX process.
基金The Hi_Tech Research and Development Program(863) of China(2004AA601020) the National Natural Science Foundation of China(No.50478047)andthe Open Grant of Beijing Key Laboratory
文摘The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor（SBR） activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride（NaCI） to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No. 2009ZX07423-003)
文摘A GAC-sand dual media filter （GSF） was devised as an alternative solution for drinking water treatment plant to tackle the raw water polluted by ammonium in place of expensive ozone-GAC processes or bio-pretreatments. The ammonium removal pathways and microbial community in the GSFs were investigated. The concentrations of ammonium, nitrite and nitrate nitrogen were monitored along the filter. Total inorganic nitrogen （TIN） loss occurred during the filtration. For 1 mg ammonium removal, the TIN loss was as high as 0.35 mg, DO consumption was 3.06 mg, and alkalinity consumption was 5.55 rag. It was assumed that both nitrification and denitrification processes occur in the filters to fit the TIN loss and low DO consumption. During the filtration, nitritation, nitrification and nitritation-anaerobic ammonium oxidation processes probably occur, while traditional nitrification and denitrification and simultaneous nitrification and denitrification processes may occur. In the GSFs, Nitrosomonas and Nitrospira are likely to be involved in nitrification processes, while Novosphingobium, Comamonadaceae and Oxalobacteraceae may be involved in denitrification processes.
基金supported by the Water Special Project(No.2009ZX07104 002)the Fundamental Research Funds for the Central Universities of China(No.CQDXWL2012-040)
文摘Excess nitrogenous compounds are detrimental to natural water systems and to human health. To completely realize autohy- drogenotrophic nitrogen removal, a novel 3-dimensional biofilm-electrode reactor was designed. Titanium was electroplated with ruthenium and used as the anode. Activated carbon fiber felt was used as the cathode. The reactor was separated into two chambers by a permeable membrane. The cathode chamber was filled with granular graphite and glass beads. The cathode and cathode chamber were inhabited with domesticated biofilm. In the absence of organic substances, a nitrogen removal efficiency of up to 91% was achieved at DO levels of 3.42 ± 0.37 mg/L when the applied current density was only 0.02 mA/cm^2. The oxidation of ammonium in biofilmelectrode reactors was also investigated. It was found that ammonium could be oxidized not only on the anode but also on particle electrodes in the cathode chamber of the biofilm-electrode reactor. Oxidation rates of ammonium and nitrogen removal efficiency were found to be affected by the electric current loading on the biofilm-electrode reactor. The kinetic model of ammonium at different electric currents was analyzed by a first-order reaction kinetics equation. The regression analysis implied that when the current density was less than 0.02 mA/cm^2, ammonium removal was positively correlated to the current density. However, when the current density was more than 0.02 mA/cm^2, the electric current became a limiting factor for the oxidation rate of ammonium and nitrogen removal efficiency.
基金This study was supported by the National Natural Science Foundation of China(Grant No.50608071)the Key Grant Project of Ministry of Education of China(Grant No.308020)+1 种基金Chongqing University Postgraduates’Science and Innovation Fund(No.200801A1A0180277)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20050611010).
文摘In this study,three sequential batch biofilm reactors(SBBRs)were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite(CANON)process under different aeration modes and dissolved oxygen(DO).Synthetic wastewater with 160-mg NH_(4)^(+)-N/L was fed into the reactors.In the continuously-aerated reactor,the efficiency of the ammonium nitrogen conversion and total nitrogen(TN)removal reached 80% and 70%,respectively,with DO between 0.8–1.0 mg/L.Whereas in the intermittently-aerated reactor,at the aeration/non-aeration ratio of 1.0,ammonium was always under the detection limit and 86% of TN was removed with DO between 2.0–2.5 mg/L during the aeration time.Results show that CANON could be achieved in both continuous and intermittent aeration pattern.However,to achieve the same nitrogen removal efficiency,the DO needed in the intermittently-aerated sequential batch biofilm reactor(SBBR)during the aeration period was higher than that in the continuously-aerated SBBR.In addition,the DO in the CANON system should be adjusted to the aeration mode,and low DO was not a prerequisite to CANON process.
