| 1. |
- Cema, Grzegorz, et al.
(författare)
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Nitrogen removal rates at a technical-scale pilot plant with the one-stage partial nitritation/Anammox process.
- 2006
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 54:8, s. 209-217
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Tidskriftsartikel (refereegranskat)abstract
- Traditional nitrification/denitrification is not suitable for nitrogen removal when wastewater contains high concentrations of ammonium nitrogen and low concentrations of biodegradable carbon. Recently, a deammonification process was developed and proposed as a new technology for treatment of such streams. This process relies on a stable interaction between aerobic bacteria Nitrosomonas, that accomplish partial nitritation and anaerobic bacteria Planctomycetales, which conduct the Anammox reaction. Simultaneous performance of these two processes can lead to a complete autotrophic nitrogen removal in one single reactor. The experiments where nitrogen was removed in one reactor were performed at a technical-scale moving-bed pilot plant, filled with Kaldnes rings and supplied with supernatant after dewatering of digested sludge. It was found that a nitrogen removal rate obtained at the pilot plant was 1.9 g m(-2) d(-1). Parallel to the pilot plant run, a series of batch tests were carried out under anoxic and aerobic conditions. Within the batch tests, where the pilot plant's conditions were simulated, removal rates reached up to 3g N m(-2) d(-1). Moreover, the batch tests with inhibition of Nitrosomonas showed that only the Anammox bacteria (not anoxic removal by Nitrosomonas) are responsible for nitrogen removal.
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| 2. |
- Szatkowska, Beata, et al.
(författare)
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A one-stage system with partial nitritation and Anammox processes in the moving-bed biofilm reactor
- 2007
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 55:8-9, s. 19-26
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Tidskriftsartikel (refereegranskat)abstract
- The ability of bacterial cultures to create biofilm brings a possibility to enhance biological 0 0 wastewater treatment efficiency. Moreover, the ability of Anammox and Nitrosomonas species to grow within the same biofilm layer enabled a one-stage system for nitrogen removal to be designed. Such a system, with Kaldnes rings as carriers for biofilm growth, was tested in a technical pilot plant scale (2.1 m(3)) at the Himmerfjarden Waste Water Treatment Plant (WWTP) in the Stockholm region. The system was directly supplied with supernatant originating from dewatering of digested sludge containing high ammonium concentrations. Nearly 1-year of operational data showed that during the partial nitritation/Anammox process, alkalinity was utilised parallel to ammonium removal. The process resulted in a small pH drop, and to its relationship with conductivity was found. The nitrogen removal rate for the whole period oscillated around 1.5g N m(-2) d(-1) with a maximum value equal to 1.9 g N m(-2) d(-1). Parallel to the pilot plant experiment a series of batch tests were run to investigate the influence on removal rates of different dissolved oxygen 4, conditions and addition of nitrite. The highest nitrogen removal rate (5.2 g N m(-2) d(-1)) in batch tests was obtained when the Anammox process was stimulated by the addition of nitrite. In the simultaneous partial nitritation and Anammox process, the partial nitritation was the rate-limiting step.
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| 3. |
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| 4. |
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| 5. |
- Szatkowska, Beata, et al.
(författare)
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Combined partial nitritation and Anammox biofilm system as a sustainable solution for supernatant treatment
- 2007
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Ingår i: Water Practice and Technology. - 1751-231X. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Nowadays, as the effluent water regulations become more stringent, there is a need to treat wastewater in the most efficient manner and according to sustainability principles. One of the possibilities to meet this challenge is treatment of side streams, which are usually returned to the main influent of Wastewater Treatment Plants (WWTP) increasing the total load. Following processes occurring in natural ecosystems a new biological technology - combination of partial nitritation and Anammox processes - for treatment of nitrogen-rich supernatant coming from digested sludge dewatering has been developed. The first stage of the process is an oxidation of half of the ammonium to nitrite (partial nitritation process). The following stage - Anammox process - is an anaerobic oxidation of ammonium and nitrite nitrogen to dinitrogen gas. The process has been successfully tested in a technical-scale pilot plant with a continuous supply of supernatant at Himmerfjärden WWTP. Kaldnes rings were provided for biofilm growth. Almost two-year experiences in operation of the two-stage process have been presented in this paper. The results showed that a proper adjustment of dissolved oxygen (DO) concentration in the bulk liquid and a pH value drop in the partial nitritation reactor is essential to obtain the ammonium-to-nitrite ratio (NAR) in the effluent close to 1.3 as required for the Anammox process. It took four months to recover the Anammox bacteria activity after NO2-N inhibition.
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| 6. |
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| 7. |
- Szatkowska, Beata, et al.
(författare)
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Influence of dissolved oxygen concentration on deammonification process performance
- 2004
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Ingår i: Integration and optimisation of urban sanitation systems. - 9172836644 ; , s. 121-131
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Partial nitrification together with Anammox process (deammonification) is a new method fornitrogen removal from wastewater, which nowadays is widely studied in Europe. Compared toconventional nitrification/denitrification, this method saves 100% of the required organic carbonsource and over 60% of the required oxygen. This leads to a reduction of operational costs of 90%.The deammonification process was successfully tested on a laboratory-scale pilot plant at RoyalInstitute of Technology (KTH) in Sweden for over 2 years. Two reactors of pilot plant were filledwith Kaldnes rings as a biofilm carrier and supplied with a supernatant from dewatering of thedigested sludge at the Bromma Wastewater Treatment Plant (WWTP). For the stable and efficientprocess performance a suitable values of many parameters as dissolved oxygen, pH, temperature,NO2-N and NO3-N concentration should be assured. This article presents an evaluation of theinfluence of dissolved oxygen (DO) on the deammonification process efficiency. Analysis of eightmonths operation of pilot plant proved that high N-removal efficiency of second reactor (Anammox)is assured by proper NO2-N/NH4-N ratio in the effluent from the first reactor depending on DOconcentration. To estimate influence of DO concentration on reaction rates during the Anammoxprocess several batch tests were performed. The highest ammonium and nitrite removal rates wereobtained for DO concentration amounted to 0.2÷0.4 mg O2/l. This is in agreement with theobservations from laboratory-scale pilot plant, when the best results for Anammox processefficiency took place under similar oxygen conditions. A linear correlation between inorganicnitrogen removal and conductivity in the batch tests proved that conductivity could be a suitableparameter for a nitrogen removal process control.
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| 8. |
- Szatkowska, Beata, et al.
(författare)
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Monitoring Of Nitrogen Removal Processes By Use Of Conductivity Measurements : [Övervakning av kvävereduktionsprocesser med hjälp av konduktivitetsmätningar]
- 2004
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Ingår i: Vatten. - 0042-2886. ; 60:2, s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- A newly developed technology for nitrogen removal from ammonium-rich streams comprises two biological steps. In the first step, about half of the ammonium is oxidized to nitrite (partial nitritation) and in the second one, the remaining ammonium reacts with the formed nitrite into nitrogen gas (Anammox; anaerobic ammonium oxidation). The system was studied in a laboratory-scale pilot plant at the Royal Institute of Technology (KTH) and in a pilot plant located at the Himmerfjärden Wastewater Treatment Plant (WWTP). Both plants were supplied with ammonium-rich supernatant from digested sludge dewatering. Kaldnes rings were used as biofilm carriers. The process performance was closely monitored by analysis of different nitrogen fractions, COD, alkalinity and measurements of pH, oxygen concentration and temperature. Additionally, conductivity measurements were performed. It was found that conductivity is an excellent method to monitor the nitrogen removal processes. Such observation is based on the fact that the supernatant main salt is ammonium hydrogen carbonate, which further during the processes is converted to the carbon dioxide and nitrogen gas molecules. Theoretically calculated conductivity values were in good agreement with the experimental data. Conductivity turns out to be a reliable and Inexpensive method to evaluate different biological nitrogen removal processes used for separate treatment of supernatant.
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| 9. |
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| 10. |
- Szatkowska, Beata, et al.
(författare)
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Partial nitritation/Anammox and CANON Nitrogen removal systems followed by conductivity measurements
- 2007
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Ingår i: Integration and optimisation of urban sanitation systems. - 9789171788269 ; , s. 109-117
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The deammonification process is a new biological promising method for a separate treatment ofammonium-rich digester supernatant. Its application can significantly reduce the nitrogen load inWastewater Treatment Plants (WWTPs). The method is a two-step process and it can beaccomplished in two separate stages (partial nitritation and Anammox) or in a singe one (CANON).Both these systems were tested at pilot plants: the CANON process in a laboratory-scale plant whilepartial nitritation/Anammox in a technical-scale one. The pilot plants were filled with Kaldnes ringsas biofilm carriers and supplied with supernatant, coming from digested sludge dewatering at theBromma and Himmerfjärden WWTPs, Stockholm, Sweden. The supernatant main ions - ammoniumand hydrogen carbonate - were converted during the processes to carbon dioxide and nitrogen gasmolecules and therefore the process performance could be followed by conductivity measurements.The experiments proved that conductivity was an easy and simple method to monitor the nitrogenremoval processes. Moreover, the data from on-line conductivity instruments, installed in theAnammox reactor of the technical-scale pilot plant, showed great similarity with the manualmeasurements.
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