| 1. |
- Atasoy, Merve, et al.
(författare)
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Bio-based volatile fatty acid production and recovery from waste streams: Current status and future challenges
- 2018
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 268, s. 773-786
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Forskningsöversikt (refereegranskat)abstract
- Bio-based volatile fatty acid (VFA) production from waste-stream is getting attention due to increasing market demand and wide range usage area as well as its cost-effective and environmentally friendly approach. The aim of this paper is to give a comprehensive review of bio-based VFA production and recovery methods and to give an opinion on future research outlook. Effects of operation conditions including pH, temperature, retention time, type of substrate and mixed microbial cultures on VFA production and composition were reviewed. The recovery methods in terms of gas stripping with absorption, adsorption, solvent extraction, electrodialysis, reverse osmosis, nanofiltration, and membrane contractor of VFA were evaluated. Furthermore, strategies to enhance bio-based VFA production and recovery from waste streams, specifically, in-line VFA recovery and bioaugmentation, which are currently not used in common practice, are seen as some of the approaches to enhance bio-based VFA production.
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| 2. |
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| 3. |
- Baresel, Christian, et al.
(författare)
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Hammarby Sjöstadsverk. Uppstart av Försöks- och Demonstrationsanläggningen för Framtidens Kommunala VA-Teknik
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sjöstadsverket är en unik resurs för att utveckla VA-forskning i Sverige och internationellt. Stockholm Vatten överlåter (1/1 2008) hela försöksanläggningen för fortsatt experimentell verksamhet inom VA-området till en FoU grupp ledd av IVL och KTH. Det primära målet är först att säkerställa kontinuiteten i driften och kostnader för detta ska täckas genom projektstöd från olika intressenter. Tanken är att all verksamhet skall finansierats genom olika projekt.Forskningsinriktningen kommer att beslutas av en FoU styrelse där finansiärerna sitter med. Tre huvudmål för drift av anläggningen har definierats: A. Utveckling och optimering av befintliga metoder och processkonfigurationer för resurseffektiv avloppsvattenrening. B. Utveckling av nya innovativa metoder och processkonfigurationer för förbättrad behandling av vattenfas samt sidoströmmar. C. Testning samt utvärdering av utrustningar för vattenreningsteknik, specifika komponenter och system med fokus på världsmarknaden. Relevanta projektförslag för svensk VA-teknik kan delas upp i åtta huvudområden: 1. Krav på ingående vatten, 2. Optimering av befintliga aeroba och anaeroba processer, 3. Kompletterande rening, 4. Processtyrning samt mätteknik, 5. Behandling av sidoströmmar, 6. Klimateffektiv behandlingsteknik, 7. Biogasproduktion, 8. Nya innovativa tekniker och processer. Från dessa huvudområden prioriterar Svenskt Vatten i samråd med ITT Flygt, NV och övriga FoU-styrelseledamöter vilka konkreta projekt som ska startas upp.
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| 4. |
- Cema, Grzegorz, et al.
(författare)
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A one-stage system with partial nitritation and Anammox processes in Rotating Biological Contactor (RBC) for treating landfill leachate
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Ingår i: Journal of Hazardous Materials. - 0304-3894 .- 1873-3336.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- One of the major aspects associated with landfilling of solid wastes is related to the discharge of leachate into environment. Leachates with high ammonium nitrogen content are generally difficult to effective treat in conventional biological treatment processes. Therefore, it brings a requirement of developing new processes and technologies. Additionally, treatment procedures must consider small flow rates of leachate. The Rotating Biological Contactor (RBC) is a good example of technology for treatment such wastewaters, because of its excellent shock and toxic loading capabilities, simple process control and low energy requirements. The main objective of the presented research was to investigate a simultaneous partial nitritation/Anammox process in the rotating biological contactor. For this purpose, the lab-scale reactor was fed with real landfill leachate from two municipal landfill sites in Gliwice and Zabrze (Poland). The reactor was highly loaded up to 7 g N m-2d-1 and it was possible to obtain the maximum inorganic nitrogen removal rate of 6.2 g N m-2d-1. Achieved results proved the possibility of efficient inorganic nitrogen removal by means of partial nitritation/ Anammox process in the temperature around 20°C.
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| 5. |
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| 6. |
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| 7. |
- Cema, Grzegorz, 1979-
(författare)
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Comparative study on different Anammox systems
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The legal requirements for wastewater discharge into environment, especially to zones exposed to eutrophication, lately became stricter. Nowadays wastewater treatment plants have to manage with the new rules and assure better biogenic elements’ removal, in comparison with the past. There are some well-known methods of diminishing concentrations of these compounds, but they are ineffective in case of nitrogen-rich streams, as landfill leachate or reject waters from dewatering of digested sludge. This wastewater disturbs conventional processes of nitrification-denitrification and raise necessity of building bigger tanks. The partial nitritation followed by Anaerobic Ammonium Oxidation (Anammox) process appear to be an excellent alternative for traditional nitrification/denitrification. The process was investigated in three different reactors – Membrane Bioreactor (MBR), Moving Bed Biofilm Reactor (MBBR) and Rotating Biological Contactor (RBC). The process was evaluated in two options: as a two-stage process performed in two separate reactors and as a one-stage process. The two-step process, in spite of very low nitrogen removal rates, assured very high nitrogen removal efficiency, exceeding even 90% in case of the MBBR. However, obtained results revealed that the one-step system is a better option than the two-step system, no matter, what kind of nitrogen-rich stream is taken into consideration. Moreover, the one-step process was much less complicated in operation. Performed research confirmed a hypothesis, that the oxygen concentration in the bulk liquid and the nitrite production rate are the limiting factors for the Anammox reaction in a single reactor. In order to make a quick and simple determination of bacteria activity, the Oxygen Uptake Rate (OUR) tests were shown as an excellent tool for evaluation of the current bacteria activity reliably, and without a need of using expensive reagents. It was also shown, that partial nitritation/Anammox process, could be successfully applied at temperatures much lower than the optimum value. Performed Fluorescent in situ Hybridization (FISH) analyses, proved that the Anammox bacteria were mainly responsible for the nitrogen removal process.
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| 8. |
- Cema, G., et al.
(författare)
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Deammonification in an aerobic Rotating Biological Contactor (RBC)
- 2008
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Ingår i: Int. Workshop Manage. Pollut. Emiss. Landfills Sludge. - 9780415433372 ; , s. 211-218
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Konferensbidrag (refereegranskat)abstract
- Leachate from landfills is a highly complex polluted wastewater. Landfill leachate with a high concentration of ammonium nitrogen is generally difficult to treat, efficiently. Furthermore, it can be very expensive when there is lack of an easily biodegradable carbon source. Combination of the nitrification/denitrification with the Anammox process can be a very attractive alternative. For the purpose of this study, a Rotating Biological Contactor (RBC) was used. The main objective of the research was to investigate the performance of the Anammox process that occurs together with heterotrophic denitrification in the same RBC. During the operation period the acclimation of biofilm to the Anammox process was successful at temperature not exceeding 20°C. Apparently, the process was not affected by a high concentration of nitrite up to 100 g NO2-N m-3 Additionally, it was shown that the Stover-Kincannon model could be used for description of the ammonium and nitrite removal rates.
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| 9. |
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| 10. |
- Cema, Grzegorz, et al.
(författare)
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Dissolved oxygen as a factor influencing nitrogen removal rates in a one-stage system with partial nitritation and Anammox process
- 2011
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 64:5, s. 1009-1015
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Tidskriftsartikel (refereegranskat)abstract
- A biofilm system with Kaldnes biofilm carrier was used in these studies to cultivate bacteria responsible for both partial nitritation and Anammox processes. Due to co-existence of oxygen and oxygen-free zones within the biofilm depth, both processes can occur in a single reactor. Oxygen that inhibits the Anammox process is consumed in the outer layer of the biofilm and in this way Anammox bacteria are protected from oxygen. The impact of oxygen concentration on nitrogen removal rates was investigated in the pilot plant (2.1 m(3)), supplied with reject water from the Himmerfjarden Waste Water Treatment Plant. The results of batch tests showed that the highest nitrogen removal rates were obtained for a dissolved oxygen (DO) concentration around 3 g O(2) m(-3). At a DO concentration of 4 g O(2) m(-3), an increase of nitrite and nitrate nitrogen concentrations in the batch reactor were observed. The average nitrogen removal rate in the pilot plant during a whole operating period oscillated around 1.3 g N m(-2)d(-1) (0.3 +/- 0.1 kg N m(-3)d(-1)) at the average dissolved oxygen concentration of 2.3 g O(2) m(-3). The maximum value of a nitrogen removal rate amounted to 1.9 g N m(-2)d(-1) (0.47 kg N m(-3)d(-1)) and was observed for a DO concentration equal to 2.5 g O(2) m(-3). It was observed that increase of biofilm thickness during the operational period, had no influence on nitrogen removal rates in the pilot plant.
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