| 1. |
- Andersson Chan, Anneli, 1971-, et al.
(författare)
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Increased nitrogen removal in existing volumes at Sundet wastewater treatment plant, Växjö
- 2014
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Ingår i: Water practice and technology. - : IWA Publishing. - 1751-231X. ; 9:2, s. 215-224
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Tidskriftsartikel (refereegranskat)abstract
- Many wastewater treatment plants need to improve their nitrogen removal due to stricter requirements and increasing loads. This often means larger bioreactor volumes, which can be very expensive and is sometimes impossible if space is limited. Therefore, there is a need for compact hybrid solutions that can increase capacity within existing volumes. Two full-scale demonstration projects using moving bed biofilm reactor (MBBR) technology has proven to be an efficient way to treat nitrogen in existing volumes at Sundet wastewater treatment plant in Växjö. Increased nitrification and denitrification capacity in parts of the main stream were demonstrated through the Hybas™ process, a combination of MBBR and activated sludge using the integrated fixed-film activated sludge technology. The ANITA™ Mox process, using autotrophic N-removal through anaerobic ammonium oxidation (anammox), provided high nitrogen removal for the sludge liquor. Data collected on-site for over a year are analyzed and compared with the performance of conventional treatment systems. These two full-scale demonstration projects have been a successful learning experience in identifying and correcting both process and operational issues, which may not have arisen at pilot scale. The set objectives in terms of nitrogen removal were met for both processes and design modifications have been identified that will improve future operation at Sundet WWTP.
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| 2. |
- Christensson, Magnus, et al.
(författare)
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Experience from start-ups of the first ANITA Mox Plants
- 2013
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 67:12, s. 2677-2684
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Tidskriftsartikel (refereegranskat)abstract
- ANITA (TM) Mox is a new one-stage deammonification Moving-Bed Biofilm Reactor (MBBR) developed for partial nitrification to nitrite and autotrophic N-removal from N-rich effluents. This deammonification process offers many advantages such as dramatically reduced oxygen requirements, no chemical oxygen demand requirement, lower sludge production, no pre-treatment or requirement of chemicals and thereby being an energy and cost efficient nitrogen removal process. An innovative seeding strategy, the 'BioFarm concept', has been developed in order to decrease the start-up time of new ANITA Moxinstallations. New ANITA Mox installations are started with typically 3-15% of the added carriers being from the 'BioFarm', with already established anammox biofilm, the rest being new carriers. The first ANITA Mox plant, started up in 2010 at Sjolunda wastewater treatment plant (WWTP) in Malmo, Sweden, proved this seeding concept, reaching an ammonium removal rate of 1.2 kgN/m(3) d and approximately 90% ammonia removal within 4 months from start-up. Thisfirst ANITA Mox plant is also the BioFarm used for forthcoming installations. Typical features of this first installation were low energy consumption, 1.5 kW/NH4-N-removed, low N2O emissions, <1% of the reduced nitrogen and a very stable and robust process towards variations in loads and process conditions. The second ANITA Mox plant, started up at Sundets WWTP in Vaxjo, Sweden, reached full capacity with more than 90% ammonia removal within 2 months from start-up. By applying a nitrogen loading strategy to the reactor that matches the capacity of the seeding carriers, more than 80% nitrogen removal could be obtained throughout the start-up period.
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| 3. |
- Stenis, Jan, 1960-, et al.
(författare)
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Flow analysis and economic modelling theory
- 2018
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Ingår i: 18th International Multidisciplinary Scientific GeoConference and Mining Ecology Management, SGEM 2018. - Sofia : International Multidisciplinary Scientific Geoconference. - 9786197408485 ; , s. 389-394
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Konferensbidrag (refereegranskat)abstract
- This study shows how material and immaterial flows can be analysed. The basis for the analysis is the equality principle and its mathematical expression the EUROPE model (the model for Efficient Use of Resources for Optimal Production Economy) which creates economic incentives to improve nature, advance the technological standard and increase profits. Particularly, the flows of cargo transportation, mega city supplies, long distance water transportation and various substance flows are described. The theoretical findings show viability for in general improving material and immaterial flows as well as the economy, the technological standard and the living conditions in the geographical regions in question. It is concluded that The EUROPE model based on the equality principle is in theory applicable on transportation policy issues, supplies to major cities, long distance water supply and important substance flows. In general, it is recommended to apply the EUROPE model when undertaking projects involving: transportation, mega city supply; transportation of water over long distances, and; flows of various substances.
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| 4. |
- Al-Najjar, Nasik, et al.
(författare)
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Cost-Effective Water Supply and Sanitation
- 2008
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Ingår i: 2nd-Environmental Conference-Water (KECW007), Dohuk Kurdistan Region in Iraq.
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Konferensbidrag (refereegranskat)abstract
- Water supply and sanitation have about the same goals all over the world. The needs for safe water supply and sanitation are obvious although not generally implemented. This depends often on the economical situation and bad management. Additional factors are effects of war actions and natural disasters as flooding of rivers and tsunamis. The strategies are, however, similar independent of the actual conditions. In this paper the strategies as developed in Sweden are described related to practical implementation of technology and management strategies. The experiences have shown on both mistakes and successful handling. Today, Sweden is involved in both adjusting policies according to European Union rules (as EU Water Framework Directive) and also in sharing experiences to facilitate international implementation of cost-effective methods.
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| 5. |
- Al-Najjar, Nasik
(författare)
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FRAMTIDA VATTENFÖRSÖRJNING FÖR VÄXJÖ KOMMUN : BEDÖMNING AV OLIKA ALTERNATIV
- 2008
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Ingår i: Vatten. - : Föreningen Vatten. - 0042-2886. ; 63:4, s. 299-311
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Water supply in Växjö municipality has since 1887 been based on surface water from Helga lake. A water treatment plant was built in 1957 and was extensively reconstructed in 1969 but there are still problems to accomplish with drinking water quality, mainly related to temperature, smell and taste, managanese and aluminum rest. Present water consumption periodically approached the water treatment plant maximum capacity. A performed risk analysis showed that catastrophic consequences for the water supply could occur due to an accident in a nearby traffic route or discharges from an industrial area.In 1997 Växjö municipality decided to perform a comprehensive investigation of different alternatives for future water supply. Seven alternatives were evaluated including remedial measures at the present water treatment plant. The chosen alternative was based on supply and conveying ground water from Berga esker at Ljungby municipality. Re-infiltration of ground water will be used to guarantee required water quality and quantity and will be implemented in autumn 2008 with a planned supply of 200 l per second delivered to about 70.000 persons in the municipalities of Växjö and Alvesta. The article describes the different alternatives, motives for the chosen alternative and the evaluation procedure.
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| 6. |
- Al-Najjar, Nasik, et al.
(författare)
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VA - SITUATIONEN I IRAK : PROBLEM OCH MÖJLIGHETER TILL MOTÅTGÄRDER
- 2004
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Ingår i: VATTEN: Tidskrift för vattenvård. - : Föreningen Vatten. - 0042-2886. ; 60:4, s. 269-274
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A summary is given on the water and wastewater situation in Iraq before the Gulf war 1991, the situation after the Gulf war and the recent effects of the conflict 2003. The access of safe water was halved in certain counties after March 2003 and half of the sewage works was out of function with a discharge of untreated wastewater to rivers and channels. The supply of electricity was less than 4 hours per day in January 2004 and caused discharges of untreated sewage on streets etc. Leakage from the water net was estimated to 60%. The wastewater system in 3 out of 5 schools was estimated to be out of function and epidemics have especially affected children and caused an increased mortality. Special issues as illegal openings of water pipes and security have worsened the situation. Swedish knowledge in water and wastewater handling may have an important role in rebuilding water and wastewater handling in Iraq and different possibilities are given.
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| 7. |
- Al-Najjar, Nasik, et al.
(författare)
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Water management and technology in Swedish municipalities. : Assessment of possibilities of exchange and transfer of experiences.
- 2009
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Ingår i: An International Perspective on Environmental and Water Resources Conference.
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Konferensbidrag (refereegranskat)abstract
- The water and wastewater infrastructure began to be developed in Sweden more than one hundred years ago. Much attention was given, in the beginning, to fire prevention and hygienic problems with water borne diseases. Somewhat later storm sewers (combined system) were constructed to remove storm water and wastewater and then successively more efficient wastewater treatment plants were developed. Today water and wastewater handling is seen as a multidisciplinary subject where also attention is given to possible effects of climate changes and possibilities for resources recovery.Implementation of advanced water and wastewater systems involves not only different technologies but also effective administration and legislation. The implementation may be on national (also involving EU directives), regional and local scale. As a case study, the local implementation will be illustrated for the municipality Växjö in South Sweden with about 80,000 inhabitants.
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| 8. |
- Bengtsson, Lars, et al.
(författare)
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Water balance for landfills of different age
- 1994
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Ingår i: Journal of Hydrology. - 0022-1694 .- 1879-2707. ; 158:3-4, s. 203-217
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Tidskriftsartikel (refereegranskat)abstract
- Water-related processes in landfills are discussed with emphasis on internal processes such as field capacity, moisture variation in time and space, and macropore flow. Runoff production and evaporation from landfills in Sweden of different age are investigated. It is clarified in what ways and for how long a closed municipal landfill differs from an ordinary land area from a hydrological point of view.
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| 9. |
- Dadvar, Atefeh, et al.
(författare)
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Water Use Behavior in a Multicultural Urban Area in Sweden
- 2021
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 13:15
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Tidskriftsartikel (refereegranskat)abstract
- The increasing world population and climate change are major concerns for the supply of water needs. Understanding user behavior facilitates the development of effective strategies of domestic water management. This research applied a questionnaire survey and data analysis methods to analyze the water consumption behavior of tenants in a multicultural urban area, dominated by immigrants of different ethnic origins, in the city of Växjö in Sweden. Results showed that the majority of the studied participants perceived themselves to be environmentally friendly. They reported to be engaged in water conservation activities quite often, but analysis showed that they did not have accurate perceptions of their water consumption. Positive attitudes towards water conservation and self-reported water conservation activities significantly but negatively influenced respondents’ actual water consumption, i.e., water consumption was higher. Subjective norms did not have a significant influence. The results also revealed that individual measurement and debit positively influenced, i.e., reduced, actual water consumption. Therefore, water management systems should include an individual measurement and debit system combined with a visualization system to enable tenants to monitor the quantity and cost of their water consumption.
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| 10. |
- Davidsson, Åsa, et al.
(författare)
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Effect of anaerobic digestion at 35, 55 and 60 °C ON pharmaceuticals and organic pollutants
- 2013
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Ingår i: Presented at the 1st International IWA Conference on Holistic Sludge Management, Västerås, Sweden, May 6-8, 2013. ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- The application of treated sewage sludge on farmland is a suggested method for recycling nutrients and reducing demand for commercial fertilizer. However sludge needs to be rendered safe from possible contaminants which can cause acute and long-term health and environmental problems. Residual pharmaceuticals and organic contaminants in sludge are mentioned as emerging threats since wastewater treatment plants are not designed to degrade these substances thus yielding an accumulation in sludge. The aim of this study was to evaluate the presence, and reduction, of pharmaceuticals and polycyclic aromatic hydrocarbons (PAHs) during anaerobic digestion at 35, 55 and 60ºC and during pasteurization at 70°C. The substrate used was mixed primary and secondary sludge from a 300 000 person-equivalents municipal wastewater treatment plant in southern Sweden. In general no reduction of pharmaceuticals could be observed at any temperature or minimum exposure time, except for the beta-blocker Irbesartan and the antibiotic Trimethoprim. The results from pharmaceuticals in mesophilic sludge agreed with results in recent Swedish studies. Also, no reduction of PAHs during digestion or pasteurization (70°C – 1 hour) was seen, but for single PAHs digestion could lead to reduction.
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