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  • 1.
    Andersson, Simon
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Callin, Veronika
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    SMÅSKALIG VATTENKRAFT OCH FLEXIBILITET I ELSYSTEMET: En kartläggning av förväntningarna på den småskaliga vattenkraftens potential att bidra med flexibilitet.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Fulltekst (pdf)
    fulltext
  • 2.
    Bouzidi, B.
    et al.
    Centre de Développement des Energies Renouvelables, CDER, BP 69 – Route de l’Observatoire, Bouzareah, Algiers, Algeria.
    Campana, Pietro Elia
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Optimization of photovoltaic water pumping systems for date palm irrigation in the Saharan regions of Algeria: increasing economic viability with multiple-crop irrigation2021Inngår i: Energy, Ecology and Environment, ISSN 2363-7692, Vol. 6, nr 4, s. 316-343Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Saharan regions of Algeria, which represent almost 90% of the total area of the country, have severe energy problems due to insufficient or lack of energy access. The sustainable development of those areas must aim at securing and increasing primary production, especially in the agricultural and pastoral sectors. The production itself depends on the supply of water available at great depths. However, the potential volumes of water pumped by photovoltaic water pumping systems are generally greater than the annual requirements for crop irrigation. In this study, we optimized the photovoltaic array, the storage tank and efficient use of the water produced by the pumping system for the irrigation of one hectare palm grove. This excess water produced was reduced by a judicious association by planting other crops (tomato, wheat and sweet pepper). The utilization rate has been improved from 56% to 86%, on the one hand. On the other hand, the impact of the yield and the prices on the economic viability was studied. The project is economically viable for a price per kg of date of 500.00 DA and a yield varying from 20 to 50 kg/tree, and the payback period varies from 3.34 to 1.22 years. The project is not economically viable for a price per kg of date of 100.00 DA/kg for a yield less than or equal to 30 kg/tree. A sensitivity analysis has shown that the photovoltaic water pumping system becomes more competitive than conventional diesel water pumping systems for diesel price beyond 53.98 DA/l (0.38 €). The results are very encouraging for the wide use of photovoltaic water pumping systems for multiple-crop irrigation in the Saharan regions. 

  • 3.
    Bratt, Ola
    Mälardalens universitet, Akademin för ekonomi, samhälle och teknik.
    DEVELOPING METHODS FOR WATER QUALITY MEASUREMENT: Using machine learning and remote sensing to predict absorbance with multispectral imaging2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Water resources play an important role in society and fulfill various functions such as providing drinking water, supporting industrial production and enhancing the overall landscape. Water bodies, such as rivers and lakes, are particularly important in this context. However, as societies and economies develop, the demand for water increases significantly. This also leads to the release of domestic, agricultural and industrial wastewater, which often exceeds the self-purification capacity of water bodies. Consequently, rivers and lakes are getting more and more polluted, endangering the safety of drinking water and causing ecological damage, affecting human health and biodiversity. 

    Water quality monitoring plays a crucial role in evaluating the state of water bodies. Traditional monitoring methods involve labor-intensive field sampling and expensive construction and maintenance of automatic stations. Although these methods provide accurate results, they are limited to specific sampling points and struggle to meet the demands of monitoring water quality across entire surfaces of rivers and lakes. This degree project aim at developing a method that can predict absorbance in water with the aim of remote sensing. Along with multispectral imaging and machine learning this work proves that this is possible. The result from multivariate analysis is an optimal model that can predict absorbance at 420 nm with RSQ of 0,996 and RMSE of 0,00081. 

    Fulltekst (pdf)
    fulltext
  • 4.
    Campana, Pietro Elia
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Mainardis, Matia
    Univ Udine, Dept Polytechn Engn & Architecture DPIA, Via Cotonificio 108, I-33100 Udine, Italy.
    Moretti, Alessandro
    Univ Udine, Dept Polytechn Engn & Architecture DPIA, Via Cotonificio 108, I-33100 Udine, Italy.
    Cottes, Mattia
    Univ Udine, Dept Polytechn Engn & Architecture DPIA, Via Cotonificio 108, I-33100 Udine, Italy.
    Corrigendum to “100% renewable wastewater treatment plants: Techno-economic assessment using a modelling and optimization approach” [Energy Convers. Manage. 239 (2021) 114214] (Energy Conversion and Management (2021) 239, (S0196890421003903), (10.1016/j.enconman.2021.114214))2021Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 244, artikkel-id 114531Artikkel i tidsskrift (Fagfellevurdert)
  • 5.
    Colin, Sonny
    et al.
    Mälardalens universitet, Akademin för ekonomi, samhälle och teknik.
    Erneland, Michael
    Mälardalens universitet, Akademin för ekonomi, samhälle och teknik.
    RAINWATER HARVESTING FROM ROOF TOPS IN URBAN AREAS: QUANTITY, QUALITY AND ENVIRONMENTAL BENEFIT: Case studies in Sweden and Colombia2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This study has looked at two separate locations, Malmö in Sweden, and Medellin in Colombia, and what the possibilities of rainwater harvesting are in those locations. The paper investigated data gathered by low-cost sensors in Malmö region, as well as sampling and measurements of rainwater collected in Malmö and Medellin, analysed by laboratories in both countries. Important data for the paper are quantity, quality, as well as environmental benefits and the economical perspective of rainwater harvesting. There are several steps that can be taken towards a more sustainable use of the Earth’s resources, and rainwater harvesting is included in the possibilities already at hand. But there is need for further development of monitoring and ways to qualify water for different purposes. It is possible to utilize rainwater for many things, and with that, ease the pressure on the local water supply infrastructure. This study has shown some important parts of that process, and that even low-cost sensors can help in gathering essential data for further evaluation of the usability of the rainwater. By collecting parts of the rainwater, flooding due to extensive downpour can be mitigated to some extent. Moreover, considering the low price of the sensors tested in this study, it is possible to use several low-cost sensors to determine the usability to some extent. Had the measurements rendered in values being too low compared to the laboratory results, the risk would have been greater. The consequence is that usable water could be regarded as not usable since the sensors returned an overall higher value compared to the laboratory results. Furthermore, the research found that the environmental benefit can be substantial. But there are more positive implications when gathering water for usage locally. For example, the water supply can become more distributed and with that, less prone to cause events such as water leaks, polluted water, and extreme events that have rendered an unserviceable infrastructure.

    Fulltekst (pdf)
    fulltext
  • 6.
    Diehl, Stefan
    et al.
    Lund University, Sweden.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Carlsson, Bengt
    Uppsala University, Sweden.
    Steady-State Analyses of Activated Sludge Processes with Plug-Flow Reactor2017Inngår i: Journal of Environmental Chemical Engineering, E-ISSN 2213-3437, Vol. 5, nr 1, s. 795-809Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Activated sludge processes (ASPs) consisting of a plug-flow reactor (PFR) and a settler are analyzed in steady-state operation using a reduced model consisting of one soluble substrate and one particulate biomass component modelling the dominating biological process. Monod biomass growth rate is assumed. Two settler models are studied. One is the commonly used ideal settler, or point settler, which is assumed to never be overloaded and to have unlimited flux capacity. The other recently published steady-state settler model includes hindered and compressive settling, and models a realistic limiting flux capacity. Generally, the steady-state concentration profiles within the PFR and the settler are governed by nonlinear ordinary differential equations. It is shown that the steady-state behaviour of the ASP can, however, be captured by equations without derivatives. New theoretical results are given, such as conditions by means of inequalities on input variables and parameters for a steady-state solution to exist. Another novel finding is that, if the incoming substrate concentration is increased from a low or moderate stationary value and the solids residence time is kept fixed, then this results in a lower effluent concentration in the new steady state. The steady-state equations are solved numerically for different operating conditions. For common parameter values, numerical solutions reveal that an ASP having a PFR, instead of a continuously stirred tank reactor, is far more efficient in reducing the effluent substrate concentration and this can be obtained for much lower recycle ratios, which reduces the pumping energy considerably.

  • 7.
    Färm, Carina
    Mälardalens högskola, Institutionen för samhällsteknik.
    Constructed Filters for Metal Reduction in Storm Water2002Inngår i: Vatten, ISSN 0042-2886, nr 3, s. 185-191Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Increased demand for storm water treatment has created development in filtration technologies for storm water. Manufacturers are using different filtration facilities and different filter materials. Therefore there is a need - from manufacturers, universities and government organisations - to put together current knowledge and to clarify important aspects concerning constructed filter systems. The first part of this paper reviews filtration facilities for storm water, filter substrates that have been tested for heavy metal reduction, and processes for contaminant transport through filter substrates. The second part of the paper presents an investigation of pine bark, used as a substrate in gully-pot filters for metal reduction in storm water.

  • 8.
    Färm, Carina
    Mälardalens högskola, Institutionen för samhällsteknik.
    Evaluation of the accumulation of sediment and heavy metals in a storm-water detention pond2002Inngår i: Water Science and Technology, ISSN 0273-1223, Vol. 45, nr 7, s. 105-112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accumulation of sediments and water quality were investigated in a wet storm-water detention pond in central Sweden. The drainage area surrounding the pond was covered by a section of highway and secondary roads. Sediment samples were collected from the pond and heavy-metal concentrations analysed subsequently in the laboratory. The depth of accumulated sediments was measured at several points around the pond. The investigation showed that during the 18 months that had passed since the pond was constructed, a 5-8 cm layer of sediments had accumulated near the inlet, and a 1.5 cm layer near the outlet of the pond. Storm water passing through the detention pond showed an average reduction rate of 26-84% for total metal content, 67% for total N, 78% for total P and 92% for COD.

  • 9.
    Färm, Carina
    Mälardalens högskola, Institutionen för samhällsteknik.
    Filtration of Storm Water for Metal Reduction using Natural Filter Substrates2002Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In order to immobilise pollutants in storm water—such as heavy metals that are either dissolved or bound to small particles—filter systems featuring various different filter substrates can be constructed to filtrate storm water. Two important parameters for the design and functioning of such a filter system include the load capacity and removal efficiency of the material used in the filter bed. These are essential considerations in the design of the filter itself. A sound knowledge of the operational and maintenance activities of these systems is also necessary for achieving reliable treatment systems. This paper describes an experiment where storm water from a section of highway and surrounding roads has been filtrated through experimental columns filled with specially selected natural filter materials—calcium silicate rock (opoka), zeolite and pine bark. Filtration was performed in a downward direction under unsaturated conditions. The efficiency of copper and zinc removal of a number of combinations of these filter substrates has been analysed. The average reduction of these metals in filtrated storm water was around 63–81%, depending on the combination of metal and filter substrate.

  • 10.
    Färm, Carina
    Mälardalens högskola, Institutionen för samhällsteknik.
    Metal Sorption to Natural Filter Substrates for Storm Water Treatment - Column Studies2002Inngår i: The Science of the Total Environment, ISSN 0048-9697, Vol. 298, nr 1-3, s. 17-24Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Storm water generated from road runoff contains pollutants such as metals that are either dissolved in storm water or bound to particulates. Using detention ponds for the treatment of storm water from road runoff, where particles can settle, can reduce the level of particulate-bound metals in the water, while small particles and dissolved matter pass through the detention pond. Some of these metals can be removed by filtrating water through specially constructed filter systems. This investigation is a laboratory study where different filter substrates were tested in order to evaluate their efficiency in reducing heavy metals from water. Metal solutions were filtered through columns filled with various substrates consisting of combinations of calcium silicate rock (opoka), zeolite and peat. The metal-removal efficiency was correlated to hydraulic load, and for the metal species the reduction efficiency decreased with increased hydraulic load. Mixtures of opoka and zeolite were found to be superior to the other filter-substrate combinations tested with regard to both hydraulic aspects and removal efficiency. Peat mixed with the calcium silicate rock was not successful due to clogging which stopped the experiment. A manufactured product made from the calcium silicate rock (burned opoka) was found to be less useful because of its calcium oxide (CaO) content. Among the tested filter substrates, mixtures of opoka and zeolite seemed to be the most useful compositions with respect to reduction-efficiency and clogging aspects. The removal capacity of metals varied from 0.6 to 1.8 kg m(-3) depending on the metal and the filter substrate. 

  • 11.
    Färm, Carina
    Mälardalens högskola, Institutionen för samhällsteknik.
    Removal of heavy metals in water by pine bark2003Inngår i: Vatten, ISSN 0042-2886, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [sv]

    Metals that are dissolved in storm water can be removed by filtrating water through specially constructed filter systems. Pine bark is an interesting material for this purpose, but it needs further investigations regarding its removal efficiency of metals. This paper presents a laboratory study where pine bark was tested to evaluate its efficiency in reducing heavy metals in water. Metal solutions were prepared and used in batch tests with pine bark. The metal removal efficiency was correlated to different metal concentrations in the solution and different contact times between the pine bark and the metal solution. The results showed that a high metal removal was achieved after a short contact time. The metal removal was low for low metal concentrations (0.1 mg/L) and higher for metal concentrations from 1 to 10 mg/L. The removal capacity was found to be 2.6 g Cu, 1.3 g Zn and 3.8 g Pb per kg pine bark. An investigation of the influence of chloride in the metal solution showed that the metal removal decreased by 15-23 %, depending on the metal, in the presence of chloride. Sorption isotherms of Zn, Cu and Pb on pine are also presented in the paper.

  • 12.
    Khokhotva, Oleksandr
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Waara, Sylvia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Urea treated pine bark -a low cost sorbent with improved metal sorption characteristics2009Inngår i: Ogolnopolska Konferencja naukowa inzynieria ekologiczna / [ed] Hanna Obarska Pempkowiak, Gdansk: Polish Academy of Science , 2009, s. 188-198Konferansepaper (Annet vitenskapelig)
  • 13.
    Nozhatzadeh, Ronja
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Kalhur, Rawand
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Förslag på dagvattenhantering: En fallstudie om Okvista bussdepå2021Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Purpose: This work aims to provide a new proposal for stormwater management in a bus depot in Okvista, Vallentuna in Stockholm. The proposal covers roof drainage as well as management and removal of heavy metals, oil and glycol in stormwater. The stormwater system is aimed to be designed based on the conditions of the facility and limit the risk of pollution spread. Method: A literature study on stormwater, various stormwater facilities and their calculation methods as well as occurring pollutants in bus depots was done for this study. Information regarding the case study, a bus depot in Okvista, has been collected through document analysis, a site visit and an interview. Calculations has also been done for the case study. Results: The proposal for roof drainage consist of two different solutions. The first solution is a green roof and rain garden. The second is plastic stormwater cassettes. The proposed stormwater treatment system consist of oil/water separator, bypass system, a well with the filter substrate granulated activated carbon and lastly a well where sampling of the water is possible. The proposal for glycol management is a raised curb and a ground slope at the heating ramp to separate the glycol from the rest of the stormwater on the site. The glycol runs down into a ditch where the degradation of glycol begins. From there, the glycol flows down to a pond equipped with and air pump. Conclusions: There are relatively few Swedish studies about this subject. Guidelines or regulations of how stormwater polluted with heavy metals and glycol should be managed, are not as clear and available as the management for oil polluted stormwater. The problem is not lack of solution but instead unclear regulations and guidelines for how and by whom these solutions should be applied. However, even though glycol contamination in bus depots is common, there is a lack of solutions for this problem. 

  • 14.
    Olsson, Jesper
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Forkman, T.
    Swedish University of Agricultural Sciences, Sweden.
    Gentili, F.G.
    Swedish University of Agricultural Sciences, Sweden.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Anaerobic co-digestion of sludge and microalgae grown inmunicipal wastewater: A feasibility study2018Inngår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 77, nr 3, s. 682-694Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study a natural mix of microalgae grown in wastewater of municipal character was co-digested with sewage sludge in mesophilic conditions, in both batch and semi-continuous modes. The semicontinuous experiment was divided into two periods with OLR 1 (Organic Loading Rate) of 2.4 kg VS m3 d-1 and HRT1 (Hydraulic Retention Time) of 15 days, and OLR2 of 3.5 kg VS m3 d-1 and HRT2 of 10 days respectively. Results showed stable conditions during both periods. The methane yield was reduced when adding microalgae (from 200 ± 25 NmL CH4 g VSin-1 , to 168±22 NmL CH4 g VSin-1). VS reduction was also decreased by 51%. This low digestability was confirmed in the anaerobic batch test. However, adding microalgae improved the dewaterability of the digested sludge. The high heavy metals content in the microalgae resulted in a high heavy metals content in the digestate, making it more difficult to reuse the digestate as fertilizer on arable land. The heavy metals are thought to originate from the flue gas used as a CO2 source during the microalgae cultivation. Therefore the implementation of CO2 mitigation via algal cultivation requires careful consideration regarding thesource of the CO2-rich gas.

  • 15.
    Olsson, Jesper
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Microalgae as biological treatment for municipal wastewater - Effects on the sludge handling in a treatment plant2018Inngår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, ISSN 0273-1223, Vol. 78, nr 3, s. 644-654Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A mix of microalgae and bacteria was cultivated on pre-sedimented municipal wastewater in a continuous operated microalgae-activated sludge process. The excess material from the process was co-digested with primary sludge in mesophilic and thermophilic conditions in semi-continuous mode (5 L digesters). Two reference digesters (5 L digesters) fed with waste-activated sludge (WAS) and primary sludge were operated in parallel. The methane yield was slightly reduced (≈10%) when the microalgal-bacterial substrate was used in place of the WAS in thermophilic conditions, but remained approximately similar in mesophilic conditions. The uptake of heavy metals was higher with the microalgal-bacterial substrate in comparison to the WAS, which resulted in higher levels of heavy metals in the digestates. The addition of microalgal-bacterial substrate enhanced the dewaterability in thermophilic conditions. Finally, excess heat can be recovered in both mesophilic and thermophilic conditions. 

  • 16.
    Samuelsson, Oscar
    et al.
    Uppsala University, Sweden.
    Björk, Anders
    IVL Swedish Environmental Research Institute, Sweden..
    Zambrano, Jesus
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Carlsson, Bengt
    Uppsala University, Sweden.
    Fault signatures and bias progression in dissolved oxygen sensors2018Inngår i: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 78, nr 5, s. 1034-1044Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biofilm fouling is known to impact the data quality of sensors, but little is known about the exact effects. We studied the effects of artificial and real biofilm fouling on dissolved oxygen (DO) sensors in full-scale water resource recovery facilities, and how this can automatically be detected. Biofilm fouling resulted in different drift direction and bias magnitudes for optical (OPT) and electrochemical (MEC) DO sensors. The OPT-sensor was more affected by biofilm fouling compared to the MEC sensor, especially during summer conditions. A bias of 1 mg/L was detected by analysing the impulse response (IR) of the automatic air cleaning system in the DO sensor. The IR is an effect of a temporal increase in DO concentration during the automatic air cleaning. The IRs received distinct pattern changes that were matched with faults including: biofilm fouling, disturbances in the air supply to the cleaning system, and damaged sensor membrane, which can be used for fault diagnosis. The results highlight the importance of a condition based sensor maintenance schedule in contrast to fixed cleaning intervals. Further, the results stress the importance of understanding and detecting bias due to biofilm fouling, in order to maintain a robust and resource efficient process control.

  • 17.
    Sylwan, Ida
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Runtti, Hanna
    Oulu University, Finland.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zambrano, Jesus
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Westholm, Lena Johansson
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    BIOCHAR ADSORPTION FOR SEPARATION OF HEAVY METALSIN MUNICIPAL WASTEWATER TREATMENT2018Konferansepaper (Annet vitenskapelig)
  • 18.
    Waara, Sylvia
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik. Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Waara, Karl-Otto
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Forsberg, Åke
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Fridolfsson, Magnus
    Performance of a constructed wetland system for treatment of landfill leachate.2008Inngår i: Waste 2008. Waste and Resource management-A shared responsibility, 2008, s. 655-667Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The performance of a constructed wetland for treatment of landfill leachate has been evaluated based upon data obtained during 4 years (2003-2006). It consists of a series of 10 ponds with a total capacity of 52.000 m3 covering 8 ha. Using univariate and multivariate statistics (PCA) the reduction pattern of a large number of chemical parameters including heavy metals has been investigated in 3 parts of the wetland with equal volume. Analyses show that many parameters are removed to the greatest extent in the first part of the system (e.g. many heavy metals, total suspended solids) or the second part of the system (N-NH4) while other parameters such as total nitrogen are more gradually reduced (10 ton/year removed).  Toxicity testing with 5 bioassays showed that toxicity was sometimes observed at the inlet but no toxicity was observed at the outlet for 4 of the test species. The data presented will be used for optimizing the treatment process as well as to improve the monitoring program.

  • 19.
    Westholm, Lena Johansson
    Mälardalens universitet, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Filter media for storm water treatment in sustainable cities: A review2023Inngår i: Frontiers in Chemical Engineering, ISSN 2673-2718, Vol. 5, artikkel-id 1149252Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Storm water treatment and management will be more important in the future due to climate changes, e.g., more frequent, and intense rain events that might cause flooding. To meet these challenges, low impact development (LID) technologies such as paved surfaces, green roofs and various bioretention systems have been suggested in urban areas. Various filter media, natural and engineered materials, have been used to amend the LID solutions in field experiments enhancing the removal of different contaminants present in storm water of different kinds. Researchers suggest locally available low-cost media having high capacity to remove pollutants. Other parameters to take into consideration when selecting filter media are clogging, hydraulic parameters. Climatic conditions in different regions, e.g., temperate, or cold climatic zones, do not seem to have a large impact on performance on LID solutions.

  • 20.
    Zambrano, Jesús
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Carlsson, Bengt
    Uppsala University, Sweden.
    Diehl, Stefan
    Lund University, Sweden.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    A Simplified Model of an Activated Sludge Process with a Plug-Flow Reactor2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The analysis of a simplified activated sludge process (ASP) with one main dissolved substrate and one main particulate biomass component has been conducted with respect to its steady-state. The ASP is formed by a plug flow reactor (PFR) and a settler with the recycling going to the reactor. The biomass growth rate is described by a Monod function. For this process, it is not possible to get an explicit expression for the effluent substrate concentration when the process is subject to a fixed sludge age. However,in the normal case when the influent substrate concentration is much greater than the effluent substrate concentration, then an explicit approximation for the effluent as a function of the influent and the process parameters is obtained. This work includes numerical examples considering two models for the settler. One model is the ideal settler, which assumes a complete thickening of the activated sludge through the underflow of the settler. The other model takes into account hindered settling and sludge compression. Numerical results show the effectiveness and the limitations of the proposed solution under these scenarios.

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