| 1. |
- Mattsson, Magnus, et al.
(författare)
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Effect of Particulate Air Cleaners on the Content of airborne Dust and Cat Allergen in Classrooms
- 2004
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Ingår i: Roomvent 2004. - 9729797323
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Konferensbidrag (refereegranskat)abstract
- Electrostatic air cleaners (precipitators) were tested in four classrooms during ordinary lessons for four weeks. Airborne dust in the classrooms was collected on filters using two different kinds of samplers: IOM-sampler and a new kind of ionizing sampler. The amount of collected dust was evaluated by visual inspection (“filter blackening”) and the content of cat allergen was measured using an amplified ELISA assay. It was found that the filter blackening was 64% lower when the air cleaners were active than when they where inactive (p<0.001). This suggests that the air cleaners were effective in reducing the content of airborne particulate matter. The reduction in cat allergen appeared however to be less substantial. The variance of the allergen data was unexpectedly large, presumably due to relatively few allergen-carrying particles in the sampled air. It is believed that larger sampling volumes are needed to get more reliable data of airborne cat allergen in spaces where the allergen is emitted indirectly.
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| 2. |
- Mattsson, Magnus, et al.
(författare)
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Mixing and displacement ventilation compared in classrooms; distribution of particles, cat allergen and CO2
- 2003
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Ingår i: Proceedings from Healthy Buildings 2003. ; , s. 458-464
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Konferensbidrag (refereegranskat)abstract
- Mixing ventilation and displacement ventilation were compared in an intervention study in classrooms. Particles, cat allergen and CO2, were measured in classroom air at different levels above the floor, during regular lessons. With mixing ventilation, the particle concentration tended to decrease with height, with a stronger gradient occurring for larger particles. With displacement ventilation, the particle concentration increased with height, except for particles >25 µm. The displacement system thus tended to have a slight upward displacement effect on most of the particles. Significant correlations were found between concentrations of cat allergen and particles in the size fraction 1–10 µm. The particle and cat allergen concentration at breathing height did not, however, differ significantly between the two ventilation systems. CO2 was about 10% lower with displacement ventilation. A fairly high level of physical activity of the pupils is believed to have had significant dispersing effect on the airborne contaminants.
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| 3. |
- Mattsson, Magnus, 1964-, et al.
(författare)
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Ventilation filter efficiency for birch pollen allergens : experimental data from one pollen season
- 2011
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Ingår i: Proceedings from Roomvent 2011. - Trondheim : Tapir Akademisk Forlag. - 9788251928120
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Konferensbidrag (refereegranskat)abstract
- In an experimental study, ventilation filters of high quality (F7 & F9) were tested regarding their efficiency in collecting birch pollen allergens in outdoor air. The birch pollen grain concentration in outdoor air was measured at the same time as pollen allergen and particle number concentrations were measured before and after the tested ventilation filters, thus enabling collection efficiency calculations. Simultaneously, the size distribution of birch pollen allergens was measured in outdoor air using a cascade impactor. The study confirms previous indications that pollen allergens may occur in outdoor air in particles much smaller than pollen grains, and can penetrate ventilation filters to a larger extent than might be expected. This entails that although the high quality filters collect most of outdoor air pollen allergens, a significant exposure dose to these allergens can occur in the indoor environment, especially when considering the fact most people stay much more indoors than outdoors. The study also confirms previous similar indications attained with grass pollen allergens, in that the allergenic particles tend to penetrate ventilation filters to a greater extent than other airborne particles.
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| 4. |
- Carlos-Pinedo, Sandra, et al.
(författare)
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Study of the digestion process at a full-scale solid-state biogas plant by using ORWARE : Model modification and implementation
- 2020
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 107, s. 133-142
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Tidskriftsartikel (refereegranskat)abstract
- The configuration of the reactor influences the digestion process and thus the product yields; other factors such as the rate of biogas production or biogas loss also affect the process specifically with high solid configuration. With these in mind, the ORganic WAste REsearch (ORWARE) anaerobic digestion sub-model was modified to be able to study solid-state anaerobic digestion (SS-AD) (using plug-flow reactor). The simulation results from the updated model agreed with the operational data with respect to methane yield, digestate yield and energy turnover. The model was found to be sensitive to changes in feedstock composition but to a lesser extent to changes in process temperature and retention time. By applying the model on several cases of liquid anaerobic digestion (L-AD), it was noticed that L-AD at mesophilic condition with 25 retention days seemed to be superior to other cases of L-AD with regard to energy turnover. However, even if similar methane production were observed for L-AD and SS-AD, the model suggested higher energy turnover for the case of SS-AD at thermophilic condition, being 10% more in average in comparison with cases of L-AD.
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| 5. |
- Ljunggren Söderman, Maria, 1967, et al.
(författare)
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Integrated Economic and Environmental Assessment of Waste Policy Instruments
- 2016
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- The need for new policy instruments supporting the on-going transition from end-of-pipe waste treatment to resource management has been recognized in European policy. Instruments need to be carefully assessed before implementation to promote the desired changes and avoid problem shifting. Mathematical models may assist policy makers in such assessments. This paper presents a set of soft-linked models for assessing the economic and environmental impacts of policy instruments for both the prevention and management of waste and discusses its strengths and limitations. Consisting of (1) a macro-economic model, (2) a systems engineering model for waste management and (3) a life cycle assessment model for waste management, the set is primarily suited to assessing market-based instruments and environmental regulations. Considerable resources were needed for developing and using the set, and there are clear limits as to what can be addressed. However, if only one of the models had been used, neither the range of instruments nor the scope of impacts would have been possible to cover. Furthermore, soft-linked models allow many disciplines to contribute within one harmonized framework. Such integrated assessments may become increasingly useful for continuing the implementation of policy for sustainable governance of society's material resources.
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| 6. |
- Rani Singhania, Reeta, et al.
(författare)
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Consolidated Bioprocessing of Lignocellulosic Biomass: Technological Advances and Challenges
- 2022
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 354
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Tidskriftsartikel (refereegranskat)abstract
- Consolidated bioprocessing (CBP) is characterized by a single-step production of value-added compounds directly from biomass in a single vessel. This strategy has the capacity to revolutionize the whole biorefinery concept as it can significantly reduce the infrastructure input and use of chemicals for various processing steps which can make it economically and environmentally benign. Although the proof of concept has been firmly established in the past, commercialization has been limited due to the low conversion efficiency of the technology. Either a native single microbe, genetically modified microbe or a consortium can be employed. The major challenge in developing a cost-effective and feasible CBP process is the recognition of bifunctional catalysts combining the capability to use the substrates and transform them into value-added products with high efficiency. This article presents an in-depth analysis of the current developments in CBP around the globe and the possibilities of advancements in the future.
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| 7. |
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| 8. |
- Eriksson, Ola, et al.
(författare)
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Enhancement of biogas production from food waste and sewage sludge : environmental and economic life cycle performance
- 2016
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 175, s. 33-39
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Tidskriftsartikel (refereegranskat)abstract
- Management of municipal solid waste is an efficient method to increase resource efficiency, as well as to replace fossil fuels with renewable energy sources due to that (1) waste to a large extent is renewable as it consists of food waste, paper, wood etc. and (2) when energy and materials are recovered from waste treatment, fossil fuels can be substituted. In this paper results from a comprehensive system study of future biological treatment of readily degradable waste in two Swedish regions are presented. Different collection and separation systems for food waste in households have been applied as well as technical improvements of the biogas process as to reduce environmental impact. The results show that central sorting of a mixed fraction into recyclables, combustibles, biowaste and inert is a competitive option compared to source separation. Use of pellets is beneficial compared to direct spreading as fertiliser. Fuel pellets seem to be the most favourable option, which to a large extent depends on the circumstances in the energy system. Separation and utilisation of nitrogen in the wet part of the digestion residue is made possible with a number of technologies which decreases environmental impact drastically, however to a substantial cost in some cases.
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| 9. |
- Eriksson, Ola, et al.
(författare)
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Hästkrafter och hästnäring – hållbara systemlösningar för biogas och biogödsel : Explorativ systemanalys med datormodellen ORWARE
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Antalet hästar i Sverige ökar och enligt beräknad statistik från Jordbruksverket finns det uppskattningsvis 360 000 hästar i landet. Dessa hästar återfinns i olika typer av verksamheter (jordbruk, turridning, trav och galopp med mera) och ger upphov till stora mängder hästgödsel. Hästgödsel består av fekalier, urin och strömaterial där olika strömaterial används olika mycket. Hanteringen av hästgödseln medför miljöproblem då miljöstörande ämnen avges vid nedbrytning av det organiska materialet, samtidigt som växtnäringsämnen inte återförs till kretsloppet. Intresset för att kunna röta hästgödseln och tillverka biogas har ökat i och med ett ökat intresse för biogas som förnybart drivmedel.Denna studie har haft som mål att belysa miljöpåverkan från olika sätt att hantera hästgödsel i ett systemperspektiv. Särskild uppmärksamhet har riktats mot inblandningen av olika typer av strömedel och hur det påverkar effektiviteten i olika behandlingsprocesser. Behandlingsmetoderna som undersökts ärOkontrollerad komposteringKontrollerad komposteringStorskalig förbränning i ett avfallskraftvärmeverkTorkning och småskalig förbränningTorrötningVåtrötning med och utan termisk förbehandlingTill följd av betydande dataosäkerhet i undersökningen är resultaten endast indikativa men de pekar ändå på storskalig förbränning som en miljömässigt bra metod. Undantag utgör bidrag till klimatpåverkan där rötning i olika former är att föredra. Utifrån undersökningen av olika strömaterial framstår pappersströ som ett intressant alternativ att gå vidare med.Den övergripande slutsatsen är att mer forskning behövs för att säkerställa kvaliteten i kommande undersökningar, det vill säga en samlad forskningsinsats från hästhållning till avfallshantering.
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| 10. |
- Eriksson, Ola, et al.
(författare)
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Life cycle assessment of horse manure treatment
- 2016
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- Horse manure consists of feces, urine, and varying amounts of various bedding materials. The management of horse manure causes environmental problems when emissions occur during the decomposition of organic material, in addition to nutrients not being recycled. The interest in horse manure undergoing anaerobic digestion and thereby producing biogas has increased with an increasing interest in biogas as a renewable fuel. This study aims to highlight the environmental impact of different treatment options for horse manure from a system perspective. The treatment methods investigated are: (1) unmanaged composting; (2) managed composting; (3) large-scale incineration in a waste-fired combined heat and power (CHP) plant; (4) drying and small-scale combustion; and (5) liquid anaerobic digestion with thermal pre-treatment. Following significant data uncertainty in the survey, the results are only indicative. No clear conclusions can be drawn regarding any preference in treatment methods, with the exception of their climate impact, for which anaerobic digestion is preferred. The overall conclusion is that more research is needed to ensure the quality of future surveys, thus an overall research effort from horse management to waste management.
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