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  • 1.
    Andersson, Ramon
    Halmstad University.
    Hållbart jordbruk inom vattenskyddsområde: En studie om Sverige, Danmark, Frankrike och Tyskland2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To guarantee protection of our drinking water, water catchment protections are established. These are divided into three different zones and in the first zone it is most likely that an activity, such as agriculture, will contaminate the water resource. Hence the activities are strongly regulated or banned. The EU communion is working towards a sustained water quality through several directives; Nitrate Directive, Waterframwork directives and Sustainable use of pesticide directive. The main purpose is to regulate the diffuse pollution from agriculture.This thesis is about how Denmark, Germany and France are working towards a sustainable agriculture within water protection areas. Sweden is also discussed but mainly about two different methods applied in Linköpings and Ljungbys municipalties.How the different countries work is mainly the same due to the directives. However, there are some interesting water management methods to observe such as voluntary agreements between water companies and farmers. Moreover, the sustainability perspective is approached in a larger scale where you and I as consumers also contribute via consumer-pays-principle. Therefore, we are, by our demand for water, the problem but also the solution and together we can contribute with good social, economic and ecological conditions for ourselves and the farmer.

  • 2.
    Bohman, Mattias
    et al.
    Grontmij AB.
    Berglund Odhner, Peter
    Grontmij AB.
    Schabbauer, Anna
    Grontmij AB.
    Karlsson, Niklas
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Mattsson, Marie
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Rundstedt, Johan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Biogas i Halland: Förbehandling av substrat och simulering av biogasflöden2011Report (Other academic)
    Abstract [sv]

    Bioenergicentrum i Halland (BEH) är ett projekt som ligger inom ramen för EU:s strukturfondsprogram. Projektet genomförs i Region Hallands regi som är regionens välfärds- och utvecklingsorganisation. Arbetet som bedrivs inom BEH syftar speciellt till att driva utvecklingen mot en ökad produktion och användning av bioenergi till biogas och i förlängningen fordonsgas. Genom att satsa på att skapa förutsättningar för innovation, kunskapsutveckling och samverkan främjas tillväxt och hållbar utveckling.

    Vid naturbruksgymnasiet i Plönninge utanför Halmstad finns idag en biogasanläggning som beskickas med bl.a. nötgödsel och matavfall. Dessutom finns en mindre pilotanläggning som är tänkt att fungera som en del av test- och verifieringsanläggning som BEH vill bygga upp i Plönninge. Som ett led i att utveckla dessa anläggningar och kunna erbjuda möjligheten till kunskapsinsamling genomfördes projektet som beskrivs i denna rapport. Uppdraget var att genomföra försöksrötningar på labb, använda resultaten för att skapa en modell som sedan kan nyttjas som ett verktyg i det inledande arbetet med att investera i en biogasanläggning som beskickas med lantbruksbaserade substrat. Högskolan i Halmstad (HH) genomförde försöksrötningarna och Grontmij (GM) använde sedan resultaten för att skapa en modell där bl.a. substrat, förbehandlingsteknik och driftkostnader finns med.

    Sammanfattningsvis kan sägas att majs som substrat fungerar bäst med de valda förbehandlingsmetoderna; kemisk behandling, termisk behandling och ultraljudsbehandling. Alla förbehandlingsmetoder med majs som substrat visade på ett positivt resultat, d.v.s. det ökade gasutbytet och dess värde (kr/kWh) översteg kostnaderna för de olika förbehandlingarna. Vad som måste beaktas är att produktionskostnaderna överlag är höga, med och utan förbehandling.

    Modellen har konstruerats på ett sådant sätt att den ska vara användarvänlig och med möjlighet att enkelt lägga till ytterligare substrat och förbehandlingsmetoder. Upprepningar av de försöksrötningar som genomförts kommer att öka tillförlitligheten hos modellen. Den fungerar som ett verktyg i att beräkna investeringsmarginalen för förbehandlingsutrustningen baserat på det valda substratet. På detta vis kan intressenter få en första indikation på om det är ekonomiskt rimligt att gå vidare med det tänkta substratet, den valda förbehandlingsmetoden, de planerade mängderna substrat etc.

    En investeringskalkyl har tagits fram för en gårdsanläggning som hanterar 5 000 ton substrat eller gödsel årligen. Det motsvarar 2-3 stycken medelstora mjölkgårdar. Kalkylen är översiktlig och syftar till att ge en första indikation på kostnader för de stora komponenterna såsom substratlager, rötkammare och rötrestlager. Kringarbeten såsom utredningar, markarbeten och geoundersökningar är inte med i kalkylen då dessa omkostnader till stor del avgörs av lokalisering och de förutsättningar som finns på platsen redan från start. Generellt kan dock sägas att den absolut billigaste och enklaste gårdsbaserade biogasanläggningen innebär en investering på 2,7-4 MSEK för flytgödsel från 100-300 mjölkkor.

    För BEH är det viktigt att skapa en plattform där intressenter kan komma för att genomföra försöksrötningar, byta erfarenheter och samla kunskap. För att uppnå detta är det nödvändigt att kunna erbjuda kunden kompletta och kompetenta lösningar på en och samma plats. Detta innebär ett erbjudande som innefattar försöksrötningar på labb-, pilot och fullskala. Ett förslag på konstruktion av pilotanläggning med övergripande principskiss ingår i denna rapport och fungerar som ett inledande arbete i projekteringen av en större pilotanläggning. Nödvändiga driftanalyser av rötrest ska kunna göras på plats i Plönninge på laboratoriet; analyser såsom enskilda organiska syror ska kunna skickas till lämpligt laboratorium. Personal ska kunna tillhandahållas för att driva och optimera rötningen enligt kundens syften och önskemål. På detta vis fungerar Region Halland som en länk mellan teori ochpraktik, mellan liten och stor skala och mellan aktörer från olika discipliner och geografiska områden.

  • 3.
    Cansu Ertem, Funda
    et al.
    Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany.
    Wang, Liqian
    Shanghai Institute of Applied Physics, Shanghai, China.
    Mattsson, Marie
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Analyzing the impacts of inoculums to substrate ratio and pretreatment methods on the anaerobic biogas production from sugar beets2016In: ETIKUM 2016: Proceedings, Novi Sad: Faculty of technical sciences department of production engineering , 2016, p. 113-116Conference paper (Refereed)
    Abstract [en]

    This study evaluates the impacts of three different pretreatment methods on the biogas production from sugar beet, when it is anaerobically digested with a variety of inoculum mixing ratios. In this context, this research focuses on the influences of different pretreatment methods and inoculum on the digestibility on the digestibility. Sugar beet was anaerobically digested at 37°C. Actively digested cow manure slurry, vegetable and fruit residues mix was used as inoculum. The series of laboratory experiments using 32 digesters (each 1 L) were performed in batch operation mode. The results prove that inoculum and pretreatments could either enhance the biogas potential or totally inhibit the digestion. Key words: sugar beet, inoculum, pretreatment methods, biogas production.

  • 4.
    Huerta Buitrago, Belinda
    et al.
    School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Ferrer Munoz, Patricia
    School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Ribé, Veronica
    School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Larsson, Maria
    Man-Technology-Environment Research Center, School of Science and Technology, Örebro University, Örebro, Sweden.
    Engwall, Magnus
    Man-Technology-Environment Research Center, School of Science and Technology, Örebro University, Örebro, Sweden.
    Wojciechowska, Eva
    Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Gdańsk, Poland .
    Waara, Sylvia
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS). School of Sustainable Development of Society and Technology, Mälardalen University, Västerås, Sweden.
    Hazard assessment of sediments from a wetland system for treatment of landfill leachate using bioassays2013In: Ecotoxicology and Environmental Safety, ISSN 0147-6513, E-ISSN 1090-2414, Vol. 97, p. 255-262Article in journal (Refereed)
    Abstract [en]

    Four bioassays were used in this study for the hazard assessment of sediments from sediment traps and several ponds in a treatment wetland for landfill leachate at Atleverket, Sweden. In the 6-day solid phase microbiotest with the sediment-dwelling crustacean Heterocypris incongruens both acute and chronic effects were observed with a gradual decrease and loss of toxicity with treatment in the wetland system. Some samples showed a low toxicity in porewater and only one sample was weakly toxic in the whole sediment test when assessed with Aliivibrio fischeri (Vibro fischeri). No genotoxicity was detected in the umu test. The toxicity response in the H4IIE- luc test evaluating the presence of dioxin-like compounds was considerably higher in the samples from the sediment traps. The hazard of the sediment therefore appears to be highest in the sediment traps and pond 1 with the methods employed. The result indicates that the wetland system has a design supporting the concentration and sequestration of toxic substances in the first part of the wetland. Based upon the results we suggest that hazard assessment of sediments from other treatment wetlands for landfill leachate should be conducted. (c) 2013 Elsevier Inc. All rights reserved.

  • 5.
    Jaggwe, Assad
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Effects of Environmental Variables on Four Aquatic Insect Taxa among Smaller Water Bodies of Different Ages on Farmland; A Pilot Study2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    High anthropogenic modification like infrastructural development, drainage, eutrophication, dumping garbage, is a threat to biodiversity of smaller water bodies in agricultural landscapes. However, smaller water bodies have historically been constructed for drainage, waste treatment and other purposes. Further, new small water bodies are now being constructed in agricultural areas in Sweden, mainly to remove nutrients and to improve landscape biodiversity. This creates two different age classes (old and new) of smaller water body habitats. I sampled aquatic insects in 27 smaller water bodies of varying types and ages in Halmstad region and related insect biodiversity, species richness, composition structure to environmental variables. I partitioned the region into two locations (Northern and Southern) for easy data comparison and due to difference in topography. The data was analysed using a Canonical Correspondence (CCA) and regression analysis. The CCA results show a difference in the species composition between old and new sites. The most important variables in explaining species assemblage structure was age of the aquatic water bodies. The species richness decreased with increase in nutrient concentration (total phosphorus) according to regression analysis. Species composition and diversity were related to Vegetation and tree cover in and around the water body. The results of my study shows that the older the water bodies the better for specific species like Aeshna cyanea and the new water bodies tolerate more specimens. My results suggest that, as there is need to facilitate plant growing, protecting vegetation and trees to better mimic natural conditions of water bodies, creating new water bodies while protecting aged water bodies is important for conservation of biodiversity.

  • 6.
    Kalén, Jonas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Åkerlund, Nathan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Gårdsbaserad biogas på Nya Skottorp: utvärdering och optimering av anläggningen och uppgradering av biogasen2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Biogas is an expanding sector within the broad field of agriculture and animal production. Small-scale biogas offers local combined power and heating production and the substrate is transformed into high-quality biological fertilizer. This bachelor thesis focuses on a pig farm in south-western Sweden, where biogas is produced from pig manure, evaluates and suggests ways of optimizing the process and investigates whether investing in an upgrading plant would be a feasible and more cost-efficient option. The results show that the biogas plant is working well, although the production differs from the original plans. This shows in turn that planning and examining the basic conditions before making the investment is of great importance, as well as monitoring and keeping detailed statistics of the running process. Logistical factors make optimizing the process through additional substrates difficult. The thesis shows that investing in a Biosling upgrading plant would be a profitable option, supposing that the upgraded gas is sold via the natural gas infrastructure. Furthermore, many farmers are interested in producing their own fuel for tractors and other machines, which offers more future alternatives for the upgraded biogas. However, biogas producers in Sweden today are not offered any particular subsidies, which makes it especially hard for small-scale producers.

  • 7.
    Karlsson, Niclas
    Halmstad University, School of Information Technology.
    Övervakningssystem av Grisstall med detektion av blod2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work in this project demonstrates how a system for monitoring pigs could be handled andtests a camera for this kind of system. Automatic detection of blood will help in a keeper’s dutiesand give him or her a different view of the box. Management of multiple camera modulesis done automatically via a server application that can manage a different number of cameramodules in the system. More camera modules can be included simply by modifying the serverprogram.Display of each box is made web based causing environmental and economic sustainabilitywhen the keeper can handle the daily monitoring by the home instead of on the farms especiallyon weekends. It is also possible to keep check during the night when the night visionapplication on the camera is available and retroactive supervision since the images are savedfor twenty four hours.When young pigs are introduced into the living area they need more food than normally resultingin increased feed supply. By monitoring via a web based application the keeper cansupply an increase or decrease of food if necessary. By continuing to work on this project implementationof more features and more user-friendly details can be included. Detection ofblood can also be extended to the estimate of food levels and manage food delivery via the web application.

  • 8.
    Karlsson, Tommy
    Halmstad University, School of Business and Engineering (SET).
    Biogasrötning av socker- och foderbetor: Jämförelse av färska, stuklagrade samt ensilerade betor i laboratorieskala2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fossil fuels are affecting our climate negatively and there is a limited amount of them in the world, which leads to the importance of finding alternative fuels. One alternative is biogas, which is produced though a digestion process of different organic materials in a biogasreactor. Organic substrate that comes from farms has the biggest potential to increase the production of biogas in Sweden. Primarily crops from farms, but also waste products like manure are of great importance.

    Today there is a calculated theoretical potential for biogasproduction of 14TWh per year, which is around ten times larger than Sweden’s production today. This potential depends on how much arable land that is used to produce crops for biogas though, and can be much larger. The biggest contributor to increase the biogasproduction is crops from farms and manure3. The reason for this is because sugar- and fodderbeets contain the highest amount of energy per hectare arable land for crops, and therefore it is interesting to study how to optimize the use of this energy.

    Usually the beets have to be stored after the harvest since the most of the beets cannot be used directly, and a consistent feed to the biogas reactors is favorable. The most common way to store the beets today is in covered storage or silage. The beets are usually in need of being co-digested together with another substrate since the amount of nitrogen that the beets contain are relatively low, and therefore the beets may be in need of co-digest with a substrate that contains a higher amount of nitrogen. For example are manure or slaughterwaste substrates containing high amounts of nitrogen, and therefore are co-digestion between beets and these kinds of substrates improving the ratio between carbon and nitrogen, which improves the digestion process. This is the reason why the beets were co-digested with manure from cattle during this study.

    The goal with this study were to compare newly harvested sugar- and fodderbeets potential for biogasproduction, with the production from beets that were placed in covered storage respectively silage. Another goal was to decide which type of beet, storage method and pre-treatment method that are the most optimal for co-digestion with manure from cattle.

    The tests showed that when newly harvested sugar- and fodderbeets were added the part size were a more important factor then when the beets had been stored or ensilaged. For newly harvested sugarbeets the biggest part size gave the highest production, while the newly harvested fodderbeets of the same size did not have time to digest properly, which resulted in that their production were the lowest. When the haulm from sugarbeets were added together with sugarbeets and co-digested with manure from cattle the results were more like the results from the fodderbeets.

    During the tests ensilaged beets had a higher production than the newly harvested and the beets that were stored covered. Even though the results from the ensilaged beets were modified since losses occurred from the ensilation process. Comparison between the groups showed no bigger differences in production for the sugarbeets, while for fodderbeets the second largest part size had a higher production than the others with fodderbeets. With ensilaged sugarbeets together with the haulm there was shown that the group with the second most amount of haulm gave a higher production than the rest of the groups that were co-digested with haulm.

    The tests can be concluded by that newly harvested and the sugarbeets that were stored covered are more suitable to be co-digested together with manure from cattle than fodderbeets when looking at these percentage admixtures and preconditions. When the beets have been ensilaged is it more favorably to use fodderbeets then sugarbeets together with manure from cattle. The part size was shown to have no bigger significance. To sum up ensilaged beets over all seem to be more favorably to co-digest with cattle manure than newly harvested or beets that were in covered storage. The production per gram VS were significantly higher although correction calculations.

  • 9.
    Landgren, Emilia
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Wallman, Sabina
    Halmstad University, School of Business and Engineering (SET).
    Hästavmaskningsmedels påverkan på miljö och välfärd2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Healthy, natural pastures is very valuable for biodiversity in the form of both plants and animals. An efficient use of pastures helps to preserve biodiversity, but grazing animals needs to be de-wormed to keep them healthy and to prevent harmful parasites spread on the pasture. The awareness about the environmental impact of the frequent use of deworming agents is low among the public. Some people are unaware that the absorption in horses of anthelmintics is incomplete, which make the circumstances about enviromental effect important to investigate further. The scientific evidence in this area is limited and more studies and trials are needed to deepen the knowledge about the effects of anthelmintics in the environment. Our report includes a compilation of studies conducted on anthelmintics and equine parasites, as well as an experiment which was conducted at the University of Halmstad biogaslaboratory April 2014. Anthelmintics have been shown to have negative impact on the manure ecosystem and especially against manure living fauna. Deworming routines has changed over the years as the equine industry has developed. Nevertheless, there’s still a lack of concrete approach to deworming.

  • 10.
    Lerin, Tommy
    Halmstad University, School of Business and Engineering (SET).
    Förutsättningar och Avsättningar för Biogas för Gröna Vessigebro: Version 1.02014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The community Vessigebro, in Falkenberg and its surrounding areas housing one percent of all dairy cattle and two percent of all pigs in Sweden. This means that there is a large amount of manure as a basis for producing biogas in the area. A number of farmers have therefore formed a cooperative named Vessigebro biogas and started the project Green Vessigebro, with the goal of creating the conditions for a more profitable and more sustainable agriculture production.

    The study deals with the conditions and sale opportunities of the feasibility study Green Vessigebro. The study has looked at the work that was previously carried out for the biogas that could be produced on the farms in Vessigebro, The main pipeline for natural gas on the Swedish west coast and its operators, the Swedish Competition Act , Electricity Act , Natural Gas Act, the District Heating Act , Sustainability Act , previously proposed measures, municipality interest in biogas from Vessigebro , possible collaborations, possible sale opportunities and perform calculations with data from the municipality Ljungby for a suggested transportation of biogas between Vessigebro and Ljungby.

    The study shows that there are several interesting sale opportunities for biogas from Vessigebro. The production and use of biogas in Sweden is increasing and the trend seems set to continue. Six gas retailers can buy gas, which EON is the most established around Vessigebro with a distribution network. EON: s distribution network runs only a few kilometers from the planned upgrading plant , in Vessigebro. An already built upgrading facility is one mil from Vessigebro. Swedegas is the only main pipeline network owner with storing and balancing responsibility on the main line that is closer than EON distribution network. A number of suppliers and industries have shown interest in purchasing the biogas and the interest from potential buyers are likely to increase when the biogas production starts. A collaboration with, for example, "Arena Bioenergy Halland" increases business intelligence and can provide an increased influence with policy proposals. The use of gas and the interest is too low for the moment for tractors, boats, trains, buses and taxis to be a possible outlet specifically for Vessigebro biogas.

    The conditions make it interesting for Vessigebro biogas to look at five different options for sale opportunities of the biogas. Three options are based on a pipeline to either the pipeline, owned by Swedegas or EON distribution line alternatively a pipeline to EON upgrading facility. One possibility is to replace vehicles that run on fossil fuels with gas-powered vehicles providing a local use and purpose and the aims of the project Green Vessigebro. The calculations made by the study with different conditions shows that a very interesting and possible sale opportunity is a transportation of biogas between Vessigebro and Ljungby.

    The conclusion from the study shows that conditions and sale opportunities are good for the planned biogas production of Green Vessigebro to become reality.

  • 11.
    Lindeberg, Jasmine
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science.
    Brandt, Victor
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science.
    An evaluation of the effects from livestock farming using water conditions and Odonata species:: Could Odonata act as indicators of eutrophication?2016Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 12.
    Lundquist, Kristin
    Halmstad University, School of Business, Engineering and Science.
    Vildsvinsbök i skogsmark – en studie i tre områden i Mellansverige2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In April-July in 2010, three forest dominated areas in central Sweden were studied to investigate wild boar rooting habits. The results showed that rooting mainly occurred in pine-and spruce dominated habitats where tree-ages varied between 45-90 years old and with ground surface vegetation consisting of shrubs (blueberry/lingonberry), mosses and grass. In two of the three study areas the size of rooted areas was not affected by factors such as tree species composition, forest age or vegetation ground cover, but correlations between these factors were found in one of the areas. The size of rooted areas was not affected by the population density or the time with wild boar present in the area.

  • 13.
    Mishra, Navin
    Halmstad University.
    Analysis of fault ride through disturbances in wind energy2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 14.
    Sandström, Sofia
    Halmstad University, School of Business and Engineering (SET).
    Stereotypa beteenden hos hästar: Kartläggning av ridanläggningar samt pilotstudie2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 15.
    Sundström, Michaela
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Tillman, Therese
    Halmstad University, School of Business and Engineering (SET).
    DIG - Djurskyddsindikatorer Gris: Ett system för att mäta välfärd i grisbesättningar2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 16.
    Waara, Sylvia
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Bandaruk, Tatsiana
    Halmstad University, School of Business and Engineering (SET).
    Metal and Metalloid Sequestration in a Constructed Wetland System for Treatment of Landfill Leachate During 2003–20122014Conference paper (Other academic)
    Abstract [en]

    The treatment of landfill leachate in constructed wetland systems is a common practice in Europe. However, very few studies were made to evaluate their performance over a long period of time. A free surface constructed wetland system consisting of sediment traps followed by 10 ponds connected with overflows was built at Atleverket near Örebro, Sweden in 2001. It receives pre-treated leachate from the municipal landfill. As part of the wetland monitoring programme a large data set on the surface concentrations of 15 metals and 2 metalloids has been collected from different sampling sites within the wetland during the operation period. In this study, the data from inlet and outlet of the wetland were compiled and analysed. The aim of this paper is therefore to estimate the removal efficiency of metals and metalloids using data on concentrations and flow and investigate the effect of wetland age on removal pattern. The elements with the highest removal efficiency were Al, As, Ba, Ca, Cr, Cu, Fe, Mn, Pb, V and Zn ranging from 95% for Pb to 65 % for Ca. The elements with the lowest reduction were B, Co K, Mg, Ni and S ranging from Co 56 % to 40 % for S. It was found that the removal efficiency was not related to inlet concentrations of the elements as the elements with high and low inlet concentrations were found in both groups. Analysis of reduction pattern also revealed that the group with higher removal efficiency showed fairly constant outlet concentrations during the study period, while the elements with lower removal efficiency demonstrated variable outlet concentrations. No statistical difference in removal due to age of the wetland was found. The study results showed that the wetland system has high removal efficiency of metals and metalloids and the removal pattern is not affected by age of the wetland. The influence on reduction due to leachate characteristics, wetland design and retention time will be discussed.

  • 17.
    Weisner, Stefan
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Environmental Science, Wetland Research Centre.
    Johannesson, Karin
    Linköpings universitet, Linköping, Sverige.
    Tonderski, Karin
    Linköpings universitet, Linköping, Sverige.
    Näringsavskiljning i anlagda våtmarker i jordbruket: Analys av mätresultat och effekter av landsbygdsprogrammet2015Report (Other academic)
    Abstract [en]

    Measurements of removal of phosphorus and nitrogen in created wetlands in agricultural areas in Sweden have been compiled and analysed. The results indicate the level of phosphorus and nitrogen removal that can be achieved in created wetlands in agricultural areas in Sweden. The results have also been used to develop new models for calculating removal of phosphorus and nitrogen in created wetlands in which measurements have not been done. Finally, these models have been used to estimate the removal effects that can be expected in the wetlands that have received financial support within the Swedish Rural Develop­ ment Programme in 2007–2013, and how much the transport of phosphorus and nitrogen to the sea will decrease due to the creation of these wetlands.

    The new results show that phosphorus removal has been underestimated in earlier measurements as well as in models used in previous evaluations. In individual well designed and located wetlands, a removal of 100 kilo phosphorus and 1 000 kilo nitrogen per hectare wetland area and year can be obtained. The new results also indicate that it should be possible to achieve a removal of 50 kilo phosphorus and 500 kilo nitrogen per hectare wetland area and year in wetland creation programs prioritizing wetlands that are located and designed primarily for nutrient removal. The costs are estimated to 100 SEK per kilo phosphorus and 10 SEK per kilo nitrogen, if 50 percent of the costs are allocated to biodiversity and other ecosystem services.

    Model calculations based on a selection of representative wetlands within the Rural Development Programme were scaled up to the 5 261 hectare wetland area that have been granted financial support during 2007–2013. The evaluation show that the Rural Development Programme will result in a reduced transport to local waters­ heds of about 25 tons of phosphorus and 200 tons of nitrogen per year. Therefore, the transport to the sea will decrease with about 18 tons of phosphorus per year and about 170 tons of nitrogen per year, corresponding to 1.9 and 0.5 percent, respectively, of the transport to the sea from agricultural land.

    Creation of wetlands within the Rural Development Programme has thus resulted in significant decreases of transports of phosphorus and nitrogen to inland waters and the coastal sea. However, a comparison of removal per hectare wetland area and year between what has been achieved within the Rural Development Programme and in individual wetlands suggests that the effect could be substantially increased with a better location and design of wetlands.

  • 18.
    Yang, Fan
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Mesophilic anaerobic digestion conducted in single unit reactor at increasing ammonia concentrations2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of mesophilic anaerobic digestion for treatment of organic wastes is a growing biotechnology for sustainable energy supply. Ammonia inhibition is a major problem in anaerobic digestion mainly when digestion of nitrogen-rich substrates such as livestock wastes and manure occurs. This paper provides a summary of research conducted on ammonia inhibition of the anaerobic process. An experiment with mesophilic digestions of swine manure was conducted in single unit reactors, which were controlled under different ammonia concentrations by addition of NH4Cl in different amounts. From the experimental results, it was shown that NH4Cl could be an effective chemical agent for removing foam and scum in the digester. Methane production was decreased with the increasing NH4Cl addition until a collapse was observed between 11.2 g NH4+-N/l and 13.2 g NH4+-N/l. Contrary to the findings in thermophilic digestion, a dysfunction of acidogenesis was also observed since both gas and methane production was delayed with increasing NH4Cl addition. These findings suggest different ammonia inhibition principles in mesophilic and thermophilic digestion. It was further indicated that methanogenesis could produce a high percentage of methane although gas production was inhibited.

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