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221 Uppsatser om Nitrogen fixation - Sida 14 av 15
Ärtrev som substrat för biogasproduktion : En litteraturstudie och rötning i labbskala
Until 2020, 49% of Sweden's use of energy must derive from renewable sources. Greenhouse gases must as well decline with 40% compared to 1990 as a part of Sweden's 16 environmental objectives. Biogas is part of the effort to achieve these objectives, but as the demand for biogas increases, more substrates are needed to meet the demand. The purpose is to investigate the conditions for pea residue as substrate by performing lab-scale mesophilic digestion with different fractions and notch lengths and then to summarize pea residue as a substrate for biogas production. During anaerobic digestion, 1000 ml bottles were used as reactors for digestion.
Kvantifiering av föroreningstillskott från dagvatten inom skyddsområdet för Göta Älv : en simuleringsstudie med modellen SEWSYS
The river Göta Älv reaches between Vänern and Gothenburg and is the main raw water source for Gothenburg that supplies about 700 000 people with water. To protect and maintain a high water quality, continuously samples and water analyses are made throughout the river. In 1998 a protection area was founded between surte and Lärjeholm where the raw water intake is. This was made to increase the awareness of the importance to protect the water. However, there is a lot of contribution of untreated stormwater to Göta Älv within the protection area.Göteborg Water and Sewage Works commissioned this thesis where two areas, Tagene industrial area and Kärra residential area, with untreated stormwater outlets within the protection area are studied.
Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter
Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and
phosphorus in rivers, lakes and the sea, which results in unbalanced ecosystems with
eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from
on-site wastewater treatment from scattered households with unsatisfactory purification.
Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.
Styrdokument för kontorsbyggnation ur ett ekologiskt hållbarhetsperspektiv : Aspekter och argument
The construction and real estate industry represents a significant part of Sweden's total impact on the environment and mainly affects the following national environmental objectives: reduced climate impact, a good built environment and a non-toxic environment. By establishing internal rules, companies within the industry can reduce their environmental impact. SMT (AB Sandvik Materials Technology), a part of the industrial group Sandvik AB, has set a target that during 2014 develop a guiding document with special consider to the environmental impact during construction of office buildings, that they establish at the Swedish regional capital Sandviken, for both internal and external tenants. This study therefore aims to clarify which environmental aspects that the construction and real estate sector mainly are responsible for, and therefore should be part of a guiding document for a company for establishing office buildings, and to present arguments regarding the use of such a document. The study is based on literature studies and personal contact with other companies, in the form of e-mail conversations and a telephone interview.
Modellering av vattenflöden samt kväve- och fosforkoncentrationer från Krycklans avrinningsområde med HYPE-modellen
HYPE-modellen utvecklades som ett hjälpmedel för att uppfylla målet om att alla svenska vattendrag ska ha uppnått åtminstone god ekologisk status år 2015, enligt EU:s ramdirektiv för vatten. I HYPE-modellen delas avrinningsområdet in i markklasser, som definieras utifrån kombinationen av jordart och markanvändning/marktäckeklass. I modellen finns det många parametrar. Vissa av dem är generella för ett större område eller kan hämtas ifrån tidigare forskning, medan andra måste kalibreras för varje avrinningsområde. De parametrar som kalibreras beror i de flesta fall antingen av jordart eller av markanvändning eller marktäckeklass.Syftet i den här undersökningen var att kalibrera HYPE-modellen för ett mindre avrinningsområde samt undersöka avrinningsvägar och utvärdera den utförda kalibreringen.
Gödslade eller ogödslade mellangrödor som biogassubstrat?
Jordbruket står idag inför utmaningen att öka produktionen av biogas-substrat utan att öka konkurrensen om jordbruksareal för foder- och livsmedelsproduktion. Fånggrödor odlas idag för att reducera jordbrukets kväveläckage till vattendrag. Genom litteraturstudie, intervjuer samt fältförsök undersöktes potentialen för att använda fånggrödor som biogas-substrat (då som mellangrödor), samt huruvida biogaspotentialen förhöjdes genom en mindre kvävegiva i samband med sådden av mellangrödan. Från tidigare publicerad litteratur kunde ses att endast en del utav det upptagna kvävet i fånggrödan återfanns i markprofilen till nästkommande gröda. De två huvudsakliga källorna till kväveförluster var lustgasavgång samt läckage av lättomsättbart kväve över vintern, med varierande nivåer på kväve-förluster beroende på lokal och gröda.
Industriella avloppsvatten i Chile : Identifiering av problem samt förslag på åtgärder
Chile and Santiago are struggling with heavy environmental problems as a consequence of urbanisation and industrialisation. In the Santiago region the air is seriously contaminated and most of the rivers are classified as heavily polluted.The aim of this thesis is to survey the industrial fluid waste situation in the Santiago region and to make suggestions on technological improvements or process changes. The purpose is also to study five different enterprises more closely and to give more detailed suggestions for improvement. Another purpose is to summarize relevant Chilean legislation.Information, provided by the supervisory authority, about the release of industrial wastewater to rivers has been analysed. Deep interviews have been made with authorities and consultants.
Metoder för aktivitetstest av anammox och ammoniakoxiderande bakterier på bärarmaterial
I och med övergödningsproblematiken i Östersjön och Sveriges åtaganden i samband med Baltic Sea Action Plan kommer det i framtiden ställas högre krav på rening av kväve från de större avloppsreningsverken i Sverige.Anammox är processen där ammonium oxideras till kvävgas med nitrit som elektonacceptor. Anammox har under den senare tiden implementerats för rejektvattenbehandling i avloppsreningsverk runt om i världen. När anammox används för att rena ammonium krävs att ca hälften av inkommande ammonium oxideras till nitrit genom nitritation. Detta steg utförs av ammoniakoxiderande bakterier (AOB) vilka kräver en aerob miljö. Den kombinerade processen med anammox och nitritation kallas deammonifikation. På Sjölunda avloppsreningsverk i Malmö har en pilotstudie, i sammarbete med VA-teknik på Lunds Tekniska Högskola, startats för att undersöka potentialen i att implementera deammonifikation i huvudströmmen på reningsverket.
Är Lerbodaälven verkligen en problemälv? : undersökning av fosforhalter
Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report.
1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven?
The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.
Vallbrott med hjälp av grisar :
To investigate the possibilities for effective soil tillage, that could imply lower costs,
lower negative environmental impact and in addition a meaningful occupation for foraging pigs, a field experiment was carried out in Gränna, Småland, during growing season 2006.
The experiment contained two treatments that were repeated three times and were carried
out on a couch grass-infected fallow on a light soil close to Sweden?s second largest lake, Vättern. Ploughing was one treatment and pig rooting followed by ploughing, was the
other. The experiment was conducted according to the guidelines of organic growing and
seedbed preparation was done the same way in the two treatments. The pigs, three groups
of five half-year old Linderödssvin (an old Swedish breed), was encouraged to perform
an even tillage by strip-grazing, i.e.
Anaerob psykrofil behandling av hushållsavloppsvatten i UASB : Utvärdering av kapaciteten hos en två-stegs UASB-reaktor för behandling av hushållsavloppsvatten
Hammarby Sjöstad is a new district in southern Stockholm. A main objective with the Sjöstad project was to halve the environmental impact compared to other construction work. The environmental goals involve a halved water consumption rate, a local treatment of storm water and trials aiming to extract nutrients from the waste water. Sjöstadsverket is an experimental treatment plant used for testing new treatment processes for domestic waste water from Hammarby Sjöstad. The results are to be compared with the conventional process used at Henrikdals treatment plant today.
Identifiering av fosfatfosfors käll- och flödesfördelning i ett litet jordbruksområde
Eutrophication of lakes and streams are nowadays a well known environmental problem and implies an enrichment of the nutrients phosphorus (P) and nitrogen (N). Phosphorus is considered to be the most important component for the growth of aquatic plants and leads in too large quantities to an intensification of growth. Phosphate (PO4) is the fraction of phosphorus that can easiest be taken up by plants and thus have the greatest impact on eutrophication. Increased plant growth in lakes and unfavorable conditions for aquatic animals are two examples of negative consequences. A significant portion of the increased nutrient supply to nearby water can be derived to phosphate leaching from agricultural areas, where private sewers and agriculture is two main sources.
Effects of biogas residues on respiration and denitrification in arable soil : evaluation of methods, microbial activity and agronomic implications
Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.
En jämförelse mellan amplifierad singelmolekylanalys och selektiv agar vid kontroll av hygienisering av avloppsslam
Bringing back the nutrients from the city to the country is becoming increasingly important, as the world?s stores of nutrients get more exhausted. Sewage sludge is an unapplied resource, rich in plant nutrients, which could replace parts of the commercial fertilizers used in Sweden
today. Sewage sludge may contain large amounts of pathogens, such as Campylobacter and Salmonella, why use can cause severe spreading of infections, both to animals and humans. These pathogens have the ability to survive for a long time in soil and water and therefore
some sort of treatment of the sludge is recommended before use.
Utredning av reningsfunktionen hos Kungsängens dagvattendamm : en studie med flödesproportionell provtagning
Dagvatten kallas det regn- och smältvatten som rinner av från hårdgjorda ytor i stadsmiljön. Detta vatten för ofta med sig stora mängder av föroreningar som tungmetaller, näringsämnen och oljerelaterade ämnen, vilka kan göra stor skada om de når recipienter. För att rena dagvattnet och därmed minska föroreningsbelastningen byggs det allt fler öppna dagvattensystem som t.ex. våtmarker och dammar. Studier har visat att dessa system har hög reningseffekt och dessutom är de kostnadseffektiva.