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353 Uppsatser om Chemical precipitation - Sida 21 av 24
Årstidsdynamik för kvicksilver i ett sövattensediment :
The limit for mercury in fish, set by health authorities, is exceeded in about half of the lakes in Sweden. Methyl mercury (MeHg) is the most toxic form of mercury and accumulates in fish. Therefore transformation of inorganic mercury (Hg) to methylmercury (MeHg) is an important process that we need to understand in order to possibly counteract the negative effects of mercury in the environment.
The seasonal dynamics of mercury biogeochemistry is likely of great importance for the accumulation of MeHg in the aquatic food web. In thesis the chemical speciation and transformations of Hg and MeHg in bottom waters and sediments is followed in Ängessjön, a small lake located on the east coast in the middle of Sweden. The lake is not directly affected by any industrial pollution and concentrations of Hg in the sediment reflect the atmospheric deposition in this area, as well as processes taking place along the hydrological pathways from soil to lake.
Samples from sediment, bottom- and streamwater were collected in average every second month during the period Feb.
Kemikalier i kläder-En butiksunersökning om kunskap, värderingar och agerande
Syftet med den här studien är att ta reda på vilken kunskap och vilka värderingar som finns i klädesbutiker angående kemikalier i kläder och om ekologiska alternativ. Jag vill även undersöka på vilket sätt information kan påverka butikerna till att agera i linje med en hållbar utveckling. Särskilt vill jag undersöka hur butikernas företagskultur påverkar deras strategiska arbete. Jag har gjort en kvalitativ undersökning och intervjuat 13 butiksinnehavare i centrala Malmö. Först träffade jag intervjupersonerna i deras butiker, några månader senare ringde jag upp var och en för att se om de tänkt något på det vi samtalat om eller till och med gjort några förändringar.
De flesta av intervjupersonerna visste mycket lite om vad det finns för regler gällande kemikalier i textil, de hade dock viss kunskap om ekologiska kläder.
Markberedningens, planteringspunktens och behållardjupets inflytande på granminiplantors etablering i fält :
A new type of forest tree seedling, called mini seedling, has been developed by the University
of Dalarna in Garpenberg, Sweden. Compared to traditional containerized seedlings
that are grown for 1 ? 2 years, mini seedlings are grown for only 10 weeks. The mini seedlings
are small, easily planted, cost effective, and reduce the amount of chemicals used in
the nursery. Research has shown that mini seedlings tend to have higher overall survival
rates than traditional container seedlings.
Samspel mellan amerikansk blomtrips, Frankliniella occidentalis,och kruk-gerbera, Gerbera jamesonii :
Gerbera jamesonii is a plant with a large amount of pollen and various flower colours and a
favourite host plant for Frankliniella occidentalis. The best growing temperature for gerbera
is approximately 20°C. Frankliniella occidentalis or the Western Flower Thrips is a small
insect that has become an important pest in greenhouse cultivation all over the world. The
high temperatures in the greenhouse are favourable for F. occidentalis.
Är det möjligt att använda SCR-rening av rökgaserna vid inblandning av avfall i biobränslet?
Waste appears to be a low-cost fuel compared to biofuel. This Masters thesis was conducted for Vattenfall Utveckling AB and deals with how waste in the fuel affects the performance of a SCR-catalyst. Different mechanisms of deactivation were surveyed, focusing on the poisoning mechanism. A literature study was carried out, which was used as a reference when analysing the results.Small samples (9x2x2 cm, 64 pieces) cut out from a full-scale unused honeycomb catalyst were exposed up to 1500h in two different combustion plants, Johannes in Gävle (co-combustion) and Högdalen in Stockholm (waste-combustion). The activity was measured mainly at 300°C but also at 250, 350, 375 and 400°C.
Sustainable business practices : a review of eco-efficiency
The current demanding business environment requires corporations to act fast in finding effective solutions to problems given the myriad of challenges they face (Dyllick & Hockerts, 2001). The challenges include the impact of climate change on business practices, natural resource consumption, chemical pollution, technological change etc. Moreover, the forces of globalization, heightened concerns about the deteriorating quality of the physical environment and increased stakeholder power are also increasingly having a real influence on business practices (Rainey, 2008).
Since 1992, the World Business Council for Sustainable Development (WBCSD) has encouraged the adoption of the concept of ecological efficiency (eco-efficiency) to support business efforts aimed at addressing some of these challenges. The aim of eco-efficiency is to reduce the amount of energy and materials used in production processes to achieve economic and environmental benefits (WBCSD, 2000).
Giraffens blodtrycksreglering
Through previous studies during my education, I have experienced that chemical deicing road salt is a known problem, mainly in southern Sweden. Road salt causes damage to the environment and also damage to vehicles and structures such as bridges, etc. Road salt causes vehicles and steel constructions to rust, leading to increased costs for repairs of damage to structures. Road salt also causes damage to the plants and the economy to suffer, when plant material and soil needs to be replaced. In order to get closer to a solution, I put up three questions.
Bergerosion i utskovskanaler
Today?s climate changes will probably give rise to precipitation in Sweden, which will cause more floods in Swedish rivers. Many of the Swedish rivers are regulated and have lots of hydro-electro power plants. Higher floods in the rivers will give greater water loads on the dams, which mean that a higher discharge through the sluice gates and in the spillway channels is needed. High discharge of water in a spillway channel can create scour of the material in the channel.
Dagvattnets föroreningar som potentiellt hot för en god ekologisk och kemisk status i ytvattnet : En kartläggning av Vallentuna tätorts dagvattenhantering utifrån dess tillsynsbehov
The EU's Water Framework Directive aims to a long-term and sustainable use of our water resources and wants to ensure good water quality in Europe's water bodies. Discharge of polluted stormwater into receiving waters can be a threat to their ecological and chemical status. Municipalities are responsible for supervision of the environmental quality standards (EQS) and therefore need to gain knowledge of current stormwater management, the expected level of pollution emissions and possible appropriate purification steps to ensure that the goal of good water quality is achieved.This master thesis aims to provide this knowledge in the example case of Vallentunas urban area and wants to prepare future oversight so that it can be assessed how much the discharge of polluted stormwater into the local receiving water is a threat to its status. With the help of maps, aerial photographs, site observations and individual discussions those areas are mapped where appearance of moderate to highly polluted stormwater could be suspected. The degree of pollution at the discharge points is determined based on land use upstream and uses standard values according to the administrators assistance "Tillsyn av dagvatten" (MSL 2014).The study identifies 100 areas in need of supervision regarding their stormwater management.
Igensättning av långsamfilter i Östby vattenverk i Kramfors : studie av påverkande faktorer
Östby waterworks in the community of Kramfors has since 2003 had problems of fast clogging of the slow sand filters. As the clogging appears more often, they must be cleaned more frequently which has made the drinking water preparation difficult. Wintertime it has sometimes been impossible to clean the filters which has led to their closing and this has influenced the water quality negatively.The waterworks is a surface waterworks which takes its raw water from the lake Sjöbysjön. The water is flocculated and filtered in a contact filter with the flocculent EKOFLOCK 91. Thereafter it is alkalinized before it reaches the outdoors placed slow sand filters.
Grundvattensänkning till följd av järnvägstunnel genom Hallandsås : miljökonsekvenser relaterade till förändrad kväveomsättning i mark
This thesis was carried out to give some background information to a report of SLU (Swedish University of Agricultural Sciences) for the Swedish National Rail Administration (Banverket). The requested information was to provide basic data for an environmental impact assessment of the construction of the tunnel through Hallandsås. The aim with the thesis work was to discuss and quantify the leaching of nitrate and the emission of nitrous oxide from the soil at the groundwater level established through the tunnel project. The nitrogen related processes that could be affected were described and discussed. The different areas where a decreased groundwater level can cause changes in the nitrogen processes are the wet and moist areas.
Improving peri-urban home gardens in Hyderabad, India
Insufficient intake of vegetables is a reason for micronutrient deficiencies and malnutrition in developing countries. With urbanization, globalization and a growing world population it is of major importance to secure sufficient food supply for the world?s population. Part of the solution to increased food security among the world?s poor could be the introduction of vegetable home gardens, plots for small scale vegetable production which can provide households with sufficient vegetables as well as serve as an extra income source.
The study Improving peri-urban home gardens aims at examining the existence of vegetable home gardens in the peri-urban areas of Hyderabad, India.
Små skogliga vattendrag i Värmland - Generell beskrivning, förekomst av traktorspår samt spårens inverkan på bottenfaunan :
Modern forestry requires a high degree of machine traffic for clear felling and scarification operations. The machines most frequently used are big and the traffic often results in tracks on the forest ground. There are many small streams running through a forest, in connection to logging operations, machines might cross these frequently. These crossings could result in the erosion of fine particulate inorganic matter, which ends up in the stream. The aim of this thesis was to give a general description of small forest streams of order-one in the county of Värmland and to determine the frequency of machine tracks in small streams.
Riskbedömning vid Saltvikens kopparverk
AbstractAt Saltvikens copperindustry, which is located in the municipality of Oskarshamn, copper was refined from sulphiteore some hundred years ago. The ore underwent several steps in the process before the final product was received. These steps all had an influence on the environment through discharge of heavy metals. The area where the copper industry was located is today considered to be of specific national interest due to its valuable nature and cultural values, as well as its value for recreational outdoor activities. Therefore, it is important to determine the present level of contamination and if any transport of contaminants have occurred, and to identify the risks that are associated with the site both at present and in a longer time perspective.Thirtynine soil samples and 16 sediment samples have been analyzed.
Vägsaltets effekter på växter i urban- och offentligmiljö : ett växande problem
Through previous studies during my education, I have experienced that chemical deicing road salt is a known problem, mainly in southern Sweden. Road salt causes damage to the environment and also damage to vehicles and structures such as bridges, etc. Road salt causes vehicles and steel constructions to rust, leading to increased costs for repairs of damage to structures. Road salt also causes damage to the plants and the economy to suffer, when plant material and soil needs to be replaced. In order to get closer to a solution, I put up three questions.