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186 Uppsatser om Trace metals - Sida 2 av 13
Mineraliska material som reaktiva filter för avskiljning av tungmetaller från dagvatten
Highly polluted urban storm water from e.g. highways can contain large amounts of heavy metals that may cause harm if they are discharged into recipients. To remove the heavy metals a possible low-cost method that does not require much maintenance, could be the use of reactive filters with filter materials consisting of industrial residues or other cheap mineral based materials. Dissolved metal ions are removed by reactive filters through the processes of ions binding to active sites on the surface of the filter materials, or by formation of insoluble precipitates.The ability of CaO-treated granulated blast-furnace slag, iron oxide coated sand, olivine and nepheline to remove seven heavy metals (Cr, Cd, Cu, Ni, Zn, Pb and Hg) from urban storm water was studied. Initially batch experiments were performed where the effect of pH, dissolved organic carbon (DOC) and dissolved ions on the adsorption efficiency was studied.
Grundvattnets geokemi vid Gladhammars gruvfält, Västervik. Effekter av äldre tiders kobolt- och kopparbrytning
The municipality of Västervik, with support from Envipro Miljöteknik AB, is carrying out a main study of the minefields at Gladhammar. Mining of iron, copper and cobalt under different periods from the 16th century until the end of the 19th century has led to discharges of metals to the lakes situated downstream. The aim of the main study is to investigate the possibilities to reduce the environmental load on the surrounding ground and water caused by heavy metals from the mine. The present report is a part of the main study. The aim of the work is to investigate the geochemistry of the groundwater.
Retention av tungmetaller i en anlagd våtmark : studier av Vattenparken i Enköpings kommun
The aim of this study was to examine the amounts of heavy metals in the sediment of a wetland constructed for stormwater treatment. The wetland is called Vattenparken and is located in the city of Enköping. The heavy metals which were analysed were Pb, Cd, Ni, Zn, Cu, Cr and Hg. The total metal concentrations were determined using HNO3 chemical extraction. From 8 sampling sites 5 sediment cores were taken.
Limning av metallföremål
Uppsats för avläggande av filosofie kandidatexamen iKulturvård, Konservatorprogrammet15 hpInstitutionen för kulturvårdGöteborgs universitet2012:25.
Sedimentprovtagning av dagvattendammar som ett alternativ till flödesproportionell vattenprovtagning
Stormwater run-off from surfaces such as roads or rooftops is often polluted with heavy metals and nutrients. Many of these substances can cause great damage in biota if they end up in the recipient. In Sweden constructed wetlands and ponds for treatment of stormwater are frequently used, since research has shown that these treatment ponds are reducing stormwater pollution considerably to a low cost. The knowledge of these pollutant removal mechanisms and how follow-up and assessment of the ponds should be performed is still limited.To determine the pollutant removal efficiency of the stormwater ponds it is recommended that flow-weighted water samples are collected from both the inflow and the outflow of the pond. This method demands considerable resources of time and money for installations and analysis.
Askåterföring i Jämtland : biobränslets och askans innehåll av tungmetaller relaterat till markernas geokemi
Using biofuels from regeneration cuttings is becoming more common in Sweden. Ash from the combustion of biofuels contains many valuable nutrients and base cations. The Swedish Forest Agency recommends that ash should be recycled to clearings where biofuels have been removed, to avoid future impoverishment of Swedish woodlands. In Jämtland, in northern Sweden, a large quantity of biofuels are taken out from cuttings but ash recycling has not yet been tried. The aim of this thesis was to examine the conditions for ash recycling in Jämtland regarding to soil chemistry and heavy metal content in soil and biofuels.
Utvärdering av den gröna smileyn inom livsmedelsinspektion : En intervju och enkätstudie i Halmstads kommun
With a growing population on earth the amount of end-of-life vehicles (ELVs) and other scrap steel increases. The European Directive 2000/53/CE? requires a minimum of 95 % reuse and recovery and 85 % re-use and recycling no later than 1 January 2015, for end-of life vehicles. This imposes a need for more efficient recycling and recovery. Despite this shredder residue (SR) is commonly land filled.This report investigated the magnetic fines residue generated at Stena Metall shredder facility in Halmstad, Sweden.
Lakningsförsök med furubarksflis : en utredning om utsläpp av fenolföreningar samt metallsorption
The filters used today to purify water are often expensive and the need to find new filter materials is substantial. Studies of pine bark have shown that this is a material that may be used as an alternative to conventional filter materials, such as activated carbon. However, the study of pine bark has shown that a leakage of phenolic compounds may occur when using the material for water purification. Therefore, the purpose of this report is to investigate the release of phenols from pine bark, in order to evaluate the use of pine bark as a filter material. Another assignment is to investigate the amount of metals adsorbed by the filter material.
Recipientundersökning av Ensjön : Bedömning av sulfidmalmgruvan Enåsens eventuella påverkan på sjöns vattenkvalitet
Ensåsengruvan is a mine situated within Ljusdals municipality in central Sweden. Themine was in use from 1984 to 1991 and has since been undergoing a remediation program. Mine tailings from sulfide rich ore is a potential environmental hazard due to its tendency to cause acid waters and heavy metal leakage. Lake Ensjön is situated one kilometer from the mine area. Due to the hydrological conditions it was not expected to receive inflowing water from the mining area.
Riktlinjer för modellering av reaktorkylpumpar i TRACE
Examensarbetet är utfört vid Ringhals AB och riktar in sig på reaktorkylpumparna på reaktor tre vid Ringhals kärnkraftverk (R3). R3an är en tryckvattenreaktor och reaktorkylpumparna är vertikala enstegs centrifugalpumpar som tillverkats av Westinghouse.Bakgrunden till detta examensarbete är att Vattenfall AB vill öka kunskapen inom modellering av LOCA (Loss-of-coolant Accident) och har startat ett projekt för modelleringen av detta i den termohydrauliska koden TRACE. En viktig del i modelleringen av LOCA är hur reaktorkylpumparna beter sig när dom får hantera ett tvåfasflöde och då främst hur försvagad deras pumpförmåga blir.För att kunna göra en korrekt modell av pumparna i TRACE behövs pumpkurvor för samtliga pumpregimer för både enfasflöde och fullt försvagat tvåfasflöde samt en kurva för hur pumpen reagerar på olika ånghalter. För de pumpar som finns på R3 finns bara kurvor för fyra pumpregimer för enfasflöde, så i dagsläget är det svårt att göra korrekta analyser av pumpförmågan.Syftet med arbetet är att få fördjupad förståelse hur reaktorkylpumparna beter sig vid ett tvåfasflöde och hur detta på bästa sätt kan modelleras för R3s pumpar och målet är att analysera och ge modelleringsförslag på bästa sättet att modellera reaktorkylpumparna i samband med tvåfasflöde.Examensarbetet har delats upp i två delar. En litteraturstudie för att utreda vilka pumpdata som skall användas för att på bästa sätt efterlikna pumparna på R3 och vad som gör att pumparna försvagas.
Karaktärisering, utvärdering och avsättning av Stena Metalls magnetiska fines
With a growing population on earth the amount of end-of-life vehicles (ELVs) and other scrap steel increases. The European Directive 2000/53/CE? requires a minimum of 95 % reuse and recovery and 85 % re-use and recycling no later than 1 January 2015, for end-of life vehicles. This imposes a need for more efficient recycling and recovery. Despite this shredder residue (SR) is commonly land filled.This report investigated the magnetic fines residue generated at Stena Metall shredder facility in Halmstad, Sweden.
Undersökning av bindningsmekanismer vid pressning av metallaminat : Investigation of bondning mechanisms at the pressing of metal laminates
Increased understanding of the mechanisms that operate in conjunction with the welding of metal surfaces may help to improve existing manufacturing processes, and to enable new products and combinations of materials. The purpose of the project has therefore been to acquire a deeper understanding of what is happening in the bond for steel and for the factors that form the basis for a bond to develop between metals in the production of laminates by pressing. The merge has been done by pressing and the surfaces after the experiments have been studied in detail in the scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and with interferenceprofilometry in Wyko, to provide a greater understanding of the mechanisms that influence the bonding in the interface between metals. The project was limited to contain the materials Docol 1000, HyTens 1200, Aluminum AA3003 and a commercial steel. The parameters varied in the experiments to study their influence closer are temperature, pressure, heat treatment and pretreatment. This has been implemented by pressing with varying temperature and pressure.
Dagvattendammars reningseffekt : påverkande faktorer och metodik för statistisk modellering
Storm water is defined as runoff from precipitation such as rain or snow. It is collected in sewage disposal systems and since it mainly originates from urban areas it can contain high levels of heavy metals, nutrients and oil etc. Polluted storm water is currently treated by different methods such as wet ponds, constructed wetlands and filter strips. This study investigates these methods, which in earlier studies have shown to give varying results regarding their treatment efficiency.This thesis has been written on commission of SWECO VIAK and was aimed at studying those parameters that may affect the treatment efficiency of nutrients and heavy metals in storm water treatment facilities (STF:s). Through literature studies the dominating treatment processes in ponds and wetlands were examined.
Optimering av den kemiska reningen vid Fläskebo deponi
Landfill leachate contains a variety of contaminants and is created when rainwater percolates the landfill. For landfill management the leachate is the main issue that can cause problems to the environment. At the landfill of Fläskebo, Renova AB treats the leachate in a local treatment plant. The treatment consists of a chemical treatment step with chemical precipitation, flocculation, sedimentation and filtration, and a final step with a carbon and peat filter. Renova has to ensure that the condition of the leachate reaches the regulation set for the landfill before it is released to the recipient.
XRF-analys av förorenad mark : undersökning av felkällor och lämplig provbearbetning
X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements.The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed.This study has shown that a greater moisture content will give a lower measured concentration for the same sample.