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309 Uppsatser om Acid mine drainage - Sida 1 av 21

En geokemisk kartering över området kring Nasa silvergruva : Effekterna av historisk gruvdrift i svensk fjällmiljö

The aim of the study was to map the extent of Fe, Cu, Pb, As, Zn and S contamination in the area surrounding the Nasa silver mine. The mine operated between 1635 and 1810 with some prospecting performed in 1889, and has become infamous for the gruesome ways that the indigenous people were treated during the early years of operation. This study tested three hypotheses through a geochemical survey: 1) sulfide oxidation is still active in the abandoned mine, 2) the soil downslope of the mine is contaminated by mine drainage, and 3) the stream downslope of the mine is affected in the same way. All three hypotheses were valid, as the results showed that still, >200 years after mining operations ceased, signs of the historical mining are clearly visible in the surrounding environment. Acidic conditions were discovered in surface waters close to the waste rock piles, which indicates active sulfide oxidation.

Fröåtjärns föroreningshistoria : Utredning av hur metallbelastningen varierat över tid med hjälp av sediment som ett naturligt historiearkiv

The metal mining history goes thousands of years back. The downside of the mining industry is the large amount of tailings created during the mining operations. Drainage and leaching of heavy metals from these tailings may cause major environmental problems including Acid mine drainage and leaching of heavy metals. This study examines a pond located near an old mining site, where part of the old mining facility has been recently (1990) restored. The objective was to assess eventual metal contamination from historical mining and the recently performed restoration using a sediment core as a natural archive of historical metal inputs to the pond.

Finngruvan - Uppföljning av vattenkvalitet, analys avavrinning och recipienter i området efter gruvdrift

This thesis raises the problem with Acid mine drainage around the closed mine Finngruvan.The purpose of the investigation was to compare metal content in surface water in the areaand its catchments between year 2010 and 2003, also to make calculation of specific runoffand metal load, furthermore determine the recipients in the area. Surface water samplingwhere preformed at the same place as 2003 and also at a few other places of interest. Adigital elevation file were used in GIS to calculate the area of the watersheds in the region,observations in the field where also made. The collected data were used to make comparisons,calculations and conclusions. The result showed that the surface water 2010 had somewhatlower metal concentrations.

Geokemisk undersökning vid Rävlidmyrgruvan, Västerbottens län : provtagning, analys och förslag till åtgärder

The mining industry, in terms of ore excavation and metal production, is and has been important to the Swedish economy. In connection with the ore excavation process, large amounts of partly sulphidic waste are produced. When the metal sulphides are exposed to air and water they are eventually oxidised, which leads to the formation of acidic water with high concentrations of metal cations and sulphate ions, so called Acid mine drainage (AMD). This water may reach the nearest surroundings and cause negative environmental effects. By covering the waste with soil or water, the oxidation process can be minimised. At the Rävlidmyran mine in the county of Västerbotten open pit mining took place between 1951 and 1991.

Ekonomin i syrning av spannmål till mjölkkor :

In this dissertation I have tried to figure out if it possible to make any money on acid grain to feed cows through a case study. The method is a case study combined with a documentary research. At present the farm sell all grain in connection with harvest and buy it back continuously in the neighbourhood, I have compared that with an alternative where I invest in a construction for to store acid grain on the current farm. I have delimit me to only have a look on acid grain because I think that is one of the cheapest way too store grain in smaller aplenty. Before beginning with acid grain is it important to be versed in how everything works and the risk to keep on with acid grain. One disadvantage is that the acid grain is not possible to store more than 12 months with out acid it once again. It is also easy to get mould in the pasture if it is not acid enough.

Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam

Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in Acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as a complexing agent for heavy metals and in this way increase their mobility.

Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam : Chemical stabilization of mine waste with sewage sludge and calcium carbonate residues

Chemical stabilization of mine waste from Ljusnarsbergsfältet with sewage sludge and calcium carbonate residuesMine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolvedoxygen and precipitation, oxidation may occur resulting in Acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as complexing agents for heavy metals and in this way increase their mobility.

Markavvattningsföretagens geografi och konsekvenser i Trosaåns avrinningsområde

Agricultural drainage is widely used to manage the amount of water in the ground in order to improve conditions for cultivation. However the effects of drainage companies on water regimes are considerable leading to runoff changes such as altered stream flows, peak flows and water levels. In a greater extent this could imply an increased risk for floods along affected watercourses. This study analyzes the extension of agricultural drainage within the drainage basin of Trosaån in Sweden by ArcGIS mapping. In a statistical analysis, historical variation in streamflow in relation to mean precipitation and mean temperature are investigated for the study area.

Landvinning : scenarier för efterbehandling och gestaltning av Aitikgruvan, Gällivare

Open pit mining creates huge amounts of tailings and waste rock deposits. Due to it's content of sulphide minerals, predominantly pyrite (FeS2), there is a risk of oxidation and formation of acid water containing heavy metals, known as Acid Rock Drainage (ARD). To prevent the process of oxidation, the tailings and waste rock have to be reclaimed. The most commonly used methods of reclamation are a coverage of water or soil. Mining also results in a large-scale interference in the landscape that will make an eternal change of its appearance.

Dikesavståndets inverkan på såtid och skörd

All arable land in Sweden need a proper drainage for an effectively agriculture to take place. Of all arable land in Sweden, about 50% is naturally drained and 50% need artificial drainge. More than half of the tile drained area is in need of new drainage or renewed drainage. A good drainage improves farming and crop growth and increases the opportunity to achieve a high and safe harvest level. Future climate change and agriculture size rationalization will increase the need for good drainage. In this paper, two trials with three drainage distances, performed at Lanna experimental station, were analyzed using a mixed linear model.

Effekt av myrsyra och beta-laktamas på penicillin- och S. aureus-halt i mjölk till kalvar :

A sample of milk inoculated with S. aureus was treated with penicillin, and Antipen (a new commercial product containing penicillinase) was added. To another sample with S. aureus and penicillin, formic acid to pH 5 was added, and to yet another sample, a combination of formic acid and Antipen was added. Controls with no penicillin were treated in the same way.

Jordbruksdränering, kostnader och genomförande :

Underdrainage is a costly investment but often a necessity to maintain rationalized plant cultivation, one can also see underdrainage as insurance to successful plant cultivation. Late ripening crops, low yield and difficult tillage cultivation are examples on an insufficient drainage. (Kvarnemo 1983) A drained field rise in land price and the scheme of the tiled drains is seen as a value item. The interest for underdrainage among the farmers follows with shifting economic situations within agriculture and has for long time been low. A big part of the Swedish tiled drainage systems is since 1930 and ahead. Many of these tiled drainage systems need to be replaced or complemented. The life length of one tiled drainage system varies with maintenance but can still remain in good function after 75 years with correct management.

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.

Organic acids in liquid feed for pigs - palatability and feed intake

Fermented liquid feed is well known for its health promoting effects on piglets. High levels of lactic acid are desired in the feed together with low levels of acetic acid and certain biogenic amines. Limits for acetic acid have been suggested to be 30-40 mmol/kg to avoid a decreased palatability of the feed; however, few studies have been performed. The purpose of this trial was therefore to examine which levels of lactic acid and acetic acid that can be accepted in a fermented feed without affecting the feed intake and thus the weight gain of the pig. A total of 60 pigs (Yorkshire/ Hampshire) were used in a trial during two weeks, between 9-11 weeks of age.

En fjärran framtid : införande av digital teknik i gruvor

Traditionally, mining has been performed mechanically with implementation ofyesterdays (and older) data. Several mining companies have started to useautonomous technology and robotics in the production areas although the harshmining environments make it unsuitable for today's electronic equipment. Despite allthe obstacles along the way of digitization, there seems to be no end in sight as thisdevelopment continues. This thesis focuses on what the mining industry is aiming forand why the mining companies are interested in these technologies. The actors of themining industry can be found to have a vision for the future mine, a production with ahigher degree of digitization and resemblances to a factory.

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