Sök:

Sökresultat:

295 Uppsatser om Acid sulphate soils - Sida 1 av 20

Konduktivitet i vattendrag som indikator på sura sulfatjordar

Increasing attention is being given to Acid sulphate soils wherever they occur. The problems that leaching sulphate soils gives with significant lowerings of pH and mobilization of heavy metals influence large spectra of our society from fisheries to agriculture to construction. Mapping these soils is consequently of great importance and the methods of doing this is very much lacking in function and precision. This study was therefore carried out to investigate whether conductivity in running water can be used as a simple instrument to identify Acid sulphate soils in the catchment. 31 coastal streams in the county of Västerbotten were analyzed for different catchment properties such as occurence of marine sediments and basic water chemistry including conductivity and sulphate.

Förekomsten av sura sulfatjordar i Mälardalen : -en pilotstudie utförd åt SGU

Acid sulphate soils is a wide spread problem along the northern coast of Sweden. This is causing great damage through low pH and leaching of metals out into the streams. These soils are estimated to be found in several places in Sweden but also in many other areas in the world. One of these areas in Sweden that are believed to contain these sediments is Mälardalen. The purpose of this study is to evaluate the extension of the Acid sulphate soils in this area.

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.

Surhetstillståndet i bäckar uppströmskalkdoserare i Dalarnas län

The acid deposition of sulphur- and nitrogenoxides from combustion of coal and oil cause acidification that lowers pH and gives increased contents of metals and altered aquatic biodiversity in the stream. The liming of lakes and streams, which was introduced to resist the acidification, demand large economic resourses despite of the decreased deposition of the acidifyng substances. Some of the streams are influenced by the acid deposition, while others are naturally acidic. It is therefore importaint to separate the anthropogenically acidified waters from the naturally acidic, in order to optimize the use of governmental fundings for liming. This thesis aims to estimate the acidity status and impact of acidification on 24 catchments upstream liming dispensers, which is part of the liming activities at the County of Dalarna.The acidity status of the streams was classified according to the Swedish Environmental Protection Agency old classification system (Naturvårdsverket 1999) as very acid to acid, with small ability to withstand a pH-change (alkalinity) due to acid deposition.

Är kolrika jordar en källa till fosforläckage? : en sammanställning av data från 130 åkerjordar

Phosphorus (P) is an essential nutrient but a surplus could lead to eutrophication. Furthermore, the minerals used to produce the mineral phosphate is a non renewable resource. There are in other words several reasons to reduce the leakage of P and the agriculture is one important area to attend. The aim of this work has been to investigate if carbon-rich arable soils content contain more P than arable soils with low carbon content. Moreover it has been calculated if the carbon-rich soils could pose a risk of P leakage by comparing their delivery of P with the plant uptake. The work has consisted of compiling the results from former gathered and analysed soil samples of 130 Swedish arable soils. The fractions of P considered are water soluble P (Pw), ammonium lactate-extractable P (P-AL), hydrochloric acid-soluble P (P-HCl), organic ammonium lactate-extractable P (Porg-AL) and inorganic ammonium lactate-extractable P (Porg-HCl).

Frigörelse av kvicksilver och metylkvicksilver till bäckvatten under olika perioder efter skogsavverkning :

High levels of Hg in fish in Swedish lakes have been a problem along time in Sweden. The major concern is production and accumulation of the most toxic form of mercury; methyl mercury (MeHg). Consequently, in about half of our 83 000 lakes fish contain concentrations above the recommended limit for human consumption of 0,5 mg mercury per kg fresh weight (most of it in the form of MeHg). Consumption of fish containing too high levels of MeHg may cause problems for both humans and animals. Three major sources of MeHg in surface waters are: 1) runoff from terrestrial areas, 2) deposition from the atmosphere, and 3) internal production of MeHg in lakes and streams. The aim of this study was to investigate the effect of clear-cutting on the concentration of Hg and MeHg into draining streams.

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.

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.

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.

Odlingsstrategier på organogena jordar : en studie om beslutsfattande bland KRAV-anslutna lantbrukare

This study examines how farmers certified by KRAV face proposed regulations on organic soils put forward by KRAV economic association among others, and how they are affected economically. These soils are, from an environmental perspective, interesting as a target for production regulations as they cause greenhouse gas emissions through decomposition of organic material when cultivated. The regulations advocate that organic soils should be grown with pasture where soil cultivation is only allowed every fith year which implies that possible adjustments of cultivation have to be made in order to fulfill the regualtions. Collection of data have been made through a questionnaire sent out to 574 farmers certified by KRAV. The answers have been analysed using a decision making model and statistical findings suggest that proportion of organic soils, type of production, economic conditions and farmers? goals and values have an influence on whether the regulations and potential cultivation adjustments have been considered or not.

Concentration and offtake of trace elements and macronutrients in Italian ryegrass (Lolium multiflorum Lam.) and spring barley (Hordeum vulgare L.) grown on soils amended with water treatment residual sludge

Aluminium sulphate (Al2(SO4)3) is usually added during the drinking water treatment processin order to precipitate organic and inorganic material, resulting in aluminium-based drinkingwater treatment residual sludge (WTR). Since 2003 Swedish law no longer permits WTR tobe deposited in lakes, and there is an interest to explore the possibility to utilize WTR as soilamendment. The aim of this study was to examine the effects of WTR application on cropgrowth and concentrations of macronutrients and trace elements (including micronutrients andpotential toxic elements). A greenhouse pot experiment was conducted with three soils; a clayloam rich in phosphorous (P), a loamy sand rich in P, and a silty loam with a low soil Pconcentration, and two crop species Italian ryegrass (Lolium multiflorum Lam. cv.

Effekten på nedbrytningen av rötter vid tillförsel av ammonium sulfat i en granskog i sydvästra Sverige

Decomposition of organic matter is a critical process in the ecosystem, which involves many essential biotic and physical parts. Decomposition is therefore an important process both above and below ground. The rate of decomposition is dependent of many environmental factors for example: pH, moisture and supply of oxygen. The decomposition can therefore be affected by large scaled environmental influences, such as acidification and climatic changes. The root litter in the forest is in different ways affected by acidification, liming and manuering.

Fosforläckage från växtodling - orsaker och ågärder :

Phosphorus is essential to all plants and is taken up from the soil as the ion H2PO4 - (and to some extent HPO42-). Plant availability depends on, among other factors, the soil pH. In order to provide for plant available phosphorus, it is applied as mineral fertilizers and farmyard manure. However, that causes phosphorus leaching from arable land to surrounding surface waters and lakes and contributes to the eutrofication. There are three types of soils in Sweden that are at higher risk of contributing to phosphorus leakage.

Interferences during analysis of polyphenols in fruit juices

One of the most commonly used methods for analysis of polyphenols is the Folin-Ciocalteu (FC) method, where the FC reagent has been reported to interfere with some substances in fruit juices. The interfering substance that is present in the highest amount in most fruit juices is ascorbic acid. In this study, the total phenolic content (TPC) of three fruit juices was analysed by the FC method as well as with an enzymatic method with hydrogen peroxide oxidoreductase type II (HRP) for comparison. To investigate how the interfering ascorbic acid affects the TPC, juice samples were analysed after removal and addition, respectively, of ascorbic acid. The samples were analysed with HPLC both before and after the extraction phase of the FC method.

Effects of genotype, age and feed on the fat components of egg yolk

The aim of this study was to investigate if the hen?s genotype, age and diet affect fat components in egg yolk. The fat components measured were total fat content, phospholipids, cholesterol and the fatty acid profile. This trial involved 12 groups of laying hens housed in 8-hen cages enriched with perches, dust baths and nests. The genotype Lohmann Selected Leghorn (LSL) and the genotype Lohmann Brown (LB)was used.

1 Nästa sida ->