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336 Uppsatser om Chemical Vapour Deposition - Sida 17 av 23

Återvinning av näringsämnen från hushållsspillvatten med omvänd osmos

Hammarby Sjöstad is a new district in Stockholm with high environmental standard. Stockholm Water Company evaluates a local wastewater treatment plant with cutting edge technology. The first step is an experimental treatment plant (Sjöstadsverket) with four parallel lines of treatment, each with a capacity to treat wastewater from 150 persons. Within the membrane technology subproject the possibility of using reverse osmosis (usually called RO) to regain nutrients is examined.Reverse osmosis separates the incoming water in a clean permeate and a concentrate that, as the name indicates, is a more concentrated version of the incoming water. Using this method in wastewater treatment, a solution high in nutrients can be obtained without the use of chemical precipitation agent and with no production of sludge.

Förändring av radiocesiumtillståndet i jordbruksgrödor i Gävleborgs, Västmanlands och Uppsala län efter Tjernobylolyckan samt en fallstudie med stallbalansberäkningar på en mjölkgård :

Several radioactive nuclides were deposited in Sweden after the Chernobyl accident in 1986. The greatest attention was given to 137Cs because of its relative long physical half life of about 30 years. 137Cs will be present in nature for more than 100 years before it has vanished completely. When radiocaesium decays to a stable end product ionizing radiation is emitted, which can cause cancer in humans that has been exposed to a high radiation dose. Radiocaesium behaves like potassium and is easily taken up into biological systems.

Strukturell konservering av måleri på duk Studie kring den långsiktiga stabiliteten hos Plextol D 360, Plexisol P550 och Beva 371

In the early 80s, several new synthetic materials have come to be used in the treatment of canvaspaintings, among them Plextol D 360, Plexisol P 550 and Beva 371. Today, many conservatorsfind the information about the long term sustainability of these binding mediums to beincomplete. Evaluation of synthetic materials is mostly done through clinical research, sometimesartificial aging is simulated. The correlation between artificial and natural aging is however notestablished, useful information can therefore be gained through evaluations of actualconservation treatments. The intention of this study is to find out more about how thementioned products perform over time in normal museum conditions.

Design av försöksanläggning för trycksatt rökgasrening vid oxy-fuelförbränning

Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

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.

Phosphorus in agricultural soils around the Baltic Sea : comparisons of different laboratory methods as indices for phosphorus leaching to waters

Eutrophication of the Baltic Sea is a serious problem. A major contributing factor is diffuse losses of phosphorus (P) from agricultural land in surrounding countries. In order to estimate P losses, environmental monitoring of small agriculture-dominated catchments is being carried out in most of these countries. Evaluation of the risk of P leaching to waters is usually based on chemical tests originally developed to quantify the amount of soil P available for plant production. The tests are performed in different ways in the different countries and a number of different extraction agents are in use.

Isolating microorganisms from marine and marine-associated samples : a targeted search for novel natural antibiotics

The search for antibiotic compounds from the natural environment has been going on for seven decades, ever since penicillin entered the market and antibiotic treatments became routine. The evolutionary pressure put on the pathogenic microorganisms induced a rapid spreading of naturally occurring resistance genes, leaving only the option of finding new antibiotics to treat the resistant pathogens. Microorganisms have been extensively mined for their biosynthetic abilities to produce biologically active compounds. To date, more than 23 000 microbial natural products have been discovered. The Actinomycetales are ubiquitous bacteria that have been used for antibiotic discovery for more than half a century, and over 10 000 natural products have been identified from the order.

FASTIGHETSPAKETERING : Alltid ett godkänt förfarande?

Chemicals are everywhere in todays society, in humans, animals as well as nature, and they are difficult to avoid. The chemical industry is regarded to be the fastest growing industrial sector, accounting for ten percent of the global economy. A large amount of chemicals are used to produce hygiene products and cosmetics, products that in Sweden only are consumed in quantities of 110 tons per day. Researchers find it increasingly difficult to determine which chemicals that are dangerous and which that are safe, and how they might affect us in the long run. Correlations have been found between chemicals, diseases and other health effects such as cancer, allergies, reproductive and endocrine disorders.

Återvinning av industriell restvärme som värdeskapande process : En fallstudie på SSAB EMEA i Borlänge

The industrial sector accounts for a large share of greenhouse gas emissions. To reduce its negative impact on the environment is crucial in the quest for a sustainable future. In discussions of the industrial sector's impact on the environment guidelines have been highlighted as a tool to assist the industries in their efforts to change the relationship between the consumption of energy and production. This by improving energy efficiency and a shift to the best available technology. During the past 30 years the steel industry has reduced its energy consumption per ton of steel produced by 50 percent.

Faror i varor : En studie av unga vuxnas medvetenhet om kemikalier i hygienprodukter och kosmetika

Chemicals are everywhere in todays society, in humans, animals as well as nature, and they are difficult to avoid. The chemical industry is regarded to be the fastest growing industrial sector, accounting for ten percent of the global economy. A large amount of chemicals are used to produce hygiene products and cosmetics, products that in Sweden only are consumed in quantities of 110 tons per day. Researchers find it increasingly difficult to determine which chemicals that are dangerous and which that are safe, and how they might affect us in the long run. Correlations have been found between chemicals, diseases and other health effects such as cancer, allergies, reproductive and endocrine disorders.

Förstudie till våtmark i Rimbo : Design för optimal hydrologi och kväverening

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.

Provtagning av trädkärnor för att bedöma föroreningsgraden av klorerade lösningsmedel i grundvatten

Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.The aim of the study has been to investigate whether the CAH-concentration in tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons.

Utvärdering av lufthalts- och nedfallsmätningar gjorda vid Korsnäsverken : Samband mellan miljöförbättrande arbete i pappers- och massaindustrin och föroreningar i närområdet

En nedgång har setts i Sverige och Europa när det gäller luftföroreningar de senast årtiondena. Nedgången beror bland annat på minskade emissioner från industrier, övergång från uppvärmning med olje- och kolpannor till fjärrvärme och förbättrad bränslekvalitet. Denna studie utvärderar lufthalts- och nedfallsmätningar gjorda i närheten av pappers- och massaindustrin Korsnäs i Gävle. Mätserierna startar vid sent 1970-tal och går fram till årsskiftet 2009/2010. Nedfall av stoft, sulfat, natrium, kalcium och lufthalter av svaveldioxid samt sot studerades.

Fireball 2 : Energieffektiv fiber produktion

The development within the textile industry is always ongoing with development of new andbetter textiles, which often mean the use of non-natural materials like polyester. This doesn?t lineup with the work shared around the world against an improved environment, so the idea came touse a form of linen fibers instead of polyester as the reinforcing material together with cotton.The idea was to use flax, linen of low quality, which is seen as a waste product and garbage inthe production of high quality linen and flax seed oil. This flax of low quality needs to beseparated before it can be used in cotton spinning machines. Fireball 2 is just that, a process toseparate flax fibers through the treatment of a technique called electrohydraulic discharge.The thesis works goal is to evaluate the Fireball 2 process ability to separate flax fiber.

Fosforavskiljning i reaktiva filter vid småskalig avloppsrening

An excessive input of nutrients to lakes and other water bodies has created a problem with eutrophication in Sweden. Untreated, or partially treated, domestic sewage is a major source for discharge of phosphorus (P), which is the nutrient most frequently responsible for eutrophication of most fresh waters and the Baltic Sea. The waste water can be cleaned by filter materials, which have a high P-retention ability and which after saturation may be used as fertilizers. Four potentially suitable filter materials were tested in batch- and column experiments in this study. In the batch experiments, the following materials were shaken with waste water in time series ranging from 5 seconds to 60 minutes: coarse (1-4 mm) and fine (0-2 mm) Polonite® (heated bedrock from Poland); Filtralite® (light expanded clay aggregates with limestone added before burning); water cooled blast furnace slag (BF-slag) and BF-slag mixed with 10% burned limestone.

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