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40 Uppsatser om Zinc - Sida 1 av 3

Elektrolytisk reduktion av zink vid reningsprocess

When cylinders for motor saws are manufactured there are high demands on the cylinders strength and wearing qualities. Aluminum is a material with low density and is used by Husqvarna AB for their motor saw cylinders. The aluminum is strengthening with nickel that is attached to the cylinders through electrolysis. When aluminum is in contact with oxygen a film of oxide is formed. To eliminate the oxide and to prevent formation of new oxide Zinc is used.

Rostfria stålkonstruktioner och rostskyddsbehandling av stålkonstruktioner enligt Eurocode

Steel is an excellent material to build with, but consideration must be given to the fact that unprotected steel corrodes, rusts, therefore, as a rule, the steel must be protected in some way. This can be done by reducing the tendency of the steel to corrode by using stainless steel or by treating the steel with a protection method. The two most common methods of protection are corrosion protection paint and Zinc coating. To determine the method, the corrosive category must first be evaluated and this is done in accordance to EN ISO 12944-2:1998.Stainless steel is available in many varieties but only some of them have properties that make them suitable for use as construction steels. There are many factors to be considered in the design of stainless steel to prevent corrosion from occurring.

Biochar as soil amendment in flow-through planters - for increased treatment of zinc roof runoff

In times of increased flooding, enhanced by climate change, polluted stormwater poses an increased threat to the environment through contaminated water entering waterways. Bioretention utilizes natural processes in soil and vegetation to treat pollutants and combat this threat. Biochar produced through pyrolysis, has a high cation exchange capacity (CEC) and could therefore increase treatment in bioretention systems. This research applies a literature review, interview, and a model to explore the benefits and disadvantages of biochar in order to specify a soil-mix through an understanding of the production process and preferred application rate. High purification through CEC, increased water holding capacity, and carbon sequestration being the benefits discussed.

Spårning av miljöstörande ämnen i Uppsala stads spillvattennät

To the sewer systems households, industries and other activities are connected. The wastewater is collected at treatment plants where a nutritious sludge is produced. The sludge does not only contain nutrients, but also hazardous substances originating from different activities in society. To reduce the flow of hazardous substances to treatment plants and to create a sustainable recycling of plant nutrients the Swedish Water & Wastewater Association has developed the certificate system REVAQ. This certificate requires a good quality of the sludge but also that the treatment plants maps the origin of the unwanted substances.

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.

The legacy of the mill : a metal polluted forest soil in Gusum

Soils in a metal contaminated site on Stångberget in Gusum in southeastSweden were investigated and compared to relatively unaffected soils a fewkilometres away. Pollution came from historical release of untreated flue gasesfrom a brass mill. The objective was to find information on how high the metalconcentrations are, if metals from the polluted soil affect the surroundings andif the metal contamination affects the microbial community. The soil wasinvestigated using several different methods, such as field XRF measurements,chemical analysis of metal, carbon and nitrogen content, pH, acid neutralizingcapacity, texture, soil depth, field leach tests, sequential extraction and microbialfunctional profiles. The study showed that copper and Zinc concentrationswere above Swedish Environmental Protection Agency guidelines for lesssensitive land use on the entire investigated area.

Växters förmåga att ackumulera metaller : Vass, bredkaveldun och gäddnate i Bergviks dagvattendamm

AbstractSurface-water includes different kinds of pollutants from traffic and roads. To prevent these pollutants to reach nearby lakes one can construct surface-water ponds on locations with heavy traffic. At Bergviks shopping centre in Karlstad, two ponds, one smaller and one bigger has been constructed in order to decrease the pollutant pressure from the receiving waters of Kattfjorden. Several heavy metals are essential for plants and animals in low concentration but when they occur in higher concentrations, they become toxic to the organism. The larger pond at Bergviks shopping centre has a sedimentation function so the heavy metals sink to the bottom thereby not releasing directly in to Kattfjorden.

Metaller i dagvatten - Effekter i recipient : En analys av koppar, kdamium och zink i dagvatten från en parkering i Halmstad, Sverige

When stormwater occurs near human activity the water gets polluted. The purity and composition vary widely depending on the types of activities in the area, the type of surface the water comes in contact with, precipitation and many more parameters. It has long been known that stormwater quality can affect both human health and the environment as stormwater is a major contributor to pollution of receiving waters.A human activity that has an impact on the environment in several different ways is traffic and stormwater is no exception. Airborne gases that react with precipitation, oil leaks and fuel systems that drops down on the ground, metals from brake linings and rubber particles from tire wear are some of the aspects you have to take into account when categorizing the relationship between traffic and polluted stormwater.In this project, stormwater samples from a parking lot in Halmstad, Sweden were collected and analyzed with an atomic spectrophotometer. The presence and relationship between copper, cadmium and Zinc with different rainfall parameters have been studied.

Dietary intake of zinc and iron within the female population of two farming villages in the Red River Delta, Vietnam

In many developing countries, among them Vietnam, contamination of agricultural land is a major issue that has public health implications. A fast growing population, rapid urbanization and industrialization have led to air and water emissions of potentially toxic elements (PTEs), such as cadmium (Cd). Earlier studies have shown that individuals with low iron (Fe) and Zinc (Zn) status absorb larger quantities of Cd than those of adequate nutritional status. The purpose of this study was to investigate and compare the Fe and Zn intake from the foods consumed by women (15-45 years) in selected households in two agricultural villag-es in the Red River delta in Vietnam. In one of the villages the residents were involved in metal (mainly Fe) recycling activity, whereas in the other village the residents had agricul-tural production as main source of income. Interviews, followed by food intake calcula-tions, were performed.

Beräkning av massbalanser för metaller i vatten samt miljöriskbedömning av Nerån vid Österbyverken i Östhammars kommun

Österbyverken is an industrial estate in Östhammars municipality in Uppland, Sweden. Many different activities have taken place on the estate the last 600 years. During the last 15 years both health and environmental studies have been made by different companies. At the most recent study a great increase of metals in Nerån, a river that runs partly through and partly next to the estate, was identified with mass balances. The purpose of this thesis is to accomplish a deepened study about the reasons for the increase of metals in Nerån.

Utvärdering av rörelsemönster hos öring (Salmo trutta) utifrån otolitmikrokemi

The classic view of trout (Salmo trutta) life history is that trout begins its life in freshwater, migrates to the ocean after about 1-4 years and then returns to freshwater to spawn. As trout fry have been caught at the mouth of the River Emån, near the Baltic Sea, researchers have speculated that some trout emigrate during their first year of life. The purpose of this study was to describe the variation in the length of time trout reside in freshwater before they migrate to the ocean for the first time. Another purpose was to investigate whether it was possible to discern where and how long the fish spent in freshwater and saltwater during different parts of their lives. Between 2007 and 2009, 23 adult trout were captured in the River Emån in southeastern Sweden.

Ledarskap & management i storskalig smågrisproduktion

This study has been done in order to map the supply of vegetarian and vegan food products in Sweden for business clients and consumers. A total of 665 food stuffs were found and classified into six categories. The biggest category was meat substitutes with 302 products and the second largest category was sandwich spreads with 150 different products. Within the remaining categories a varied number of products were found; 86 beverages, 64 cooking accessories, 34 milk free ice creams and 29 plant based yogurts. Of the meat substitutes were 28 only available for business clients.

Utbudet av vegetariska och veganska livsmedelsprodukter på den svenska marknaden : vilka produkter finns och hur är de berikade?

This study has been done in order to map the supply of vegetarian and vegan food products in Sweden for business clients and consumers. A total of 665 food stuffs were found and classified into six categories. The biggest category was meat substitutes with 302 products and the second largest category was sandwich spreads with 150 different products. Within the remaining categories a varied number of products were found; 86 beverages, 64 cooking accessories, 34 milk free ice creams and 29 plant based yogurts. Of the meat substitutes were 28 only available for business clients.

Tungmetaller i lakvatten : avskiljning med mineraliska filtermaterial

Four different kinds of filter-materials with reactive surfaces have been studied concerning their capacity to absorb heavy metals in leachate from a municipal waste deposit. The heavy metals studied were: lead, cadmium, copper, mercury, chromium, nickel and Zinc. The leachate contains high levels of dissolved organic carbon (DOC) and has a high pH-value along with a high buffer capacity. These characteristics of the leachate make it difficult to remove pollutants and require efficient filters. The filters that were examined in the report are blast-furnace slag with CaO, sand covered with iron oxides, olivine and nepheline.

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.

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