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8940 Uppsatser om Chemical precipitation system - Sida 1 av 596

Energieffektivisering i ett reningsverk för skogsindustriellt avloppsvatten genom förfällning av extraktivämnen

Pulp- and papermills expend vast amounts of water in order to produce pulp, paper and cardboard. Hence, they alsocreate vast amounts of waste water which has to be cleaned before it can be released into the receiving body of water. Insuch a wastewater treatment plant, tremendous amounts of energy are expended by the aeration in the biologicalcleaning process. This aeration is necessary to supply the microorganisms that shall decompose organic material withoxygen, which they need for their metabolism. The transfer of oxygen from the gas phase to the liquid phase isprimarily inhibited by surface-active substances in the waste water like resin acids or fatty acids.

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.

Riskbaserat provtagningsprogram för mikroorganismer i Gäddviks vattentäkt

Risk-based sampling program of microorganisms in the water source in northern SwedenAfter several disease outbreaks caused by parasites in the drinking water during the last years, it is more essential than ever to insure that the water supply companies have enough barriers to counteract the presence of microorganisms in the outgoing water. It is also discussed whether climate changes such as increased precipitation can have a connection to the increased cases of parasites in water sources. The water source at Gäddvik is Luleå municipality?s largest and provides drinking water to 64 500 of Luleå?s 74 000 inhabitants. The investigation of microorganisms in the water source, especially in the Lule River has not been as prioritized as the sampling of chemical parameters.

Bättre enskilda avlopp i Sigtuna kommun : möjligheter för bebyggelse i Odensala socken

There are around 855 000 on-site sewage systems in Sweden and some 1 800 of these are located in the municipality of Sigtuna. The Sigtuna local authority has set the goal that all sewage systems with insufficient function should be improved before the end of year 2010. A malfunctioning on-site sewage system may cause three main problems: spreading of diseases, discharge of eutrophicating compounds and wastage of resources. The municipality strives to reduce these problems already at the stage of granting permits for installation of on site sanitation systems. The municipality has recently adopted new guidelines, which demands certain minimum reductions for different compounds. The guidelines also state that it is preferred that neighboring house-owners cooperate in jointly built and operated sewage systems and that the system should be able to recycle plant nutrients.

Rening av lakvatten vid deponin Degermyran i Skellefteå kommun : Utvärdering av nuvarande reningseffekt och simulering av mängden bildat lakvatten under 2000-talets klimatförändringar

At Degermyran landfill, situated in the municipal Skellefteå, a leachate treatment system was installed in 2005. One of the aims of this study was to investigate how well the treatment system works by using data from chemical measurements made on the leachate before and after treatment. Further this study had the purpose of investigating how the predicted climate changes of the 21st century will affect the amount of leachate generated at Degermyran by using a modified version of Thornthwaites water balance model. The treatment system has the ability of reducing manganese by 90 %, nitrogen by 73 % och TOC by 79 %. By the turn of this century the amount of precipitation that percolates the waste at Degermyran will be between 254 and 298 mm, depending on the amount of greenhouse gases that will be released in the future to come.

Membranbioreaktorteknik- en framtida lösning på Lundåkraverket? : Membrane bioreactors- A future solution at Lundåkra wastewater treatment plant?

Membrane bioreactors (MBR) combined with biological phosphorous treatment (Bio-P) has been investigated if that could be an alternative to the future expansion with conventional active sludge treatment at Lundåkra wastewater treatment plant (WWTP) in the proximity of Landskrona, Sweden.The results showed that the surface demand in the biological treatment will be reduced with 67% with the MBR-alternative compared to a conventional activated sludge process. The nutrient removal in the MBR-solution was decreased or unchanged for nitrogen-, phosphorous- and organic parameters. However, the energy demand will increase with an estimated cost of approximately 1 million SEK annually. Moreover, the extra chemical consumption is estimated to cost 370 000 SEK annually.The disturbances caused by filamentous bacteria such as sludge dispersal could be resolved with MBR-technology because the membranes are not affected by these organisms. The Bio-P process combined with MBR-technology works if the wastewater recirculates from the membranes to an aerobic zone.In the proposal, there will be a new pre-treatment step, for instance hole screens.

Bedömningsgrunder och reningskrav för avloppsreningsverk, 25-2000 pe, i Laholms kommun

The aim of this project was to look into ten small sewer systems in the municipality of Laholm, in Sweden, in order to work out common assessment grounds for them. The sizes of the systems for purification of wastewater were within the range of 25 to 2000 population equivalents. Our method was to study literature, the laws and regulations applicable and the files at the municipality. The conclusion is that every sewer system is different and every situation is unique. We concluded that based on laws and assessment grounds sewer systems equal in size and pollution load ought to have similar demands attached to them.

Bevattning av lagrat virke vid svensk skogsindustri : omfattning och miljökonsekvenser

Most of the saw and pulp industries have stored wood nearby their production, the main reason is to have a continuous wood flow to the production. Wet storage of wood is of great importance to keep the wood quality. Without water sprinkling the risk of drying outand decomposition through biological activity increases significantly and will result in a negative effect on future production and quality. One drawback of wet storage of wood is the leaching of chemical substances into the surrounding recipient. The log yard run-off contains phosphorus, nitrogen, phenols and organic substances. These substances can cause problems for the surrounding environment. The main objective of this project is to gain an understanding of the wet storage used by the Swedish wood industry and estimate the environmental consequences that run-off water will have on the recipient.

Laboratory adjustment to the new regulation on classification, labeling and packaging of substances and mixtures.

The United Nations has, during many years, developed a model for a globally harmonized system for classification and labeling of chemicals, with the aim of it becoming a global standard. This system is implemented in the European Union through the CLP-regulation and is now working parallel to the existing directives until 1st of June 2015, when all the new classifications of substances and mixtures must be completed. The aim of this project was to adjust the laboratory to the new legislation, through inventory of stored chemicals, update the list of chemicals and perform self-classifications of mixtures. The work included handling of about 650 different chemicals with varying hazard classifications and search for information in corporate websites and chemical databases. This resulted in a new and complete list of chemicals stored and used in the laboratory and, in addition, an example of how to make a self classification of a mixture.

Klimatet på tre platser i Sverige 2071-2100 i jämförelse med Europas klimat 1961-1990 med fokus på temperatur, nederbörd och avdunstning : En analytisk studie från en simulering av Rossby Centres regionala klimatmodell, rca3.

Due to human influences on the climate an increase in Earth's mean temperature is today an accepted conception. With a rising temperature discussions have started how the climate in an area will change in the future. Equally interesting and important is it also to study the precipitation in an area. Precipitation is the factor, next to temperature, that affects most how a climate in an area looks like and feels. Since precipitation is connected to evaporation the latter parameter is also of interest to study.

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.

Immunohistochemical evaluation of antibodies for staining of mouse spinal cord and mouse neuronal cells

The United Nations has, during many years, developed a model for a globally harmonized system for classification and labeling of chemicals, with the aim of it becoming a global standard. This system is implemented in the European Union through the CLP-regulation and is now working parallel to the existing directives until 1st of June 2015, when all the new classifications of substances and mixtures must be completed. The aim of this project was to adjust the laboratory to the new legislation, through inventory of stored chemicals, update the list of chemicals and perform self-classifications of mixtures. The work included handling of about 650 different chemicals with varying hazard classifications and search for information in corporate websites and chemical databases. This resulted in a new and complete list of chemicals stored and used in the laboratory and, in addition, an example of how to make a self classification of a mixture.

Enkla kemiska processer inom förskolan : En kvalitativ intervjustudie om förskollärares uppfattningar och tankar om läroplansmålet enkla kemiska processer

The aim of this study was to investigate preschool teacher?s perceptions about the curriculum goal concerning simple chemical processes. The result was based on narratives received by a qualitative study and semi-structured interviews of six preschool teachers. The results of the study showed that preschool teachers perceive that they actually are working in a relatively small scale with simple chemical processes and they do not really know what simple chemical processes are, and do not feel very familiar with the subject. Water, dough, mud, paint and baking were the most common activities that were used when working towards the curricular goal. However, it was never explained to the children that it was simple chemical processes they were working with during the activities, neither was it discussed among colleagues because of the uncertainty about the concept.

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.

Optimering av blekeriet i CTMP-linjen vid Rottneros Bruk

At Rottneros pulp mill mechanical pulp is bleached with hydrogen peroxide. The changes of bleaching chemicals that are used for different grades are taken from bleaching tables; however these tables are old and need to be updated. The purpose of this thesis was to be the basis of new documentation.In this thesis three pulps where studied with the aim to find the optimal bleaching chemical changes (total NaOH/VP-quote) for each pulp. The pulps were taken from the filter before the bleaching tower and the pulps were bleached in the lab. The most important pulp property in this study was the brightness and how that was influenced by the chemical dosages.

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