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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Noise-induced hearing loss in a paper mill in KZN, South Africa

Viljoen, Christina Adriana 17 July 2008 (has links)
ABSTRACT It is well documented that repetitive exposures to high intensity sound can cause acoustic trauma to the ear resulting in hearing loss, and that occupational noise is a significant cause of adult-onset hearing loss. Research world wide has indicated a significant number of workers with hearing loss attributed to noise exposure. Noise-Induced Hearing Loss (NIHL) claims are responsible for the majority of occupational disease payouts. The study was undertaken in order to determine the extent of hearing loss due to noise exposure that could be ascribed to excessive exposure to noise, and to describe the noise-induced hearing loss by severity, type of work, and area of work and duration of service. The cross-sectional study included 466 workers employed in a pulp and paper mill in KwaZulu Natal (KZN) South Africa. It involved the assessment of 932 individual audiograms to diagnose noise-induced hearing loss and the calculation of the percentage loss of hearing from pre placement to the year 2005. Audiometry results were presented for noise-induced hearing loss in relation to area of work, duration of service, categories of severity and age group. The prevalence of noise-induced hearing loss in the pulp and paper mill was 21% (98/466) and with 79% (368/466) of workers whose audiograms returned results not indicating NIHL. 75 workers were excluded due to workplace transfers. Type of work, area of work and years of service correlated significantly with a diagnosis of noise-induced hearing loss. As a department, the wood yard (which included the wood chipping facility, maintenance workers and workers with 10 – 20 years of service) showed the most significant association. In categories of severity 16.7% of workers suffering from NIHL fall in the ≤ 5 Percentage Loss of Hearing PLH category. This study has confirmed the findings of others that noise exposure is a significant hazard in industry and an effective noise control programme is the only way to reduce the risk of NIHL. _____________________________________________________________________
2

An energy balance analysis for current and future production of paper at Mondi Dynäs paper mill : A development project of current and future scenarios for the steam and condensate network with proposals for enhanced utilization of energy

Svedin, Claes January 2015 (has links)
Mondi Dynäs is a pulp and paper producer in the north of Sweden close to the town Kramfors. Last year Mondi Dynäs produced 231,404 tons of Kraft paper. In order to increase their production to 300,000 tons of paper per year this study was done in order to investigate how the increased biomass flow would affect the generation of steam along with the steam and condensate balance. This study started with a mapping of the current steam and condensate balance for one winter period January – Mars and one summer period July – September 2015. The resulting balance is used as reference period for the development of the future steam and condensate scenario where Mondi Dynäs will achieve the targeted production of 300,000 tons of paper per year. The future model shows that the future production of paper will give an abundance of biomass since the generation of steam will be more than sufficient. For the winter period the venting of steam over roof could be derived to 11.9 tons per hour and 34.4 tons per hour during the summer period. This can be compared to the current situation where the winter period gave an average steam blow out of 8.7 tons per hour and for the summer period 13.1 tons per hour. To utilize the accumulated energy from these energy streams, three different scenarios was studied. The first scenario were a future installation of a backpressure turbine along with a condensing turbine section. The new turbine would be attached to the highest pressure level at 65.5 bar and have a backpressure exhaust at 20 bar which will give a power of 7.6 MWe. The second scenario included the implementation of a new condensing turbine with the current system design for the steam network and boilers. This turbine would be attached to the 3.5 bar network and give the electricity power of 1.9 MWe. The third scenario included the installation of a new bark dryer. This would give Mondi Dynäs the possibility to sell bark to an external actor on the energy market. From derived figures in the future scenario model it would be possible to sell 108,144 MWh of bark while running the bark boiler. Mondi Dynäs AB is recommended to add a new condensing turbine to their steam network. The new turbine would be able to produce 1.9 MWe and need a cooling water flow of 190 tons of water per hour. Derived figures for the investment shows a NPV of 0.6 MEUR and the IRR value of 31 %
3

Energy and material balances of wastewater treatment, including biogas production, at a recycled board mill

Assis Lana e Cruz, Igor January 2016 (has links)
Challenges surrounding energy have gained increased attention, which is not least reflected in the 2030 Agenda for Sustainable Development and the Sustainable Development Goals (SDGs). Energy issues have also become a pressing matter for most countries in the last decades. The reasons for this are not only related to the effects of the emission of greenhouse gases (GHG) from fossil fuels and their impact in climate change, but also span through other issues such as security of energy supply with geopolitical considerations and competitiveness of industry. To address these issues, a collection of public policies ranging from the international to local levels have been implemented. Sweden has historically had lower energy prices than its European counterparts, which has resulted in its industry having a relatively higher share of electricity in the total energy use by industry. The share of electricity accounts for 35% of total energy use in Swedish industry. This has led to efficiency measures being overlooked by industry, and the pulp and paper industry is by far the biggest energy user, with a share of 51% of the total energy use by industry. The variation of energy prices, and particularly electricity prices have obvious implications on the competitiveness of this sector. Production of biogas in pulp and paper mills has been gaining attention, and is now the target of an increasing number of scientific studies. The interest for this industry is not only related to security of energy supply and the environmental performance of the biogas itself, but there are also considerations regarding the biogas plant as an alternative to treat the large flows of wastewaters and other waste stream in this sector. There is an estimated biogas production potential of 1 TWh within this industry in Sweden, which accounts for 60% of the current biogas production in the country. Pulp and paper mills commonly rely on aerated biological treatment to deal with waste streams with high organic content This biological process has a high energy demand, and the integration of an anaerobic treatment, along with the use of the biogas for heat and electricity can yield a net positive energy recovery for the combined plant. This project analyses the current energy and material performance of an anaerobic biological treatment combined with an aerobic biological treatment in a recycled board mill. The anaerobic treatment is performed upstream of the aerobic one and removes most of the chemical oxygen demand of the wastewater. Energy and material balances for the plant are presented, and a comparison of the wastewater treatment plant running before and after the start-up of the biogas plant is made. The plant operation with the anaerobic digestion has shown an increased energy use of 9.4% coupled to an increased flow of wastewater of 7.7%. The average biogas production is 72 Nm³/h, which accounts for 440 kWh and is currently being flared. The introduction of AD has largely decrease the organic load in the aerobic treatment, by nearly 50%. This project ends with an optimisation model implemented with the optimisation tool reMIND to investigate potential optimisation strategies for the operation of the combined plant. The model has shown to be adequate to describe electricity use with mean error below 10%. For the biogas production, the mean error was of 16%.
4

Baseline survey and habitat analysis of aquatic salamanders in the Pigeon River, North Carolina

Maxwell, Nikki J 01 December 2009 (has links)
The Pigeon River was severely impacted beginning in the early 1900s by a paper mill located in Canton, North Carolina. The mill discharged chemical byproducts into the Pigeon River until 1992 when the paper mill modified their processes. As a result, water quality improved but the status of salamander species in the Pigeon River was unknown. Worldwide amphibian declines over the last 20 years have drawn attention to the need for more research and a better understanding of species-specific habitat relationships. There is concern about amphibian population declines because amphibians are critical to the balance of ecosystems and are considered exceptional indicators of environmental health. The objectives of this study were: 1) to conduct a baseline survey of salamander species composition in the Pigeon River watershed, 2) to determine if salamander populations differ above and below the Canton paper mill, and 3) to attempt to explain variance in salamander abundance, richness and diversity by comparing water quality and substrate characteristics among streams. Eight stations were examined on the Pigeon River, with four stations located above the paper mill and four stations below. We also chose three stations on each of four tributaries, Big Creek, Fines Creek, Jonathan Creek and Richland Creek. Snorkel surveys were completed in the summer of 2009. Five of eight species of stream salamanders were found that historically existed in Haywood County, NC: Eastern hellbender, Blue Ridge two-lined salamander, shovel-nosed salamander, black-bellied salamander and spring salamander. No salamanders were found in the main channel of the Pigeon River below the mill. Eastern hellbenders and Blue Ridge two-lined salamanders preferred substrates consisting of rubble and avoided bedrock. Percent rubble was the only variable retained in substrate models and was positively related to salamander abundance, richness and diversity. Conductivity, salinity, and water temperature were higher in the Pigeon River below the mill than at all other sites. Salamander abundance was explained by dissolved oxygen, pH, and stream width in water quality models. The results of this study suggest salamander abundance was negatively associated with the Pigeon River below the mill because of poor water quality and not habitat availability.
5

Baseline survey and habitat analysis of aquatic salamanders in the Pigeon River, North Carolina

Maxwell, Nikki J 01 December 2009 (has links)
The Pigeon River was severely impacted beginning in the early 1900s by a paper mill located in Canton, North Carolina. The mill discharged chemical byproducts into the Pigeon River until 1992 when the paper mill modified their processes. As a result, water quality improved but the status of salamander species in the Pigeon River was unknown. Worldwide amphibian declines over the last 20 years have drawn attention to the need for more research and a better understanding of species-specific habitat relationships. There is concern about amphibian population declines because amphibians are critical to the balance of ecosystems and are considered exceptional indicators of environmental health.The objectives of this study were: 1) to conduct a baseline survey of salamander species composition in the Pigeon River watershed, 2) to determine if salamander populations differ above and below the Canton paper mill, and 3) to attempt to explain variance in salamander abundance, richness and diversity by comparing water quality and substrate characteristics among streams. Eight stations were examined on the Pigeon River, with four stations located above the paper mill and four stations below. We also chose three stations on each of four tributaries, Big Creek, Fines Creek, Jonathan Creek and Richland Creek. Snorkel surveys were completed in the summer of 2009. Five of eight species of stream salamanders were found that historically existed in Haywood County, NC: Eastern hellbender, Blue Ridge two-lined salamander, shovel-nosed salamander, black-bellied salamander and spring salamander. No salamanders were found in the main channel of the Pigeon River below the mill. Eastern hellbenders and Blue Ridge two-lined salamanders preferred substrates consisting of rubble and avoided bedrock. Percent rubble was the only variable retained in substrate models and was positively related to salamander abundance, richness and diversity. Conductivity, salinity, and water temperature were higher in the Pigeon River below the mill than at all other sites. Salamander abundance was explained by dissolved oxygen, pH, and stream width in water quality models. The results of this study suggest salamander abundance was negatively associated with the Pigeon River below the mill because of poor water quality and not habitat availability.
6

GC-MS Screening and PCB Analysis of Sediment from Central Kattegat

Eriksson, Emma January 2015 (has links)
Five sediment samples were collected in Bua on the Swedish west coast, near two industries, a paper mill, and a nuclear power plant. The two industries use water in their processes and have long been associated with releases of different substances, such as PCBs, and other chlorinated compounds. The environmental impact by the two industries is believed to be significant. The aim of the project was to examine the sediments close to both the water intake and water output to determine if these industrial activities have in any way changed the composition of the sediments. The sediments were extracted by Soxhlet extraction, followed by a deactivated silica and an acidic silica clean-up and then analysed by using a gas chromatograph coupled to a mass spectrometer, (GC-MS) with electron ionization, EI+, mode used in full scan mode. Each mass spectra were analysed by comparing them to the NIST database from 1998. The results were inconclusive since the peaks were not properly resolved, causing a poor correlation to the NIST database. One batch was specifically analysed for polychlorinated biphenyls (PCB) by using an atmospheric pressure gas chromatograph (APGC) coupled to a mass spectrometer (MS). The PCB analysis provided accurate results, except for the Ringhals intake where the MS became saturated due to the high levels. The river Viskan also showed high levels of PCB. The congener pattern from PCBs found near Ringhals intake resembled an Aroclor pattern from Aroclor 1248. Since the Aroclor pattern is only seen in Ringhals intake, the source is most likely from the small harbour and not from either of the industries.
7

Återvinning av dryckeskartonger : En studie som syftar till att öka återvinningsgraden av Tetra Paks förpackningar i Indonesien / Recycling of beverage cartons : Increasing Tetra Paks recycling rate in Indonesia

Backlund, Per January 2014 (has links)
People of the modern world consume more than they ever used to do. Because of the close correlation between consumption and the amount of waste, the waste volume is also expected to increase. The purpose of this study is to examine if some measures in the recycling process from Sweden could be implemented in Indonesia. In fact, Indonesia is one of the countries in which the waste management system is struggling. Tetra Pak, one of the world leading producer of food packaging, is studied in this report. Tetra Paks recycling rate of their beverage cartons is relatively low, 8.42 %, in Indonesia compared with their recycling rate in other countries. To answer the purpose, information was collected from scientific reports, by interviews carried out in both Sweden and Indonesia and by study visits in Indonesia. The results of the study shows that there are measures which could be made in the recycling process to increase the recycling rate in Indonesia. School projects and deposit systems could increase the collection rate and a drumscreen and a buffertank could make the recycling process more profitable for the papermills. There is also some alternative end products which could make the whole recycling process more public visible. One of the conclusions of this study is that the paper mills should adjust their drumscreens, this to increase the fibre yield which is crucial for the recycling value. Another conclusions is that Tetra Pak should consider to initiate a recycling business by their own, in order to reduce the burden on the environment.
8

The history of the International Brotherhood of Pulp, Sulphite, and Paper Mill Workers from 1906 to 1929 a case study of industrial unionism before the Great Depression /

Voelker, Keith E. January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Description based on print version record. Includes bibliographical references (leaves 399-401).
9

From Broke to Finish: A History of the Eastern Fine Paper Mill, 1889 - 2004

Stevens, Amy L. January 2008 (has links) (PDF)
No description available.
10

Implementation of a novel pigment recovery process for a paper mill

Jortama, P. (Pirjo) 19 December 2003 (has links)
Abstract The objective of this study is to demonstrate an ecological and economic recovery process, which was developed and implemented at Stora Enso Oyj Fine Paper Oulu mill during the period 2000 to 2002. The ECO plant recovers the material called ECO pigment from the effluent treatment sludge and it can be used as a filler in multicoated fine paper production for art printing purposes. The ECO plant process consists of the following process stages. First, there is a separating phase for the recoverable material from fibres and other rejects, which is done with a wire washer. Then the fractionating of the recoverable material is performed with two-stage centrifugal cleaners. Chemical treatment with peracetic acid is used as a preservative and to increase the brightness of the ECO pigment a little. Then the recoverable material is stored in the pigment storage area and dosed to the paper machines as a filler. The rejects from the ECO plant are thickened in belt filter presses and then transferred to the bark storage area, where they are mixed with bark and combusted in a solid fuel boiler. The majority of the particles of the recovered ECO pigment were less than 45 μm; this size of particle accounted for 96.4% (on average) according to the studies made between June and December 2002. The use of ECO pigment is not found to cause more web defect problems on the base paper than before, according to the studies of the number of total web defects with the achieved particle size distribution and because the microbe content has been controlled. There are three sources from which the ash content of the base paper is composed after the start-up of the ECO plant, i.e. the broke, the virgin filler and ECO pigment. Therefore the use of ECO pigment partly decreases the need to use virgin filler. The ECO pigment was tested in the coating colour in pilot tests, and based on these results it could be used in the coating colour. The dry solid content of the ECO pigment has to be increased from the present level for the coating application.

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