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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.
31

Assessing industrial pollution by means of environmental samples in the Kemi-Tornio region

Pöykiö, R. (Risto) 29 November 2002 (has links)
Abstract The results of the comparison of various dissolution methods for sulphur showed, that HNO3 together with H2O2 gave more complete decomposition of organic components than HNO3 alone. The acid procedure with a mixture of HNO3+H2O2 slightly underestimated the S concentrations of plant material. The losses of sulphur were the highest in the dry ashing digestion procedure (HF(DAC)). The Leco combustion technique with infrared (IR) detection gave good precision and accuracy for sulphur. For the determination of heavy metals in plant materials, both the HNO3 and HNO3+H2O2 procedures were especially effective for determining Cr. However, the HNO3+HClO4 procedure gave lower results, and HF and HF(DAC) procedures greater values for Cr. Sulphur accumulation in pine needles around the pulp and paper mills was clearly higher than other points in the Kemi area. For example, within a radius of about 1-1.5 km around the mills of Oy Metsä-Botnia Ab Kemi Mills, the sulphur concentrations for (C) and (C+1) needles were 28 % and 26 % higher than those in the corresponding background samples collected in Kuivaniemi at a distance about 25 km from Kemi. Pine needles do not appeared to be appropriate a method for monitoring the accumulation of Fe, Zn, V and Pb emitted from pulp and paper mills. However, the Ca concentrations in (C+1) needles in the vicinity of the Oy Metsä-Botnia Ab Kemi Mills was 48 % higher than the average Ca concentration calculated from all (C+1) needles; thus it is likely that part of the Ca in the needles is derived from the mills. The regional distribution pattern of Cr and Ni in mosses in the Kemi-Tornio area in 2000 showed clearly that the most polluted area (Cr > 200 μg/g and Ni > 20 μg/g) appeared to lie within a few kilometres of the ferrochrome and stainless steel works of AvestaPolarit Stainless Oy. Within this area, the Cr concentrations in mosses were 4-13 times higher than those outside the urban area of Tornio. The area most polluted by the opencast chromium mining complex (Cr > 200 μg/g and Ni < 20 μg/g) appeared to be in the immediate vicinity of complex. All the 95th percentile values for TSP (total suspended particles) in the mine area of AvestaPolarit Chrome Oy Kemi Mine were below the current Finnish air quality limit value of 300 μg/m3. However, the 98th percentile value exceeded the Finnish air quality guideline value of 120 μg/m3 at one monitoring site. According to leaching studies, the sum of calculated annual airborne pollution impact of water-soluble fraction (H2O) and environmentally mobile (CH3COONH4) fraction from the AvestaPolarit Chrome Oy Kemi Mine was Cr 1.2 kg, Fe 29 kg, Cu 63 kg, Ni 2.5 kg and Cd < 100 mg. According to the homogeneity studies of heavy metal deposition on TSP filters, Cr, Ni, Cu and Fe were non-uniformly distributed over the glass fibre filters. The rsd values varied between 5.4-33.9 % for Cr, between 7.5-35.0 % for Ni, between 3.6-25.9 % for Cu, and between 6.6-19.9 % for Fe.
32

Effect of paper mill ash on properties of expansive soils

Byiringiro, Alfred 04 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Expansive soils, one of the problematic soils, are encountered on all continents with exception of polar continents. Problems caused by their heaving and shrinking behaviour, particularly to light structures, have been reported from different countries to place large financial burden on developers. For this reason, many techniques have been developed and applied to prevent and/or remediate the damage caused by these soils. Soil stabilization with traditional chemical additives has been applied successfully since ancient times. In addition to traditional additives such as lime, cement, fly ash, etc., some non-traditional additives, such as polymer based products, salts, etc. have been used effectively for soil treatment. On the other hand, industries are increasingly challenged by waste management in an acceptable and environmentally friendly manner. In this regard, a number of researches have been done on using industrial waste for soil improvement purposes. The study and understanding of basic reactions involved in lime-soil stabilization persuaded many researchers to study the applicability of lime-rich products for soil treatment. Studies conducted by Khalid et al. (2012); Muchizuki et al. (2004) and Thacker (2012) showed that lime-rich products such as pulp fly and bottom ashes and CaO by-products, can be applied for soil stabilization. This research was thus performed to investigate the effect of lime-rich paper mill waste ash on expansive soil properties. Two commonly listed soil engineering properties namely volume change and strength were investigated. Soil strength was examined in terms of unconfined compressive strength (UCS), due to its correlations with a number of other soil properties, and the volume change in terms of free swell and swelling pressure. In addition to these two engineering properties, dry density and moisture content were also studied due to their involvement in structural design, as well as gradation, Atterberg limits and California Bearing Ratio (CBR). The choice of these properties was also influenced by the availability of a standard (ASTM D4609-08) specifically developed to assess the effectiveness of admixtures for soil stabilization. Two main types of materials were used namely three clay materials and paper mill ash. According to the index properties, commonly used for expansive soil classification, three clays were classified into low, medium and high degrees of potential expansiveness. The ash results from the combustion of paper mill sludge, sawdust, bark, coal ash and bituminous coal in a multi-fuel boiler for the purpose of electricity and steam production. The tests mentioned above were conducted on both untreated and treated clays and the results were compared. Since the study was carried out on this material based on the fact that it contains lime, the procedure applied for lime-soil stabilization was considered. In general, it was observed that ash-soil treatment has a number of effects similar to lime-treatment and almost all studied properties were enhanced for all clays. It can thus be concluded that the paper mill ash from a multi-fuel boiler can be efficiently used for expansive soil treatment. For optimum use of this material for expansive soil treatment, more tests and further researches have been recommended. / AFRIKAANSE OPSOMMING: Uitsettende gronde, een van die probleemtipe-gronde, kom op alle kontinente voor, behalwe die twee poolkontinente. Probleme veroorsaak deur uitswellende en inkrimpende gedrag van hierdie gronde, veral finansiële onkostes van ligte strukture is al in baie lande aangemeld. Vir hierdie rede is baie tegnieke ontwikkel en toegepas om skade wat deur hierdie tipe gronde veroorsaak is, te voorkom en/of herstel. Hierdie tegnieke sluit grondstabilisasie met chemiese bymengsels in, veral tradisionele bymengsels, wat met groot sukses in die verre verlede toegepas en na moderne tye oorgedra is. Bykomend tot tradisionele bymengsels soos kalk, sement, vlieg-as ensovoorts is ʼn aantal nie-tradisionele bymiddels soos polimeergebaseerde produkte, soute en ander produkte ontwikkel vir grondstabilisasie. Aan die ander kant raak industrieë toenemend daarmee gemoeid om afvalstowwe op ʼn aanvaarbare en omgewingsvriendelike wyse te bestuur. Op hierdie gebied is ʼn aantal navorsingsprojekte al uitgevoer om industriële afval vir grondverbetering te gebruik en sodoende die las op nywerhede te verlig. Navorsing is onderneem om die basiese reaksies wat onstaan tydens stabilisasie van grond met tradisionele en moderne middels te bepaal en om die geskiktheid van kalkryke produkte vir grondstabilisasie te ondersoek. Baie navorsing is uitgevoer wat aangetoon het dat kalkhoudende produkte soos pulp vlieg- en oondresidu-as, asook CaO neweprodukte gebruik kan word vir stabilisasie. Gebaseer hierop is hierdie projek onderneem om die effek van papiermeulas, verkry deur die verbranding in ʼn veelvuldige brandstof-stoomketel, op die gedrag van uitsettende grond te ondersoek. Tydens hierdie studie is twee algemene ingenieurseienskappe van grond, naamlik sterkte en volumeverandering ondersoek. Grondsterkte is geëvalueer in terme van eenassige druksterkte (EDS) as gevolg van ? deur middel van die korrelasie met ʼn aantal ander grondeienskappe, en die volumeverandering in terme van vry-swel en sweldruk. Addisioneel tot hierdie twee grondeienskappe is droë digtheid en waterinhoud ook bestudeer aangesien beide in struktuurontwerp betrokke is. Verdere eienskappe wat ondersoek is, is gradering, Atterberggrense en Kaliforniese drakragverhouding (KDV). Die keuse van hierdie eienskappe is beïnvloed deur die beskikbaarheid van ʼn toetsstandaard (ASTM D4609-08) wat spesifiek ontwikkel is om die effektiwiteit van bymengsels vir grondstabilisasie te evalueer. Hierdie standaard is deurgaans as verwysing tydens die projek gebruik. Daar is waargeneem dat as-behandeling van grond ʼn aantal effekte het soortgelyk aan kalkbehandeling, met die uitsondering van die droë digtheid en optimum waterinhoud van een van die gronde wat getoets is. Byna al die eienskappe wat ondersoek is, soos EDS, KDV, ensovoorts, is verbeter behalwe in die geval van die eerste klei waarvan die plastisiteitsindeks verhoog het en die grond meer plasties geraak het. Daar kan dus afgelei word dat papiermeule-as vanaf ʼn stoomketel wat veelvuldige tipes brandstof gebruik geskik is vir die behandeling van uitsettende grond. Om die optimumgebruik van hierdie materiaal vir die stabilisasie van swellende klei te bepaal, is meer toetse en projekte nodig.
33

The Effects of Pulp and Paper Mill Wastewaters on Phytoplankton Primary Productivity in the Red River, Louisiana

Holler, Jeffrey Dee 05 1900 (has links)
Responses of phytoplankton productivity in the Red River to unbleached pulp and paper mill wastewaters were monitored using in situ ^14C incubation. Preoperational studies, conducted prior to the discharge of mill wastewaters varied seasonally, but revealed similar productivity trends when compared with postoperational studies, conducted after mill discharges began entering the Red River. Carbon assimilation rates measured downstream of mill discharge were generally greater than upstream levels in both preoperational and postoperational studies. Selected physical, chemical, and biological parameters varied seasonally, but showed similar upstream-downstream values and preoperational-postoperational values. Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), and Biochemical Oxygen Demand (BOD_5) were positively correlated with postoperational productivity rates. Apparent color was negatively correlated with productivity rates.
34

Foulant adsorption onto ion exchange membranes

Watkins, E. James 16 June 1999 (has links)
No description available.
35

Does market concentration motivate pulp and paper mills to vertically integrate?

Wang, Gewei 02 September 2005 (has links)
Following sound economic theory, paper mills vertically integrate into pulp production, partly because internalizing the production of their inputs allows them to avoid transaction costs. Higher market concentration, a proxy of higher asset specificity and transaction costs, should encourage vertical integration in the pulp and paper industry. However, this relationship has not been robust in previous studies or in our replication with updated FPL-UW data. Upon a deeper analysis of the data, this study should clarify the mechanism by which transaction cost can induce vertical integration in this particular industry, which does not have well-defined intermediate goods markets. In order to specify the pulp markets where paper mills are likely to trade, we construct a mill-specific concentration measure as a substitute to traditional regional concentration measures. We also narrow our sample to mills producing free sheet paper, the most profitable paper grade in this industry. With such model refinement, this research exhibits a significantly positive correlation between transaction cost and vertical integration.
36

Förhållandet mellan COD och TOC i skogsindustriella avlopp / The relationship between COD and TOC inforest industrial wastewater

Johanna, Frid January 2015 (has links)
Under tillverkningsprocessen i massa- och pappersindustrin bildas avloppsflöden i flera olika steg. Ett av de miljöbelastande utsläppen utgörs av organiskt material. Organiskt material kan mätas som biokemisk syreförbrukning (BOD), kemisk syreförbrukning (COD) eller som totalt organiskt kol (TOC). Analys av COD inkluderar ofta miljöfarliga ämnen (till exempel kvicksilver). Naturvårdsverket har under flera år aviserat att analysen kan komma att förbjudas och därmed blir analys av TOC allt mer vanligt. EU:s referensgränsvärden anges dock i COD och design av reningsanläggningar utgår oftast från COD. Detta leder till att båda parametrarna kommer att fortsätta att vara aktuella. Med syftet att förbättra kunskapen om sambanden mellan COD och TOC för olika typer av avlopp inom massa- och pappersindustrin samlades jämförande serier över COD och TOC in från olika svenska bruk. Serierna analyserades med hjälp av regressions- och korrelationsanalys, för att sedan jämföras med medelvärdet av brukens COD/TOC faktorer (omvandlingsfaktorer). Studien innehöll även en del där information om analyser, förbehandlingar och övergången från COD till TOC samlades in genom intervjuer med personer ute på bruken. Som en avslutande del av projektet genomfördes ett laborativt arbete i mindre skala med främsta syfte att se hur konstant omvandlingsfaktorn var över tiden. Resultaten visade att korrelationen mellan COD och TOC ofta var hög men att omvandlingsfaktorn var beroende av typ av tillverkningsprocess och rening. Värdet på omvandlingsfaktorn varierade därför mycket mellan olika bruk och delströmmar. Bruk med tillverkningsprocesser som använder få kemikalier hade en mer lika omvandlingsfaktor sinsemellan än bruk med kemikaliekrävande processer. Dessutom gav en högre reningsgrad en lägre omvandlingsfaktor. Omvandlingsfaktorn föreföll varken påverkas av halten suspenderat material eller vara årstidsberoende. Dessutomvar den också relativt konstant över tiden. / The industrial production of pulp and paper generates wastewater in several different steps in the production chain. Organic material from the wastewater will have an impacton the surrounding environment. Biological oxygen demand (BOD), chemical oxygendemand (COD) and total organic carbon (TOC) are three ways to measure organicmaterial. When analyzing COD, harmful substances such as mercury are often used. The Swedish Environmental Agency has for several years forecasted that this analysis might be banned, and therefore analysis of TOC has become more and more common in Sweden. However, COD is often used as a design parameter when designing new wastewater treatment plants and the European Union’s reference values are given as COD. Hence, both parameters will continue to be used and both need to be taken into consideration. With the aim to improve the knowledge of the relationship between COD and TOC, data series with TOC and COD were collected. The data originated from several different Swedish pulp and paper mills, as well as from different types of waste water streams within each mill. The data series were analyzed using linear regression and correlation analysis, and then compared with the companies’ mean value of the ratio between COD and TOC (the conversion factor). Information about the shift from COD to TOC, and the analyzing methods and pretreatment methods was gathered by conducting interviews with employees at the different mills. The final part of the project was a laboratory study, with the main focus to examine if the conversion factor changed over time. The results showed that the correlation between COD and TOC often was high, but that the conversion factor depended on type of manufacturing process and waste water treatment. Mills with a low use of chemicals had a more similar conversion factor than mills with a more chemical demanding process. Furthermore, a high degree of purification resulted in a lower conversion factor. The conversion factor did not seem to depend on neither the content of suspended solids nor the time of the year. Additionally, the conversion factor was relatively constant over time.
37

Papper och lump : studier av kontinuitet och förändring i nordisk pappersindustri från 1600-tal till 1900-tal

Sjunnesson, Helene January 2006 (has links)
<p>. This thesis consists of an introduction and four previously published articles. The joint empirical focus is papermaking based on textile rags as fibre raw material. Furthermore the physical environment is central in the studies. The relationship between continuity and change is a prevailing theme. The thesis also pays attention to the use of different sorts of rags and to the connection between this kind of papermaking and the textile industry.</p><p>The overall purpose is to throw new light upon the paper industry based on rags – a part of early industry seldom mentioned in historical surveys of the industrialization process in Sweden. The aim is also to question the prevalent Swedish historical writing commissioned by the branch, characterized by set divisions between different phases of technical and industrial development, from simple craft to modern industry. One of these borderlines has been drawn between papermaking by hand and papermaking by machine, with the 1830s as the selected transition period. By studying and analysing changes in the traditional and seemingly static papermaking as well as the opposite: the traditional that has lingered in the new, this thesis shows that the course of events was much more complicated than that. An outcome of the studies is that the industrialization of the rag based paper industry has been a complex, uneven and prolonged process.</p><p>The first main part of the thesis consists of two Swedish regional studies centred on the province of Östergötland in a long-time perspective. The focus is mainly on the long continuity of papermaking by hand, which was carried out between 1628 and 1968. The study shows that a variety of types and sizes of mills regarding ownership, forms of production, location, paper qualities and techniques can be identified. Continuity was the dominating feature but within this framework technological and industrial change also took place.</p><p>The second main part of the thesis has a Nordic perspective and deals with a shorter period, mainly 1830-1870. One study examines the introduction of the paper-machine and the establishment of the first machine-made paper mills in Denmark, Sweden, Norway and Finland with special attention given to the Swedish mill Holmen in Norrköping and the Finnish Tammerfors mill, both situated in textile mill towns. A second Nordic study surveys hand-made paper mills founded during and after the time when the paper-machine technology had been established. As the studies show, two parallel development tracks were prevalent in the paper industry in the Nordic countries during the period 1830-1870 – papermaking by machine and papermaking by hand.</p><p>The first paper machines were imported from Britain to some of the oldest and largest paper mills. The introduction of the new technology led to changes in for instance the paper mill buildings and the organization of work regarding the papermaking process. In the preparatory and finishing work manual methods remained, and as before it employed mostly women.</p><p>At the same time, papermaking by hand continued to change and new hand-made paper mills were founded until as late as the 1890s. The study discusses possible explanations, among them growing markets for special qualities and combinations with other branches of industry.</p><p>All the studies show a connection between hand-made paper mills and wool mills on one hand, and machine-made paper mills and cotton and linen mills on the other hand. The paper industry based on rags could in fact be characterized as a kind of textile industry</p>
38

Technoeconomical evaluation of small-scale CO2 liquefaction using Aspen Plus / Teknoekonomisk utvärdering av småskalig förvätskning av CO2 med Aspen Plus

Svanberg Frisinger, Maja-Stina January 2021 (has links)
Syftet med den här studien är att göra en teknoekonomisk utvärdering av processer för förvätskning av CO2 med hjälp av Aspen Plus. Ett flertal förvätskningsprocesser från tidigare studier jämfördes och från dessa valdes två förvätskningsprocesser ut för fortsatta studier och simuleringar. Dessa två förvätskningsprocesser var ett internt kylt förvätskningssystem och ett externt kylt förvätskningssystem av Øi et al., Energy Procedia 86 (2016) 500-510, som kallats system A, samt av Seo et al., International Journal of Greenhouse Gas Control 35 (2015) 1-12 kallat system B. Dessa två olika processer simulerades för teknisk analys med hjälp av Aspen Plus. Aspen Economical Analyzer (AEA) användes för att göra den ekonomiska analysen. I dessa simuleringar användes ett massflöde på 45 ton/h inkluderat vatteninnehåll, i jämförelse med tidigare studier med högre massflöden runt 100 ton/h. Elektricitet-och kylbehovet undersöktes i ett flertal olika fall med varierande kyltemperatur mellan kompressorerna. Två fall med integrering av fjärrvärme samt två fall med en värmepump undersöktes också med varierande återgående temperatur på fjärrvärmevattnet. Detta gjordes för att undersöka hur mycket värme som kan tillvaratas från förvätskningsprocessen. Vidare bestämdes även investeringskostnader samt driftskostnader med hjälp av AEA. Från detta bestämdes även den årliga kostnaden av kapitalet, CAPEX, och kostnaden att förvätska CO2 räknades ut i form av €/ton.  Resultaten visade att integrering av fjärrvärme samt värmepumpar är användbart för att tillvarata på så mycket värme som möjligt från förvätskningssystemen. I de fall med en värmepump samt en återgående temperatur på 47°C i fjärrvärmenätet hade ett COP på 3.07 samt 3.15 för system A samt system B vardera. Kostanden att förvätska CO2 var 17.42 €/ton för system A samt 17.75 €/ton för system B utan använding av en värmepump samt en återgående temperatur på 47°C i fjärrvärmenätet. Vid integrering av en värmepump gick kostnaden av förvätskning upp till 20.85 €/ton för system A samt 21.69 €/ton för system B. Kostnaden av förvätskning dominerades av driftskostnader med kostnaden av kapitalet har en mindre påverkan. Utnyttjandegraden har även en stor påverkan på kostanden av förvätskning, då lägre kapaciteter visade sig leda till markant högre förvätskningskostnader. När intäkterna från fjärrvärmeproduktionen adderades till kostnadskalkylen, minskade kostnaden av förvätskning, speciellt för de system med en värmepump, där priset minskade till 10.26 €/ton för system A eller 10.98 €/ton för system B. I linje med tidigare studier pekar även dessa resultat på att det ekonomiska optimumet sammanfaller med energioptimum. Resultaten visade även att system A, det internt kylda systemet, hade den lägsta förvätskningskostanden och minsta elektricitetsförbrukningen med och utan värmepump, och därför är system A optimalt för småskalig CO2 förvätskning. / The aim of this study is to do a technoeconomical analysis on CO2 liquefaction systems using Aspen Plus. Several liquefaction systems from previous studies were compared, and from these, two liquefaction systems were chosen for further studies and simulations. These liquefaction systems were namely an internal liquefaction system and an external liquefaction system by Øi et al., Energy Procedia 86 (2016) 500-510, called system A and Seo et al., International Journal of Greenhouse Gas Control 35 (2015) 1-12, called system B. These systems were simulated for technical analysis using Aspen Plus, and Aspen Economical Analyzer (AEA) was used for economical studies. A small-scale liquefaction system was studied with a mass flow rate of 45 tonne/h including the water content, as compared to other studies with higher mass flow rates of around 100 tonne/h. The electricity demand and cooling demand were studied in several cases of interstage cooling between compressors. Furthermore, two cases of district heating as well as two cases of heat pumps were studied with varying return temperatures of the district heating water. This was done to study how much heat could be recovered from the liquefaction process. Furthermore, the capital expenses as well as the operating expenses were also determined using AEA. From this, the annual CAPEX and the cost of CO2 was calculated in terms of €/tonne CO2.  The results showed that district heating and heat pumps can be useful to recover heat from the liquefaction processes. The simulations that included a heat pump and assumed a return temperature of 47°C had a COP of 3.07 and 3.15 for system A and B respectively. The determined cost of production was 17.42 €/tonne for system A and 17.75 €/tonne for system B when not using a heat pump and a return temperature of 47°C in the district heating grid. However, when adding a heat pump the total production cost (TPC) increased to 20.85 €/tonne for system A, and 21.69 €/tonne for system B. It was also shown that the TPC is highly dominated by the operating expenses while the total capital investment has a smaller impact on the TPC. The capacity is also important for the TPC as lower capacities was shown to lead to significantly increased production costs. When taking the revenue streams from district heating into account the TPC was decreased, in particular for the systems including the heat pumps, where the TPC for system A was 10.26 €/tonne while for system B it was 10.98 €/tonne. In accordance with previous studies it was shown that the economical optimum is closely related to the energy optimum. It was concluded that as system A, the internal liquefaction system, had the lowest TPC and electricity input with and without the heat pump and thus it is the optimal configuration for small-scale CO2 liquefaction.
39

Effects of Pulp and Paper Mill Effluent on Stream Primary Productivity in the Lower Sulphur River, Texas

Davis, Terrence Marvin 08 1900 (has links)
Responses of periphyton and phytoplankton productivity in the lower Sulphur River (Texas-Arkansas) to bleach-kraft mill effluent (BKME) were monitored using in situ ¹⁴C incubation. Carbon assimilation rates measured downstream of mill discharge were substantially reduced from upstream levels. Periphyton and phytoplankton chlorophyll a concentrations remained relatively unchanged by the presence of BKME. Periphyton ash-free dry weight increased near the mill outfall, but decreased further downstream. Calculated productivity efficiencies (productivity:biomass) varied with variations in ¹⁴C rates. A laboratory bioassay was designed to determine the effect of BKME light-attenuation on photosynthetic rates of upstream Sulphur River periphyton and Selenastrum capricornutum Prinz. Pooled results of bioassay runs indicated a 20 per cent BKME concentration effectively reduced control ¹⁴C-assimilation levels by 50 per cent. The downstream reduction observed for in situ productivity was 5 per cent lower than that predicted by the color bioassay.

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