This study examines the wastewater treatment system on BillerudKorsnäs integrated pulpand paper mill at Karlsborg, with focus on the effluent of suspended solids. Due to lowerregulatory limits for the emissions of suspended solids BillerudKorsnäs is looking forways to improve the efficiency of the wastewater treatment. Therefore, this study seeksto create a statistical model for the emissions of suspended solids and to find which factorsin the production, wastewater treatment and surrounding environment that affects theemissions. The purpose of the study is to extend the current understanding of the treatmentsystem to create a base for future decisions. The methods used for the modelling areElastic net regression and Random forest classifier, which were selected for the variableselection properties they provide. Unfortunately, the results show that the fitted modelscan only explain a small part of the variation of the emissions of suspended solids.The lack of fit in the models indicate that the current data is not sufficient to explain thevariation in the emissions of suspended solids. During the study deficiencies in the datacollection has been detected and improvements to overcome these deficiencies are proposedin the hope of creating more reliable data for the company and to create a betterbasis for future studies. / Denna studie undersöker avloppsvattenreningen på BillerudKorsnäs integrerade massaoch pappersbruket i Karlsborg, med fokus på utsläppen av suspenderade ämnen. Pågrund ut av sänkta gränser för utsläppen av suspenderade ämnen undersöker BillerudKorsnäsmöjligheter för att öka effektiviteten i avloppsvattenreningen. Därför försöker dennastudie att skapa en statistisk modell för utsläppen av suspenderade ämnen och undersökavilka faktorer i produktion, avloppsvattenrening, och omgivande miljö som påverkar utsläppen.Syftet med studien är att förbättra förståelsen för avloppsvattenreningen och attskapa beslutsunderlag för framtida förbättringar. Metoderna som används i modellernaär Elastic net regression och Random forest classifier, vilka valdes för deras variabel selectionegenskaper. Resultaten för modellerna visar att modellerna endast kan förklara enliten del av variationen i utsläpp av suspenderade ämnen. Det dåliga resultatet indikeraratt nuvarande data inte är tillräckligt för att skapa den typ av modeller som används. Understudien så har brister i datainsamlingen upptäckts, och förbättringar för att överbryggadessa brister är föreslagna med ändamål att göra insamlad data mer pålitlig och skapa enbättre bas för framtida studier.

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The production of pulp and paper is associated with the generation of large quantities of wastewater that has to be purified to avoid severe pollution of the environment. Wastewater purification in pulp and paper mills combines sedimentation, biological treatment, chemical precipitation, flotation and anaerobic treatment, and the specific combination of techniques is determined by the local conditions. Wastewater treatment generates large volumes of sludge that after dewatering can be incinerated and thus used for bio-energy production. Sludge is currently viewed as biofuel of poor quality due to its high water content, and some mills treat it solely as a disposal problem. Two strategies have been identified as feasible options to improve the energy efficiency of sludge management. One is drying using multi-effect evaporation followed by incineration. The other is anaerobic digestion of the wet sludge to produce methane. This thesis explores the energy balances of sludge management strategies in pulp and paper mills with special focus on anaerobic digestion. The first part consists of a system analysis, used to evaluate some wastewater treatment processes and sludge management, and the second part of empirical studies of anaerobic digestion of pulp and paper mill sludge. It was shown that the use of energy for aeration in aerobic biological treatment should be kept to the minimum required for acceptable quality of the processed water. Additional aeration for reduction of the generated sludge will only result in reduced energy generation in a subsequent methane generation stage. In the second part of the thesis, it is shown that anaerobic digestion is a feasible option for sludge management as it leads to production of high value biogas. Co-digestion with grass silage, cow/pig manure or municipal sewage sludge should then be used to counteract the low nitrogen content of pulp and paper mill sludge.

<p>Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent. Periods of high concentration of phosphorus is also of great concern. The aim of this study is to investigate the causality behind the sludge bulking, with the help of scientific literature and analysis of previously compiled data using multivariate data analysis. COD and nutrients present in the influent will also be surveyed to identify variations in concentration caused by the paper making process.</p><p>The scientific literature points toward low nitrogen and phosphorus levels as the major causes of the bulking sludge, as this leads to increased growth of filamentous bacteria to the detriment of the preferred flocculating species. A full scale experiment was conducted in an attempt to evaluate sufficient dosage levels of N and P to reduce this problem. The experiment has produced stabile results with low percentages of suspended organic matter and nutrients.</p><p>Evaluation of the previously collected data using Multivariate Data Analysis did not lead to any correlation between variables being found, other than the impact of sludge concentration on COD-reduction. No relevant explanation to periods of high phosphorus levels could be found neither in the scientific literature nor in the multivariate data analysis.</p><p>Bleaching of the paper pulp, with hydrogen peroxide and lye, results in a subsequent increase in COD concentration in the wastewater. The study shows an increased COD in the water approximately 12 hours after the increased dosing of these bleaching agents. Also the amounts of easily degradable COD increases following increased dosage of hydrogen peroxide and lye. The content of easily accessible phosphorus in the influent represents a minimum of 25 % and 20 % of the amount theoretically required for BIO1 and BIO2 respectively. The influent levels of nitrogen represents 33 % and 100 % for BIO1 and BIO2 respectively.</p><p>From this study it has been possible to deduce that a controlled dosage of nutrients in relation to the incoming level of COD, is of great importance to the efficient treatment of COD rich effluent in the systems under investigation at Hallsta Papermill.</p> / <p>Vid Hallsta Pappersbruk används stora mängder vatten vid tillverkningen av massa och papper. Det förorenade processvattnet renas i två separata anläggningar, BIO1 och BIO2, båda med biologisk rening av typen aktivt slam. Avloppsvattnets höga halter av kolföreningar, vilka analyseras som COD (Chemical Oxygen Demand), kräver extra tillsats av kväve och fosfor för att erhålla tillfredsställande reningsresultat. I den biologiska reningen uppstår periodvis problem med slamsvällning, något som resulterar i höga utsläpp av suspenderat material och organiskt bundna näringsämnen. Även perioder med höga fosforutsläpp förekommer. Syftet med examensarbetet är att genom litteraturstudier och analys av historiska data, med hjälp av multivariat dataanalys, utreda orsakerna till problemen. Även en kartläggning av variationerna i inkommande avloppsvatten med avseende på COD och lättillgängliga näringsämnen genomförs.</p><p>Utifrån information från litteraturen tyder problemen med slamsvällning ofta på bristande tillgång på kväve och fosfor vilket bland annat kan resultera i kraftig tillväxt av filamentösa bakterier. För att komma till rätta med problemen startades ett styrt försök med beräknade optimala doseringskvoter. Försöket resulterade i stabil drift för båda anläggningarna med låga utsläppsnivåer av både suspenderat material och näringsämnen.</p><p>Resultatet från utvärderingen av driftsdata med multivariat analys visar att slamhalten har betydelse för COD-reduktionen i BIO1. Någon förklaring till problemen med höga fosforutsläpp har inte framkommit vare sig ur litteraturstudie eller multivariat dataanalys.</p><p>Vid alkalisk oxiderande blekning av termomekanisk pappersmassa ökar den totala COD-koncentrationen i avloppsvattnet i samband med höjd dosering av blekkemikalier. Studien visar att en ökad COD-koncentration kan observeras i vattnet in till BIO1 ca 12 timmar efter förhöjd dosering av blekkemikalier. Samtidigt ökar andelen lättnedbrytbart COD till följd av ökad blekningsgrad. Kartläggningen av inkommande vatten visar att mängden lättillgängligt kväve i avloppsvattnet in till biologierna motsvarar ca 33 % och 100 % av det teoretiskt beräknade behovet för BIO1 respektive BIO2. För fosfor uppgår motsvarande till minst 25 % respektive 20 % för BIO1 och BIO2.</p><p>Under examensarbetets gång har det kunnat konstateras att dosering av närsalter i förhållande till inkommande mängd COD är av stor vikt för en väl fungerande rening av det COD-rika avloppsvattnet vid Hallsta Pappersbruk.</p>

Environmental contamination with heavy metals, especially of soils, has been a continuousproblem worldwide since the beginning of the industrial revolution. Heavy metal emissionshave increased continuously since 1900 and the metals accumulate in the environment. Pulpand paper mill factories, and factories which produce sulphuric acid emit heavy metals,among others lead (Pb), copper (Cu) and zinc (Zn). Results from previous studies showedthat the soils near factories had higher concentrations of these pollutants than the controlplace. In this study I want to determine the effects of industrial heavy metal emissions of onehistoric and one present industry on nearby soil heavy metal concentrations.Samples were taken near one historically heavily contaminated site, the old sulphite factoryin Rydöbruk (1897-1944) and near the present Stora Enso paper mill in Hyltebruk. As acontrol site, I compared these with Rocknen nature reserve area.At each site I took 6 soil samples, representing the top 15-20 cm of soil and organic material.Samples were analysed with an Atomic Absorption Spectrometer and the concentrations oflead, copper and zinc were determined per ashed dry material.I analyzed the samples at the laboratory using the guideline from the Swedish StandardInstitute for water analysis.The concentrations of the soil samples showed no significant difference between the naturereserve area and the industrial sites (One-way ANOVA). This was due to very variableorganic content within and between the sites.Organic content of the samples has a significantly effect on the metal concentrations for Pband Cu (Linear Regression test). In conclusion, metals can accumulate in the vegetation, andin case of Pb and Cu there is a correlation between their concentration and the amount oforganic matter. Therefore in future studies it is best if soil with very high organic content orvegetation is used to determine if forest soil near industries are affected by past or presentindustrial emissions of heavy metals.

MSc, Faculty of Science, University of the Witwatersrand, 2011 / A growing interest is on the biological remediation of pollutants with the added benefit of generating electricity in microbial fuel cells (MFCs). Therefore, the analyses of suitability and potential of full-strength paper mill effluent and cheese whey were separately investigated in such devices. The most promising effluent was selected for biofilm optimization studies. In the biofilm buildup studies, anodes were enriched with microorganisms inherent to whey for a period between one and three months before their application in reactors. Independently, pre-incubated electrodes which were two-month-old were used serially in four MFCs of seven days each. In the preliminary study, the maximum power densities were 24 ± 3 mW/m2 (0.02 % coulombic efficiency − εcb) and 16.7 ± 1.8 W/m2 (εcb = 3.7 %) in paper mill effluent and whey, respectively. Following a three-month acclimation of whey anodophilic microbes, the power increased to 1 800 W/m2 (εcb = 80.9 %) and 92.8 % total chemical oxygen demand (tCOD) removal after a single batch cycle in MFCs. In anode recycling experiments, the operation was characterised by power of 390 ± 21 W/m2 (εcb = 0.25 %) in the third anode reuse; whilst the second reactor cycle had the highest tCOD removal (44.6 %). The anodophilic microbial species identified in cheese whey were from the Lactobacillus genus. This study concluded that wastes can supply fuel for power generation with simultaneous remediation; whey had greater potential than paper mill effluent; and both continual acclimation of inherent waste microbes and anode recycling improved the performance of MFCs.

Seguindo a linha de pesquisa de novos materiais geotécnicos, na busca por soluções técnicas a partir do uso de materiais alternativos, o presente estudo avaliou sob enfoque geotécnico o comportamento do resíduo de uma fábrica recicladora de papel localizada no estado do Rio Grande do Sul, Brasil. O objetivo do trabalho consistiu em caracterizar o resíduo e identificar suas propriedades no que se refere ao seu desempenho mecânico e hidráulico, a partir de um programa de ensaios de laboratório. O resíduo in natura possui uma umidade de 256 %, sendo composto de matéria orgânica (de 40 a 45 %), cargas minerais (principalmente caulinita e calcita) e água. As análises para a determinação dos parâmetros de deformabilidade, resistência e condutividade hidráulica foram feitas utilizando-se como variável os valores de umidade de aproximadamente 190, 160 e 130 %. Os parâmetros de compressibilidade unidimensional das amostras do resíduo não apresentaram variabilidade significativa com a variação da umidade de moldagem, obtendo-se valores médios elevados para os índices de compressão (Cc) e descarregamento (Cd) e para os coeficientes de adensamento (Cv), indicativos da alta compressibilidade característica do material. Para a determinação dos parâmetros de resistência do material foram realizados ensaios triaxiais nãodrenados. O ângulo de atrito interno obtido foi de ф’= 53,5°. Durante os ensaios triaxiais foram realizadas medições da condutividade hidráulica antes da fase de cisalhamento das amostras. Os coeficientes de condutividade hidráulica, medidos na fase pré-cisalhamento, atingiram valores da ordem de 10-9 m/s. A capacidade de atingir baixos valores de condutividade hidráulica é uma característica relevante do comportamento deste material e indica a possibilidade de ser utilizado como um material geotécnico alternativo em substituição aos materiais convencionais utilizados em coberturas impermeáveis de aterros (cover liners). / Following the line of research of new geotechnical materials, aiming new technical solutions using alternative materials, the present research evaluated, under geotechnical understanding, the behavior of the waste sludge from a paper recycling plant in Rio Grande do Sul, Brazil. The objective of this research aimed the characterization and the identification of the waste properties – mechanical and hydraulic performance, through laboratory tests. The natural waste has 256% of water content, and is composed by organic matter (ranging from 40 to 45 %), mineral charges (mainly Kaolinite and Calcite) and water. The tests for the determination of deformability, strength and hydraulic conductivity parameters were carried out under 190%, 160% and 130 % of water content. The one-dimensional compressibility parameters of the waste sludge did not show a significant variability with the variation of the molding water content, where the average values were high for the compression (Cc) and swelling (Cd) coefficients as well as for the consolidation coefficient (Cv), which can be considered as an indicative of high compressibility (characteristic of the material). For the determination of the strength parameters of the material, it was carried out undrained triaxial tests. The internal friction angle was ф’= 53,5°. During the triaxial tests, measurements of hydraulic conductivity were performed, previously shearing. The hydraulic conductivity coefficients measured during the pre-shearing phase, reached values around 10-9 m/s. The capacity for reaching low values of hydraulic conductivity is a considerable characteristic of the behavior of this material, what shows the possibility of its use as an alternative geotechnical material substituting the conventional materials used as cover liners

Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent. Periods of high concentration of phosphorus is also of great concern. The aim of this study is to investigate the causality behind the sludge bulking, with the help of scientific literature and analysis of previously compiled data using multivariate data analysis. COD and nutrients present in the influent will also be surveyed to identify variations in concentration caused by the paper making process. The scientific literature points toward low nitrogen and phosphorus levels as the major causes of the bulking sludge, as this leads to increased growth of filamentous bacteria to the detriment of the preferred flocculating species. A full scale experiment was conducted in an attempt to evaluate sufficient dosage levels of N and P to reduce this problem. The experiment has produced stabile results with low percentages of suspended organic matter and nutrients. Evaluation of the previously collected data using Multivariate Data Analysis did not lead to any correlation between variables being found, other than the impact of sludge concentration on COD-reduction. No relevant explanation to periods of high phosphorus levels could be found neither in the scientific literature nor in the multivariate data analysis. Bleaching of the paper pulp, with hydrogen peroxide and lye, results in a subsequent increase in COD concentration in the wastewater. The study shows an increased COD in the water approximately 12 hours after the increased dosing of these bleaching agents. Also the amounts of easily degradable COD increases following increased dosage of hydrogen peroxide and lye. The content of easily accessible phosphorus in the influent represents a minimum of 25 % and 20 % of the amount theoretically required for BIO1 and BIO2 respectively. The influent levels of nitrogen represents 33 % and 100 % for BIO1 and BIO2 respectively. From this study it has been possible to deduce that a controlled dosage of nutrients in relation to the incoming level of COD, is of great importance to the efficient treatment of COD rich effluent in the systems under investigation at Hallsta Papermill. / Vid Hallsta Pappersbruk används stora mängder vatten vid tillverkningen av massa och papper. Det förorenade processvattnet renas i två separata anläggningar, BIO1 och BIO2, båda med biologisk rening av typen aktivt slam. Avloppsvattnets höga halter av kolföreningar, vilka analyseras som COD (Chemical Oxygen Demand), kräver extra tillsats av kväve och fosfor för att erhålla tillfredsställande reningsresultat. I den biologiska reningen uppstår periodvis problem med slamsvällning, något som resulterar i höga utsläpp av suspenderat material och organiskt bundna näringsämnen. Även perioder med höga fosforutsläpp förekommer. Syftet med examensarbetet är att genom litteraturstudier och analys av historiska data, med hjälp av multivariat dataanalys, utreda orsakerna till problemen. Även en kartläggning av variationerna i inkommande avloppsvatten med avseende på COD och lättillgängliga näringsämnen genomförs. Utifrån information från litteraturen tyder problemen med slamsvällning ofta på bristande tillgång på kväve och fosfor vilket bland annat kan resultera i kraftig tillväxt av filamentösa bakterier. För att komma till rätta med problemen startades ett styrt försök med beräknade optimala doseringskvoter. Försöket resulterade i stabil drift för båda anläggningarna med låga utsläppsnivåer av både suspenderat material och näringsämnen. Resultatet från utvärderingen av driftsdata med multivariat analys visar att slamhalten har betydelse för COD-reduktionen i BIO1. Någon förklaring till problemen med höga fosforutsläpp har inte framkommit vare sig ur litteraturstudie eller multivariat dataanalys. Vid alkalisk oxiderande blekning av termomekanisk pappersmassa ökar den totala COD-koncentrationen i avloppsvattnet i samband med höjd dosering av blekkemikalier. Studien visar att en ökad COD-koncentration kan observeras i vattnet in till BIO1 ca 12 timmar efter förhöjd dosering av blekkemikalier. Samtidigt ökar andelen lättnedbrytbart COD till följd av ökad blekningsgrad. Kartläggningen av inkommande vatten visar att mängden lättillgängligt kväve i avloppsvattnet in till biologierna motsvarar ca 33 % och 100 % av det teoretiskt beräknade behovet för BIO1 respektive BIO2. För fosfor uppgår motsvarande till minst 25 % respektive 20 % för BIO1 och BIO2. Under examensarbetets gång har det kunnat konstateras att dosering av närsalter i förhållande till inkommande mängd COD är av stor vikt för en väl fungerande rening av det COD-rika avloppsvattnet vid Hallsta Pappersbruk.

Through decades of development along the thriving economy, the paper mill industry in Taiwan has had substantial growth in both quality and quantity. However, the rising trend of corporate digitalization and paperless information transmission in recent years brought the paper industry a never-before-seen impact. Therefore, this research approaches the subject from the aspect of constructing a performance evaluation model for assessment of direct labor in the paper mill industry by using the Analytic Hierarchy Process (AHP), in expectation to provide a set of more subjective evaluation model to replace the objective, impression-based evaluation method traditionally used in the dominatingly small and medium enterprise centered paper mill industry. A subjective evaluation system will provide evaluated employees information on their performance and development; through such method, the company will be able to strengthen employees¡¦ core abilities and further upgrade the company¡¦s competitiveness to achieve the goal of sustainable development. Subjects of this research are 108 member companies of the Taiwan Paper Mill Industry Association. The survey study were conducted in two stages: The first stage focused on significance analysis; in which indicators that do not have significance to the performance of direct labor in the paper mill industry are deleted. The second stage interviewed 52 companies that are currently implementing performance evaluation systems. The screened performance evaluation indicators are then calculated by the Analytic Hierarchy Process to derive their relative importance and weight. Through analysis of the Analytic Hierarchy Process, we derived an evaluation form for assessment of direct labor in the paper mill industry. Through further study, we discovered that in the performance evaluation dimensions, the work performance dimension has the highest relative importance, professional knowledge/abilities second and personal quality last. Since the full evaluation developed in this research are statistically based, it can be not only provided as a reference for evaluation activities but also converted into an internal audit system for regular evaluation and perpetual improvement to constantly reinforce the company¡¦s competitiveness. This research was also implemented on a target case for empirical study. In which, an actual evaluation with the model developed in this study was carried out. Results of the performance evaluation were highly affirmed by the higher-level management of the experimented company. They consider that this evaluation model is highly interpretative and can be used for future performance evaluation.

In 2011, Texas experienced the worst drought in recorded history. This has escalated concerns regarding environmental flows needed to sustain freshwater and estuarine systems as human needs are addressed during drought periods. In this thesis, I analyze fish assemblages and water quality variables in order to observe the effects of drought in the lower Neches River below the saltwater barrier located upstream from Beaumont, Texas. Fish and water quality samples were taken during drought conditions during fall 2011 and summer 2012, after a season of rain. During fall 2011, sites surveyed above the barrier had lower salinity but similarly low dissolved oxygen (DO) levels compared with sites surveyed below the barrier. Salinity levels during fall 2011 were relatively high (reaching up to 15 ppt), whereas salinity during summer 2012 never rose above 1.5 ppt. For gillnet samples obtained during fall 2011, fish species richness was higher in December following a series of rain events than during drought conditions in October and November. Although fish species richness was similar between fall 2011 and summer 2012, species composition varied greatly. For seine samples obtained during summer 2012, species richness was higher during May and July (when the barrier was open) than during June and August (when the barrier was closed). Species richness was lowest for sites in closest proximity to a paper mill effluent discharge pipe located below the barrier. Also, species richness was higher at sites above the barrier than at sites below the barrier regardless of whether or not the barrier was closed. Multivariate statistical analyses of gillnet samples revealed a large amount of compositional overlap among fish assemblages, regardless of time period and location; however, analyses of seine samples revealed that fish assemblages above the barrier were different than those from samples obtained below the barrier and that fish assemblages varied based on time period. Results indicate that, during periods of low flow, water quality deteriorates in the Lower Neches River below the saltwater barrier. During these periods of environmental degradation, fish assemblages have reduced diversity and sensitive freshwater species decline in abundance, with some absent from survey samples.