In this study, proton-exchanged (PE) waveguides in Z-cut LiNbO3 and 36¢X-Y LiTaO3 have been fabricated using octanoic acid. The XRD analysis shows that the proton-exchange mechanism is different for LiNbO3 and LiTaO3 substrate, which results in a different variation of SAW velocity. For the temperature coefficient of frequency (TCF) and insertion loss (IL), the absolute values of both increase with the depth of proton-exchanged LiNbO3 and LiTaO3 substrates. In addition, the rf magnetron sputtering method is adopted to deposit SiO2 thin films on LiNbO3 and LiTaO3 piezoelectric substrates. Then the interdigital transducers (IDTs) were fabricated on the bi-layer structure. The film thickness of SiO2 was varied in order to investigate its effect on SAW devices. From the experimental results, TCF of SAW filters increase with the increased thickness of SiO2 thin film. At last, SiO2 thin films were deposited on proton-exchanged LiNbO3 and LiTaO3 substrates, respectively. From the experimental results for the SAW properties on the SiO2/PE-LiNbO3 and SiO2/PE-LiTaO3 structures, it reveals that the TCF of SAW filters increases with the increased thickness of SiO2 thin films. And we can conclude that SiO2 thin films can compensate the TCF of proton-exchanged LiNbO3 and LiTaO3

Wnt signaling regulates critical cellular interactions throughout normal development and directs cell fate decisions of stem cells. Previous work by our lab implicates -catenin as an essential modulator of embryonic stem cell self-renewal and differentiation. Genetic studies in mice have demonstrated broad functional redundancies between the most downstream effectors of the Wnt signaling cascade, the T-cell factor / Lymphoid enhancer factor (TCF/LEF) family of transcription factors. Despite this, loss-of-function experiments suggest that -catenin reinforces the pluripotent state by mediating a TCF switch in which repressive TCF7L1 is replaced with activating TCF7. However, these experiments do not account for potential confounding functional compensation by other TCF/LEF factors. As such, I hypothesized that TCF7 and TCF7L1 are functionally redundant in mouse embryonic stem cells and bind a largely overlapping set of target genes and interacting proteins. In support of this notion, we demonstrated that both TCF7 and TCF7L1 were similarly able to restore the altered transcriptomic profile and differentiation deficits observed in mouse embryonic stem cells (mESCs) lacking all full-length TCF/LEFs. With the expectation that TCF7 and TCF7L1 recruit similar transcriptional co-regulators to a broadly overlapping set of target genes, we employed the unbiased techniques, ChIP-seq and BioID to test our hypothesis. We observed that regardless of the degree of Wnt signaling activity, TCF7L1 was more abundantly associated with chromatin than TCF7, and TCF7 and TCF7L1 regulate distinct target genes. We demonstrated that Wnt stimulation, simulated by GSK-3 inhibition, facilitates TCF7L1 interactions with transcriptional modulators such as the BAF and nuclear receptor co-repressor complexes, despite a reduction in TCF7L1 levels. Taken together, the work in this thesis provides new insights into the mechanisms of Wnt target gene regulation by the TCF/LEF factors. / Thesis / Doctor of Philosophy (PhD) / Stem cells are capable of giving rise to multiple different cell types and thus are able to generate all adult tissues. The identity of a cell is controlled by external signals that regulate internal programs encoded by our genes. The execution of the instructions in genetic programs is conducted by proteins called transcription factors that can turn different genes on or off, giving rise to distinct cell types. The T-Cell Factors and Lymphoid Enhancer Factor (TCF/LEFs) are a family of four transcription factors regulated by external signaling molecules called Wnts. By using the TCF/LEFs, Wnts establish gene outputs that determine the identity of cells throughout embryonic development and in adult tissues. However, the mechanisms used by this family of transcription factors to establish the programs controlling cellular identity remain poorly understood. Using genetically engineered mouse embryonic stem cells, we have uncovered new information about the mechanisms TCF/LEFs use to regulate gene function, identified programs controlled by TCF/LEFs, and discovered potential protein partners that work with TCF/LEFs to implement genetic programs. This thesis provides novel insights into the control of cell identity by the TCF/LEFs, which has implications for the numerous human diseases linked to abnormal Wnt-mediated signaling.

In this study, we use the reactive rf magnetron sputtering method with deposition parameters of RF power of 370W, sputtering pressure of 15 mTorr, substrate temperature of 400¢J, nitrogen concentration (N2/N2+Ar) of 30% and 40%, to deposit highly c-axis orientation AlN thin films on Z-cut LiNbO3 and ST-cut quartz piezoelectric substrate, respectively. The material characteristics of AlN films deposited on Z-cut LiNbO3 and ST-cut quartz substrate with different thickness were obtained by means of the analyses of XRD, SEM and AFM. Besides, the interdigital transducers (IDTs) were fabricated on the bi-layers structure. The AlN film thickness of piezoelectric bi-layers structure was varied in order to discuss its effect on SAW devices and the temperature coefficient of frequency (TCF) of AlN. From the experimental results, it reveals that the center frequency and TCF of SAW filters increase with the increased AlN thin film thickness. Besides it can be concluded that poly-crystalline AlN exhibits a positive temperature coefficient of frequency (TCF).

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 55-62).

<p>Both Notch and the Wnt pathways are key regulators in maintaining the homeostasis in the intestine. Defects on the key tumor suppressor adenomatous polyposis coli, APC a gene in the Wnt pathway is most frequently mutated in colorectal cancer. Previous studies have indicated that there is a crosstalk between these two pathways. We investigate if there is correlation by first using bioinformatics to find Lef1/Tcf sites in several of the Notch pathway gene promoters. Bioinformatically we found that a lot of the genes contained theses sites controlled by the APC's destruction target β-catenin. By using semi quantitative PCR and western blot we found that Hes 1, Hes 7, JAG 2, MAML 1, Notch 2, NUMB, NUMBL, RFNG and LFNG was downregulated in HT29 colon cancer cells carrying a vector containing wild type APC. All but JAG 2 contains at least one Lef1/Tcf site in their promoter region. The results were verified in HT29 cells transfected with siRNA against β-catenin. We also investigated what would happen to the Lef1/Tcf target gene program of the Wnt pathway, if the Notch pathway was inhibited with the gamma-secretase inhibitor DAPT. Results showed no downregulution of β-catenin or its target gene Cyclin D1.Taken together, these results demonstrate that the Wnt pathway can be placed upstream of the Notch pathway and regulates the latter through β-catenin and the Lef1/Tcf target gene program. However, preliminary results indicate that there is no regulation of APC/β-catenin by the Notch pathway.</p>

A síndrome dos ovários policísticos (PCOS) representa uma das endocrinopatias mais frequentes em mulheres em idade reprodutiva, cujas principais características clínicas são anovulação crônica e manifestações de hiperandrogenismo. Em conjunto com os distúrbios reprodutivos, as pacientes com PCOS apresentam, frequentemente, obesidade e resistência insulínica (RI). Além disso, mulheres com PCOS apresentam maior risco para diabetes tipo 2, dislipidemia e hipertensão arterial e a presença da obesidade pode exacerbar os distúrbios metabólicos associados com a síndrome. A patogênese da PCOS está ligada a maior susceptibilidade ambiental bem como fatores genéticos e esses fatores podem influenciar a apresentação clínica da doença. Variantes genéticas, como polimorfismos de troca de um único nucleotídeo (SNP) vem sendo associadas com alterações metabólicas e clínicas. SNPs no gene TCF7L2 já foram descritos associados ao DM2 2 e RI. Estudos até o presente momento apresentam resultados controversos em relação a variáveis metabólicas e sua associação com os SNPs deste gene em pacientes com PCOS. Outros genes também vem sendo estudados e sabendo que a resistência à insulina e obesidade são característica frequentes de pacientes com a PCOS, o gene FTO surgiu como um possível locus a ser estudado, já que diversos estudos mostram uma associação com esses fatores em outras populações. Até o presente momento estudos mostram dados controversos, possivelmente associados a diferenças entre etnias. Além disso, estudos em uma população latino americana de mulheres com PCOS ainda não foram relatados na literatura. No presente estudo, observamos que os polimorfismos do gene do TCF7L2 rs7903146 e rs11196236 bem como seus haplótipos, não estão associados com a PCOS, mas que a paciente ser portadora de pelo menos um alelo de risco mostra uma variação positiva de 5,87 cm na cintura, 10,7 mg/dl no colesterol total e 10,3mg/dL no LDL-c. Além disso, para verificar a associação do polimorfismo rs7903146 com PCOS realizamos um meta análise, incluindo 1892 mulheres com PCOS e 2695 controles. Os resultados sugerem que o polimorfismo no gene do TCF7L2 não está associado com o risco aumentando de desenvolver PCOS em difefentes etnias (Asiáticas e não Asiáticas). No que se refere ao gene do FTO, os polimorfismos estudados também não foram associados com PCOS, mas os resultados mostram um aumento nos níveis de glicose nas pacientes que possuíam pelo menos um alelo de risco tanto para o polimorfismo rs9939609 quanto para o rs8050136. Estes resultados em conjunto sugerem que a PCOS por ser uma doença multifatorial e multigênica é difícil encontrar um único SNP responsável pelo fenótipo completo da PCOS, mas os estudos de associação em diferentes genes podem contribuir com o melhor entendimento dos diferentes fenótipos, principalmente nas características metabólicas destas pacientes. / The polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive age women, whose main clinical features are chronic anovulation and hyperandrogenism. Together with reproductive disorders, patients with PCOS frequently have obesity and insulin resistance (IR). In addition, women with PCOS have a higher risk for type 2 diabetes, dyslipidemia and hypertension and the presence of obesity may exacerbate the metabolic disturbances associated to the syndrome. The pathogenesis of PCOS is linked to greater environmental susceptibility and genetic factors and these aspects may influence the clinical presentation of the disease. Genetic variants as single nucleotide polymorphisms (SNPs) have been associated to metabolic and clinical changes. SNPs in the TCF7L2 gene have been described in association with DM2 2 and IR. Studies to date are controversial in relation to metabolic variables and their association with the SNPs of this gene in patients with PCOS. Other genes have also been studied and knowing that insulin resistance and obesity are common characteristic in patients with PCOS, the FTO gene has emerged as a possible locus to be studied. Several studies show an association with these factors in other populations. So far studies show controversial data, possibly associated to differences among ethnic groups. In addition, studies in a Latin American women population with PCOS have not been reported in the literature. We have found out that the gene TCF7L2, polymorphisms rs7903146 and rs11196236 and their haplotypes show no differences between genotypes and haplotypes for clinical and metabolic variables. However, for each T (rs7903146) and T (rs11196236) allele added to the haplotypes, a variation of 5.87 cm in waist (P trend=0.01), 10.7 mg/dl in total cholesterol (P trend=0.03), and 10.3 mg/dl in LDL-C (P trend=0.01) was recorded. Also, to verify the association of rs7903146 polymorphism with PCOS we conducted a metaanalysis including 1892 women with PCOS and 2695 controls. The results suggest that polymorphism in the gene TCF7L2 is not associated to the increased risk of developing PCOS in different ethnicities (Asian and non- Asian). As regards the FTO gene, the studied polymorphisms were not associated to PCOS, but the results show an increase in glucose levels in patients who had at least one risk allele for the polymorphism rs8050136 and rs9939609. These results together, suggest that PCOS being a multifactorial and multigenic disease is difficult to find a single SNP responsible for the complete phenotype of PCOS, but association studies in different genes can contribute to a better understanding of the different phenotypes, especially in metabolic characteristics of these patients.

A síndrome dos ovários policísticos (PCOS) representa uma das endocrinopatias mais frequentes em mulheres em idade reprodutiva, cujas principais características clínicas são anovulação crônica e manifestações de hiperandrogenismo. Em conjunto com os distúrbios reprodutivos, as pacientes com PCOS apresentam, frequentemente, obesidade e resistência insulínica (RI). Além disso, mulheres com PCOS apresentam maior risco para diabetes tipo 2, dislipidemia e hipertensão arterial e a presença da obesidade pode exacerbar os distúrbios metabólicos associados com a síndrome. A patogênese da PCOS está ligada a maior susceptibilidade ambiental bem como fatores genéticos e esses fatores podem influenciar a apresentação clínica da doença. Variantes genéticas, como polimorfismos de troca de um único nucleotídeo (SNP) vem sendo associadas com alterações metabólicas e clínicas. SNPs no gene TCF7L2 já foram descritos associados ao DM2 2 e RI. Estudos até o presente momento apresentam resultados controversos em relação a variáveis metabólicas e sua associação com os SNPs deste gene em pacientes com PCOS. Outros genes também vem sendo estudados e sabendo que a resistência à insulina e obesidade são característica frequentes de pacientes com a PCOS, o gene FTO surgiu como um possível locus a ser estudado, já que diversos estudos mostram uma associação com esses fatores em outras populações. Até o presente momento estudos mostram dados controversos, possivelmente associados a diferenças entre etnias. Além disso, estudos em uma população latino americana de mulheres com PCOS ainda não foram relatados na literatura. No presente estudo, observamos que os polimorfismos do gene do TCF7L2 rs7903146 e rs11196236 bem como seus haplótipos, não estão associados com a PCOS, mas que a paciente ser portadora de pelo menos um alelo de risco mostra uma variação positiva de 5,87 cm na cintura, 10,7 mg/dl no colesterol total e 10,3mg/dL no LDL-c. Além disso, para verificar a associação do polimorfismo rs7903146 com PCOS realizamos um meta análise, incluindo 1892 mulheres com PCOS e 2695 controles. Os resultados sugerem que o polimorfismo no gene do TCF7L2 não está associado com o risco aumentando de desenvolver PCOS em difefentes etnias (Asiáticas e não Asiáticas). No que se refere ao gene do FTO, os polimorfismos estudados também não foram associados com PCOS, mas os resultados mostram um aumento nos níveis de glicose nas pacientes que possuíam pelo menos um alelo de risco tanto para o polimorfismo rs9939609 quanto para o rs8050136. Estes resultados em conjunto sugerem que a PCOS por ser uma doença multifatorial e multigênica é difícil encontrar um único SNP responsável pelo fenótipo completo da PCOS, mas os estudos de associação em diferentes genes podem contribuir com o melhor entendimento dos diferentes fenótipos, principalmente nas características metabólicas destas pacientes. / The polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive age women, whose main clinical features are chronic anovulation and hyperandrogenism. Together with reproductive disorders, patients with PCOS frequently have obesity and insulin resistance (IR). In addition, women with PCOS have a higher risk for type 2 diabetes, dyslipidemia and hypertension and the presence of obesity may exacerbate the metabolic disturbances associated to the syndrome. The pathogenesis of PCOS is linked to greater environmental susceptibility and genetic factors and these aspects may influence the clinical presentation of the disease. Genetic variants as single nucleotide polymorphisms (SNPs) have been associated to metabolic and clinical changes. SNPs in the TCF7L2 gene have been described in association with DM2 2 and IR. Studies to date are controversial in relation to metabolic variables and their association with the SNPs of this gene in patients with PCOS. Other genes have also been studied and knowing that insulin resistance and obesity are common characteristic in patients with PCOS, the FTO gene has emerged as a possible locus to be studied. Several studies show an association with these factors in other populations. So far studies show controversial data, possibly associated to differences among ethnic groups. In addition, studies in a Latin American women population with PCOS have not been reported in the literature. We have found out that the gene TCF7L2, polymorphisms rs7903146 and rs11196236 and their haplotypes show no differences between genotypes and haplotypes for clinical and metabolic variables. However, for each T (rs7903146) and T (rs11196236) allele added to the haplotypes, a variation of 5.87 cm in waist (P trend=0.01), 10.7 mg/dl in total cholesterol (P trend=0.03), and 10.3 mg/dl in LDL-C (P trend=0.01) was recorded. Also, to verify the association of rs7903146 polymorphism with PCOS we conducted a metaanalysis including 1892 women with PCOS and 2695 controls. The results suggest that polymorphism in the gene TCF7L2 is not associated to the increased risk of developing PCOS in different ethnicities (Asian and non- Asian). As regards the FTO gene, the studied polymorphisms were not associated to PCOS, but the results show an increase in glucose levels in patients who had at least one risk allele for the polymorphism rs8050136 and rs9939609. These results together, suggest that PCOS being a multifactorial and multigenic disease is difficult to find a single SNP responsible for the complete phenotype of PCOS, but association studies in different genes can contribute to a better understanding of the different phenotypes, especially in metabolic characteristics of these patients.

A síndrome dos ovários policísticos (PCOS) representa uma das endocrinopatias mais frequentes em mulheres em idade reprodutiva, cujas principais características clínicas são anovulação crônica e manifestações de hiperandrogenismo. Em conjunto com os distúrbios reprodutivos, as pacientes com PCOS apresentam, frequentemente, obesidade e resistência insulínica (RI). Além disso, mulheres com PCOS apresentam maior risco para diabetes tipo 2, dislipidemia e hipertensão arterial e a presença da obesidade pode exacerbar os distúrbios metabólicos associados com a síndrome. A patogênese da PCOS está ligada a maior susceptibilidade ambiental bem como fatores genéticos e esses fatores podem influenciar a apresentação clínica da doença. Variantes genéticas, como polimorfismos de troca de um único nucleotídeo (SNP) vem sendo associadas com alterações metabólicas e clínicas. SNPs no gene TCF7L2 já foram descritos associados ao DM2 2 e RI. Estudos até o presente momento apresentam resultados controversos em relação a variáveis metabólicas e sua associação com os SNPs deste gene em pacientes com PCOS. Outros genes também vem sendo estudados e sabendo que a resistência à insulina e obesidade são característica frequentes de pacientes com a PCOS, o gene FTO surgiu como um possível locus a ser estudado, já que diversos estudos mostram uma associação com esses fatores em outras populações. Até o presente momento estudos mostram dados controversos, possivelmente associados a diferenças entre etnias. Além disso, estudos em uma população latino americana de mulheres com PCOS ainda não foram relatados na literatura. No presente estudo, observamos que os polimorfismos do gene do TCF7L2 rs7903146 e rs11196236 bem como seus haplótipos, não estão associados com a PCOS, mas que a paciente ser portadora de pelo menos um alelo de risco mostra uma variação positiva de 5,87 cm na cintura, 10,7 mg/dl no colesterol total e 10,3mg/dL no LDL-c. Além disso, para verificar a associação do polimorfismo rs7903146 com PCOS realizamos um meta análise, incluindo 1892 mulheres com PCOS e 2695 controles. Os resultados sugerem que o polimorfismo no gene do TCF7L2 não está associado com o risco aumentando de desenvolver PCOS em difefentes etnias (Asiáticas e não Asiáticas). No que se refere ao gene do FTO, os polimorfismos estudados também não foram associados com PCOS, mas os resultados mostram um aumento nos níveis de glicose nas pacientes que possuíam pelo menos um alelo de risco tanto para o polimorfismo rs9939609 quanto para o rs8050136. Estes resultados em conjunto sugerem que a PCOS por ser uma doença multifatorial e multigênica é difícil encontrar um único SNP responsável pelo fenótipo completo da PCOS, mas os estudos de associação em diferentes genes podem contribuir com o melhor entendimento dos diferentes fenótipos, principalmente nas características metabólicas destas pacientes. / The polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive age women, whose main clinical features are chronic anovulation and hyperandrogenism. Together with reproductive disorders, patients with PCOS frequently have obesity and insulin resistance (IR). In addition, women with PCOS have a higher risk for type 2 diabetes, dyslipidemia and hypertension and the presence of obesity may exacerbate the metabolic disturbances associated to the syndrome. The pathogenesis of PCOS is linked to greater environmental susceptibility and genetic factors and these aspects may influence the clinical presentation of the disease. Genetic variants as single nucleotide polymorphisms (SNPs) have been associated to metabolic and clinical changes. SNPs in the TCF7L2 gene have been described in association with DM2 2 and IR. Studies to date are controversial in relation to metabolic variables and their association with the SNPs of this gene in patients with PCOS. Other genes have also been studied and knowing that insulin resistance and obesity are common characteristic in patients with PCOS, the FTO gene has emerged as a possible locus to be studied. Several studies show an association with these factors in other populations. So far studies show controversial data, possibly associated to differences among ethnic groups. In addition, studies in a Latin American women population with PCOS have not been reported in the literature. We have found out that the gene TCF7L2, polymorphisms rs7903146 and rs11196236 and their haplotypes show no differences between genotypes and haplotypes for clinical and metabolic variables. However, for each T (rs7903146) and T (rs11196236) allele added to the haplotypes, a variation of 5.87 cm in waist (P trend=0.01), 10.7 mg/dl in total cholesterol (P trend=0.03), and 10.3 mg/dl in LDL-C (P trend=0.01) was recorded. Also, to verify the association of rs7903146 polymorphism with PCOS we conducted a metaanalysis including 1892 women with PCOS and 2695 controls. The results suggest that polymorphism in the gene TCF7L2 is not associated to the increased risk of developing PCOS in different ethnicities (Asian and non- Asian). As regards the FTO gene, the studied polymorphisms were not associated to PCOS, but the results show an increase in glucose levels in patients who had at least one risk allele for the polymorphism rs8050136 and rs9939609. These results together, suggest that PCOS being a multifactorial and multigenic disease is difficult to find a single SNP responsible for the complete phenotype of PCOS, but association studies in different genes can contribute to a better understanding of the different phenotypes, especially in metabolic characteristics of these patients.

SCA Massa, Östrands massafabrik har två produktionslinjer, fiberlinjen som tillverkar NBSK (blekt barrsulfatmassa) och CTMP-linjen som tillverkar CTMP (kemisk termomekanisk massa). Massaindustrin har trotts övergången från klorblekning till klordioxidblekning fortfarande en påtaglig miljöpåverkan, då tillverkningsprocessen medför både restavfall och förorenade utsläpp. Barrsulfatmassan bleks antingen med ECF (Elemental Chlorine Free) eller TCF (Total Chlorine Free) metoden. Under tillverkningsprocessen av ECF-massa så tillsätts klordioxid som blekkemikalie, vilket leder till att avloppsvattnet som bildas innehåller stora mängder kloratjoner och måste renas innan det släpps ut till recipienten. Under 2014 ansökte SCA om nytt verksamhetstillstånd i Mark- och Miljödomstolen, för att kunna bygga ut Östrands massafabrik och producera upp till 1,1 miljon ton pappersmassa per år. Under 2015 beslutade domstolen om ett nytt tillstånd och för kloratutsläpp sattes ett provisoriskt villkor på 0,5 kg klorat/ ton ECF-massa, som kombinerades med två utredningsnivåer. Utredningsnivå 1 på 0,15 kg klorat/ton ECF-massa och utredningsnivå 2 på 0,05 kg klorat/ton ECF-massa.  Syftet med studien var att undersöka hur det biologiska reningssteget påverkas vid växlingar mellan TCF- och ECF-blekning, och vilka möjligheter det finns att reducera risken för ökade kloratutsläpp. Syftet var också att undersöka om SCA uppfyller det provisoriska villkoret med avseende på utgående mängd klorat per tillverkad ton ECF-massa, och vart SCA ligger i förhållande till utredningsnivå 1 respektive 2. Dygnsmedelvärdesprover har sammanställts och utvärderas för totalt fem månader, från december 2020 till april 2021. Dessa har använts för att undersöka den ingående och utgående mängden klorat från reningen och faktorer som kan påverka reningen. Parametrar som undersökts är pH, temperatur, flöde, syrehalt i kloratsteg A och B och pumpgropen. Stickprover har tagits ur blekeriavloppet, bärarsteg 1A och 1B i samband med växlingar från TCF- till ECF-massa för att undersöka hur kloratsteg A och B påverkas.  Resultatet av undersökningen visade att reningsanläggning har en reduktionsgrad av klorat på ca 89 % i de kloratreducerande stegen, och att reduktionsgraden från bärarsteg 1A till 1B är på ca 31 %. Den största reduktionen av klorat sker i blekerireningen men det sker även en viss reduktion i selektorsteget och de fyra seriekopplade aktivslambassängerna. SCA Östrand ligger som medeltal på ett utsläpp av 0,11 kg klorat/ton ECF-massa. Detta innebär att det provisoriska villkoret på 0,5 (kg klorat/ton ECF-massa) och utredningsnivå 1 på 0,15 (kg klorat/ton ECF-massa) uppnås under den undersökta perioden. SCA Östrand uppfyller inte vid något tillfälle under den undersökta perioden utredningsnivå 2 på 0,05 (kg klorat/ ton ECF- massa). Syrehalten i kloratsteg A och B har en avgörande roll för reduktionen av klorat. Under en tidpunkt uppstod ett handhavande fel på syrgasgivaren och syrehalten reglerades inte till en lägre nivå trotts ECF-massa tillverkning, detta bidrog till högre kloratutsläpp på grund av den minskade reduktionen. I bärarsteg 1A visade det sig att 48 % av mängden klorat i härstammade från pumpgropen. För att minimera risken för ökade kloratutsläpp till recipienten bör inkommande processberört vatten från samlingsavloppet ses över, vilket innebär att kontrollera och minska mängderna klorat till pumpgropen kraftigt. SCA Östrand bör se över breddningen av filtertank 8 som bidrar till ökade mängder klorat till pumpgropen, i samband med klordioxidblekning i blekeriet. För att SCA Östrand ska uppnå utredningskrav 2 måste processinterna åtgärder ses över för att minimera risken att processberört vatten med stora mängder klorat inte passerar kloratsteg A och B i blekerireningen. / SCA Massa, Östrand pulp mill is covered by two production lines, the fiber line producing NBSK and the CTMP line producing CTMP. The pulp industry, despite the transition from chlorine bleaching to chlorine dioxide bleaching, still has a significant environmental impact, as the manufacturing process generates both residual waste and polluted emissions. The sulphate mass is bleached using either the ECF (Elemental Chlorine Free) or TCF (Total Chlorine Free) method. During the production process of the sulphate pulp ECF, chlorine dioxide is added as a bleaching chemical, which results in the wastewater produced containing large amounts of chlorate ions and must be treated before being discharged to the recipient. In 2014, SCA applied to the Land and Environmental Court for a new operating permit to expand the Östrand pulp mill and produce up to 1.1 million tons of pulp. In 2015, the court decided on a new permit and a provisional condition of 0.5 kg chlorate/ton ECF-mass was set for chlorate emissions, which was combined with two investigation levels: investigation level 1 of 0.15 kg chlorate/ton ECF-mass and investigation level 2 of 0.05 kg chlorate/ton ECF-mass.  The aim of the study was to investigate how the biological purification step is affected by changes between TCF and ECF bleaching, and what opportunities there are to reduce the risk of increased chlorate emissions. It also aimed to investigate whether SCA meets the provisional requirement with respect to the output of chlorate per tons of ECF mass produced, and where SCA stands in relation to investigation levels 1 and 2. Daily average samples were compiled and evaluated for a total of five months, from December 2020 to April 2021. These were used to investigate the input and output of chlorate from the purification process and factors that may affect the purification. Parameters investigated include pH, temperature, flow, oxygen supply in chlorate stages A and B and the pump pit. Samples were taken from the bleach drainer, carrier stages 1A and 1B, during changes from TCF to ECF mass to investigate the influence of chlorate stages A and B.  The results of the study showed that the facility of purification has a chlorate reduction degree of 89 % in the chlorate-reducing stages, and that the degree of reduction from carrier step 1A to 1B is about 31 %. The largest reduction of chlorate occurs in the bleaching purification, but there is also some reduction in the selector stage and the four series-connected activated sludge units. SCA Östrand has an average emission of 0.11 kg chlorate/ton ECF-mass. This means that the provisional condition of 0.5 (kg chlorate/ton ECF-mass) and investigation level 1 of 0.15 (kg chlorate/ton ECF-mass) are achieved during the periods under investigation. SCA Östrand does not meet investigation level 2 of 0,05 (kg chlorate/ton ECF-mass) at any time during the period under investigation. The oxygen supply in chlorate steps A and B plays a decisive role in the reduction of chlorate. During one point in time a handling error occurred on the oxygen sensor and the oxygen content was not regulated to a lower level despite ECF- mass production, this error contributed to higher chlorate emissions due to the reduced reduction. To minimize the risk of increased chlorate emissions to the recipient, incoming process treated water from collection drains to carrier stage 1A of the bleach plant should be reviewed. It was found that 48 % of the amount of chlorate in carrier stage 1A originated from the pump pit. In order to minimize the risk of increased chlorate discharge, the amounts of chlorate entering the pump pit must be controlled and greatly minimized. SCA Östrand should review the widening of filter tank 8, which contributes to increased amounts of chlorate to the pump pit, in connection with chlorine dioxide bleaching in the bleaching plant. In order for SCA Östrand to meet investigation requirement 2, in-process measures must be reviewed to minimize the risk that process contaminated water with large amounts of chlorate does not pass through chlorate stages A and B in the facility of purification.

Vid TCF-blekning av pappersmassa är väteperoxid en av huvudkemikalierna. I dagsläget är det svårt att styra blekstegen. Operatörerna måste ta hänsyn till produktionstakt, blekbarheten på massan varierar och fördröjning i trender. PO-bleksteget på Södra Cell Värö har en ungefärlig uppehållstid på 4 timmar och det är först efter så lång tid som man kan se hur en förändring verkligen slår igenom. Överblekning kostar väldigt mycket i kemikalieåtgång och det är därför efterfrågat ett sätt att kunna styra och optimera peroxidblekningssteget. Ett delsteg för detta var att simulera steget experimentellt och från dessa data ta fram en matematisk modell som förutsäger ljusheten. Massa togs ut från fabriken och blektes på labb under kontrollerade förhållanden med satsningar liknande verkliga i fabriken. De parametrar som studerades på labb var temperatur, väteperoxidsats och alkalisats då de påverkar ljusheten mest. En modell för ljushetsökning anpassades sedan till framtagna blekdata. Ekvationer för förbrukning av väteperoxid och hydroxidjoner togs också fram från analyser på blekfiltraten. Med ingående parametrar som startkoncentrationer av kemikalier, temperatur och massakoncentration förutsäger modellen ljusheten väl vid verifiering jämfört med fabrik och verifieringsblekning på labb. Modellen ligger något högre jämfört med fabrik men det var förväntat då förhållanden på labb ger ett renare system. För de parametrar som studerats anpassade sig modellen bra till förändringar och vid verifiering på labb syntes att modellen även svarade med en korrekt ljushet vid förändring i massakoncentration och ingående ljushet i steget. / During TCF-bleaching of pulp, hydrogen peroxide is one of the main chemicals. Today it is difficult to control the bleaching stages. The process operators must consider the production rate, changes in the bleach ability of the pulp and delays of trends in the control system. The PO-bleaching stage at Södra Cell Värö has approximately a retention time of four(4) hours and it is first after that, a result of a change in the process can be seen. Overbleaching is expensive due to high chemical need and therefore it is requested to find a way to control and optimize the peroxide bleaching stage. One way to do this was too simulate the stage experimentally and from those kinetic data accomplish a mathematical model that predicts the brightness increase of the pulp. Pulp from the mill was bleached at the laboratory under controlled conditions and with charges similar to what are used in the plant. The parameters that were studied at lab were temperature, hydrogen peroxide charge and alkali charge as they affect the brightness mostly. A model for brightness increase was adjusted to the achieved bleaching data. Equations for consumption of hydrogen peroxide and hydroxide anions were also developed from analyses of the bleaching filtrates.  From the start parameters, as concentration of the chemicals, temperature and pulp concentration, the model predicts the brightness well according to verification of data from mill and verification bleaching at laboratory. The value from the model is somewhat higher compared to that of the plant but that was expected due to the fact that the conditions at lab give a cleaner system. For those parameters that were studied, the model did adjust well to changes made and according to the verification at lab it was seen that the model also worked for changes in pulp concentration and different brightness at the beginning of the stage.