Ett av världens största miljöproblem är plastnedskräpning. På många platser kan spår av mänsklig närvaro ses i form av skräp av plast. År 2011 tillverkades det 280 miljoner ton plast, det motsvarar ungefär 28 000 Eiffeltorn. I Sverige förbrukades år 2010 ungefär 880 000 ton plast. I Asien produceras ungefär 50 % av all världens plast och Kina står för cirka hälften av detta. Nordamerika och Europa står för cirka 40 % av världens plastproduktion. Resterande produktion av plast är fördelat på Afrika och Sydamerika. Kommersiell plast är uppbyggd av små enheter kallade polymerer. Polymerer är i sin tur uppbyggda av ännu mindre enheter som kallas monomerer. Dessa monomerer är i dagsläget framställda av petroleum (råolja/mineralolja). Ungefär 4 % av världens oljekonsumtion går åt som råvara till att producera plast och lika mycket olja används som bränsle i tillverkningsprocessen. Begreppet bioplast är en hel familj av material som är biologiskt nedbrytbar, biobaserade eller bådadera. Det är dock inte en självklarhet att bioplaster besitter båda egenskaperna. PHA-plast är biobaserad och biologisk nedbrytbar, vilket är anledningen till att den står i fokus under detta examensarbete. För produktion av PHA-plast används en trestegsprocess, vilket innefattar ett fermenteringssteg, ett selektionssteg och ett ackumuleringssteg. Sist sker en extraktion för att frigöra PHA- plasten från det övriga organiska materialet. Syftet med det här examensarbetet är att med hjälp av framställning av bioplast främja miljön, vilket en anläggning som producerar bioplast skulle göra eftersom en del av den fossiloljebaserade plasten skulle kunna bytas ut mot bioplasten PHA. Större framställningsmöjligheter av bioplast i Värmland skulle medföra ett ökat intresse av en produktionsanläggning. Målet är att inventera olika industrier runt om i Värmland, i första hand matindustrier och skogsindustrier, och utreda deras processavloppsvattens potential att producera VFA. I detta examensarbete har fermenteringsförsök genomförts satsvis på processavloppsvatten från OLW, Barilla (Wasa), Skoghall, Gruvön och Rottneros. Försöken visar deras potential att producera VFA. Experimenten utfördes med ett konstant pH på 6 och varierande uppehållstid. Resultaten visade att OLW och Barilla har bäst potential till VFA-produktion med 4500 mg/l respektive 1610 mg/l. Spädning av OLWs och Barillas processavloppsvatten visade sig vara en gynnsam åtgärd, då VFA-produktionen ökade snabbare i jämförelse med de tester som utfördes vid icke-spädning. Dock erhölls inte lika stor totalmängd av VFA. Det är dock bättre att producera en större mängd VFA och på så vis låta processen ta längre tid. Vid fortsatta experiment rekommenderas att göra ytterligare försök på OLW och Barillas processavloppsvatten då de visade bäst potential till VFA-produktion. / One of the biggest environmental problems is the plastic littering. In many places traces of human presence is seen in the form of plastic littering. In the year 2011, 280 million tons of plastic was produced, which represents about 28 000 Eiffel Towers. In Sweden, about 880 000 tons of plastic a year is consumed, according to figures from 2010. Approximately 50 % of all the world's plastics are produced In Asia and China accounts for about half of it. North America and Europe account for about 40% of the world's plastic production. The remaining production is distributed between Africa and South America. Commercial plastic is made from small units called polymers. A polymer consists of smaller units called monomers. In present, these monomers are produced out of petroleum (crude oil/ mineral oil). Approximately 4% of the world’s oil consumption is spent as raw material to produce plastic and the same amount of oil is used as fuel in the plastic production process. The term bio-plastic is used for a family of materials which are biodegradable, bio- based or both. However, it is not given that bioplastics do possess both properties. PHA plastics are both bio based and biodegradable, which is why it is the focus for this thesis. Production of PHA plastic is a three-step process comprising a fermentation step, a selection step, and an accumulation stage. Finally, there is an extraction to release the PHA plastic from the organic material. The aim of this thesis is to aid the production of bioplastics in order to lessen the environmental load of plastics. The more bioplastic that can be produced, the greater the interest of a bioplastic-producing plant in Värmland. The goal is to make an inventory of industries around Värmland, primarily food industries and forest industries, and to quantify the potential of their process wastewaters to produce VFA. In this thesis, fermentation experiments conducted batch-wise was performed with process wastewater from OLW, Barilla (Wasa), Skoghall, Gruvön and Rottneros. The experiments showed the wastewaters potential to produce VFA. The experiments were performed with a constant pH of 6 and with varying residence time. The results showed that OLW and Barilla has the highest potential for VFA production with 4500 mg/l and 1610 mg/l, respectively. Dilution of OLWs and Barillas process water turned out to be favorable, as the VFA production increased rapidly in comparison with those tests that were conducted under non-dilution. The total production of VFA, however, was not as high. In further experiments, it is recommended to make another attempt at the OLWs and Barillas process wastewater since they showed the best potential for VFA production.

The purpose of this research was to investigate the relationship between the oxidation-reduction potential (ORP) measurement and volatile fatty acid (VFA) production in the acid-phase anaerobic digestion process under different conditions of temperature and residence time. Two identical anaerobic digesters were operated while VFAs, SCOD, VSS, alkalinity, ORP and pH were measured. In digester 1, VFA production of 5,556 mg/L was generated with an ORP of -315 mv at a 10 day SRT; while 5,400 mg/L of VFA with an ORP of -389 mv was recorded in digester 2. The SRT was adjusted at 5, 8, 10, 12 and 15 days and the optimum SRT was 10 days in both digesters. The results of this study indicate there were no tight relationship between VFA production and ORP values, thus ORP by itself is not a good predictor of the amount of VFAs generated. However, ORP combined with temperature had good linear relationship with VFA production. An ORP range of -315 to -390 mv was desirable for maximizing VFA production in both anaerobic digesters. Different temperatures (14, 29 and 37 ℃) were trialed and the results indicate that the conditions at 29 ℃ and 37 ℃ were not significantly different in terms of VFA production, however, less VFAs were generated at the lowest temperature of 14 ℃.

Precision livestock farming is gaining popularity in both the research and production setting. Despite this, current technologies are limited in the ability to explore the rumen environment. The overall goal of this work was to explore sensing technologies that could enable shifts in management to maximize productivity in ruminant production systems. In the first study, we assessed the use of existing sensor technologies to monitor ruminal volatile fatty acid (VFA) concentrations using pH sensing. Four ruminally cannulated Holstein cows at maintenance were included in a Latin Square Design. Treatments consisted of a) chopped grass hay, b) 85% chopped grass hay and 15% cracked corn and soybean meal, c) 70% chopped grass hay and 30% cracked corn and soybean meal, and d) 55% chopped grass hay and 45% cracked corn and soybean meal. Prior to receiving treatment diets, cows were individually housed and underwent a fasting period of up to 24 hours. During each period, cows were allowed access to treatment diets from 0600 to 0800 hours, and rumen fluid samples were collected hourly for twelve hours beginning at feed delivery. A bench pH meter was used to obtain rumen fluid pH levels at sampling times. Concentrations of individual VFA and branch-chain VFA were analyzed statistically using two linear mixed effects models. In one model type, VFA were estimated through fixed effects terms for treatment, time, and the treatment by time interaction. For comparison, the other model estimated VFA concentrations using linear and quadratic effects for the sensed pH data. Both models leveraged random effects for animal and period. Models utilizing diet data and time showed better performance in estimating VFA concentrations compared to models leveraging pH data, indicating minimal predictive capacity was identified for the pH sensing. The second study explored opportunities to track ruminal VFA concentrations based on aqueous sensing of ruminal CO2, temperature, and conductivity across four diets differing in energy and protein supply. Four ruminally cannulated Holstein cows at maintenance were included in a Latin Square Design. Treatments consisted of a) chopped grass hay (9.07 kg), b) chopped grass hay (9.07 kg) plus cracked corn (4.08 kg), c) chopped grass hay (9.07 kg) plus soybean meal (2.13 kg), and d) chopped grass hay (9.07 kg) plus corn (2.38 kg) and soybean meal (0.83 kg). Prior to receiving treatment diets, cows were individually housed and underwent a fasting period of up to 24 hours. During each period, cows were allowed access to treatment diets from 0600 to 0800 hours, and rumen fluid samples were collected hourly for twelve hours beginning at feed delivery. A CO2 electrode and conductivity probe were placed in the rumen of each cow to investigate the relationship between aqueous ruminal CO2, temperature, and conductivity, with sensor measurements recorded every three minutes beginning at 0545h. Concentrations of individual VFA were analyzed statistically using a linear mixed effects model with fixed effect for treatment and sensing data and random effects for animal and period. Single-point-in-time modeling of VFA concentrations from sensor data demonstrated comparable or improved results in terms of error variance and Concordance Correlation Coefficient (CCC) compared to models using diet and time variables. Incorporating time-lagged sensor variables further improved the predictive capacity and reduced residual error variance. Adding diet descriptions to the lagged sensor data did not enhance the ability to explain variability in VFA concentrations. These models indicate VFA concentrations can be well characterized from aqueous, ruminal sensing of CO2, temperature, and conductivity, in a manner apparently independent of and robust across diets. / Master of Science / Cattle feeding practices have shifted over the past several decades to enhance efficiency and better meet increasing energy requirements associated with greater genetic capacity for meat and milk production. In practice, this shift has relied on greater use of high-energy and nutrient-dense concentrate feeds over fiber-rich forages. The synthesis of volatile fatty acid (VFA), a primary product of microbial fermentation which plays a crucial role in supplying up to 70% of the ruminant's energy, is driven primarily by diet characteristics. Dietary nutrient supplies have a reciprocal relationship with the ruminal microbial community, shifting the profile of fermentation, and subsequently influencing the health and efficiency of the host. As such, there has been a long history of investigation of VFA profiles produced from various diets as a strategy to better understand the complexities driving the relationships linking diet, host, microbial community, and fermentation outcomes. Although there are existing rumen monitoring technologies, there are none currently capable of monitoring VFA concentrations in the rumen. The overall goal of this work was to explore the ability of existing sensor technologies to monitor ruminal VFA concentrations. The first study sought to explore the use of pH sensing to estimate ruminal VFA concentrations. Four ruminally cannulated Holstein cows were fed four diets differing in forage to concentrate ratios using grass hay, cracked corn, and soybean meal. Sampling periods for each animal lasted four days, with cows returning to cool season grass pasture between sampling periods. Cows were fasted for up to 24 hours prior to receiving treatment diets, and sampling periods began at 0600 with feed delivery, and rumen fluid samples were collected hourly for 12 hours. Rumen pH was determined at time of sampling using a bench pH meter. Concentrations of individual VFA and branch-chain VFA were analyzed statistically using two linear mixed effects models. In one model type, VFA were estimated through fixed effects terms for treatment, time, and the treatment by time interaction. For comparison, the other model estimated VFA concentrations using linear and quadratic effects for the sensed pH data. Both models leveraged random effects for animal and period. Models leveraging pH data held greater error rates when compared with models including diet and time data, indicating pH alone is an insufficient method of estimating ruminal VFA concentrations. The second study targeted sensing of aqueous ruminal CO2, temperature, and conductivity as indicators of VFA concentrations. Four ruminally cannulated Holstein cows were fed four diets differing in forage to concentrate ratios using grass hay and top dresses of cracked corn and soybean meal. Sampling periods for each animal lasted four days, with cows returning to cool season grass pasture between sampling periods. Cows were fasted for up to 24 hours prior to receiving treatment diets, and sampling periods began at 0600 with feed delivery, and rumen fluid samples were collected hourly for 12 hours. Conductivity and CO2 probes were placed in the rumen prior to feed delivery, and measurements were recorded every three minutes. Concentrations of individual VFA were analyzed statistically using a linear mixed effects model with fixed effect for treatment and sensing data and random effects for animal and period. Models leveraging single-time-point measurements of aqueous ruminal CO2, temperature, and conductivity had similar, and in many cases, improved residual errors when compared with models using diet and time information. Incorporating time-lagged sensor variables further improved the predictive capacity and reduced residual error variance, and adding diet descriptions to the lagged sensor data did not enhance the ability to explain variability in VFA concentrations. The results of the two studies completed indicate that sensing of indicators of ruminal fermentation, like aqueous CO2, temperature, and to a lesser extent conductivity, is a sufficient method of determining ruminal VFA concentrations.

The community college mission is to provide open access to higher education for all students. For that reason, accountability measures have focused primarily on student access to their institutions. However, in recent years there was a shift to include student progress and outcomes, in addition to access, as measures of institutional effectiveness. With this shift came concerns by community college leadership on a national level that they were being held accountable with measures that were inappropriate for this sector of higher education. As a result, the Voluntary Framework of Accountability (VFA) was created. This framework is unique in that it was designed for and by community colleges and is currently being piloted on a national basis by the American Association of Community Colleges at approximately 100 locations. This qualitative research case study, based upon grounded theory, chronicles the participation process of the Community College of Allegheny County (CCAC) in the development and piloting of accountability metrics using the VFA model to measure student progress and outcomes and the resultant impact on policy and practice at the CCAC. In my research, I found a number of factors shaping the implementation of the VFA pilot. The decision of the CCAC to participate in the development and pilot project of the VFA can be traced back to the increased pressure of accountability on the institution and the leadership of the current president and his philosophy about data informed decision-making. Other findings that influenced the implementation of the VFA included the limitations of the pre-VFA metric definitions and measurements that were being used to account for student progress and outcomes. In my treatise I describe the implementation issues, including the challenges and benefits of using the VFA accountability model, and then examine how it has impacted organizational policy and practices. / text

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Bakgrund: Små-medelstora-företag (SME) har en viktig roll i dagens samhälle. SMEs står idag för en stor del av arbetsgivarsegmentet samt för en stor del av den ekonomiska utveckling som sker i Europa. Inom tillverkningsindustrin är en av utmaningarna att säkerställa robusta processer med hög kvalitet. För SMEs innebär det kontinuerlig uppföljning av de interna samt externa processerna för att hela tiden försäkra sig om att verksamheten följer uppsatta ramar, vilket generellt kan vara svårt eftersom tillgängliga resurser är begränsade. Andra utmaningar som tillverkande företag står inför är långa ledtider, högt antal produkter i arbete (PIA), lagerbildningar mellan processer och kassationer. En av de viktigaste egenskaperna för tillverkande SMEs konkurranskraftighet är företagets förmåga att leverera i tid.   Syfte: Syftet är att undersöka leveranssäkerheten i ett SME inom tillverkningsindustrin, med tillhörande frågeställning: Hur kan Lean-verktyg appliceras för att minimera PIA och ledtider samt bibehålla hög leveranssäkerhet?   Ansats: För att undersöka leveranssäkerheten i ett SME inom tillverkningsindustrin valdes ett företag med flera produktionsanläggningar och globala kunder med höga krav att leverera i tid till kunden. Värdeflödesanalys (VFA) tillämpades för att utforska hur produktionssystemet i företaget presterade, ge insikt till hur företaget arbetar med leveranssäkerhet och om leveranssäkerheten kan ökas genom implementering av identifierade förbättringsmöjligheter. Semistrukturerade intervjuer utfördes för att samla data om hur fallföretaget och dess personal arbetar och säkerhetsställer att produkter levereras i tid. För produktions- och leveransrelaterad data utfördes observationer på en av fallföretagets produktionsanläggningar för en högvolymprodukt. Insamlad data från observationer, dokumentation och intervjuer bearbetades med Lean-verktyg och metoder och jämfördes sedan mot den teoretiska referensramen genom mönsterpassning som analysmetod för att uppnå studiens syfte och ge svar på studiens frågeställning.   Resultat: Genom att analysera fallföretagets produktionssystem har faktorer som kan påverka leveranssäkerheten undersökts med hjälp av VFA och förbättringsområden identifierats. Ett teoretiskt förslag har tagits fram där en balansering av befintligt produktionssystem utförts. I förslaget har både ledtider och PIA reducerats. Genom implementering av det teoretiska förslaget kan fallföretaget uppnå en reducering av PIA och ledtider samt bibehålla sin höga leveranssäkerhet. Vidare skapar det teoretiska förslaget möjligheter för fallföretaget att ha en flexiblare produktion eftersom överskottskapacitet finns i produktionssystemet för produktion av andra produkter.   Originalitet/värde: Studien ger insikt i hur ett SME företag i tillverkningsindustrin arbetar med leveranssäkerhet och hur högre leveranssäkerhet kan erhållas genom applicering av Lean-verktyg.

Företaget Boliden är världens främsta producent av zink och ledande i Europa medproduktion av koppar och nickel.För att nå malmen under jord drivs ramper och orter genom borrning, sprängningoch bergförstärkning. Dessa arbetsmoment kräver att stora mängder vatten tillförs,bland annat för att binda dammet som uppstår vid arbetsmomenten och även för attkyla maskinerna. Vattnet som är i omlopp i gruvan hanteras av länspumpar, sompumpar vattnet runt i gruvan eller upp till reningsverk.Bolidens gruva i Renström har länge haft problem med pumparna under jord, bådegällande den låga tillgängligheten och höga reparationskostnader. Syftet med dennarapport är att analysera och utvärdera möjligheterna att minska de kostnader somfinns kopplat till trasiga pumpar. Det slutgiltiga målet är att utvärdera och gekonkreta rekommendationer på hur Boliden Renström kan hantera de trasigapumparna i framtiden. De avgränsningar som fastställts är att enbart ganskaprocessflödet från när trasiga pumpar anländer till nivå 1125 tills de är tillbakareparerade på nivå 1125. Vissa ekonomiska faktorer som är svårbedömda kommeratt baseras på grova beräkningar och antaganden.Med hjälp av observationer och intervjuer ritades ett värdeflöde över nuläget.Värdeflödesanalysen och Lean’s teorier om slöseri jämfördes för att hitta onödigamoment i nuläget. Förbättringsåtgärder togs fram för att eliminera det slöseri somfanns. Dessa förbättringsåtgärder är; Minska antalet pumpar i flödet Ställa högre reparationsvillkor på den interna reparatören Hantera pumpar styckevis istället för stora partistorlekar Ändra beställningsrutinerna i Maximo Vidare analyserades tre olika framtida tillstånd för pumpreparationerna; reparerabåde internt och externt, endast reparera internt eller endast reparera externt. Dessatre framtida tillstånd analyserades med SWOT-analyser för att se dess fördelar och nackdelar.Rekommendationen som lämnas är att reparera alla pumpar internt, då det är detbilligaste alternativet samt har kortare ledtid än nuläget. Enligt SWOT-analysenframkom några svagheter och hot, dessa bör Boliden Renström se över innan någrabeslut tas. En avslutande rekommendation är att se över om det finns möjlighet attendast jobba med en serie av pumparna och dess modeller, anpassat efterverksamhetens behov.De framtida studier som lämnas till företaget är att se över om det är möjligt attordna en gemensam verkstad för Bolidenområdets pumpar. Vidare skulle det ävenvara intressant att se vad resultatet blir om pumpstyrning och fasföljdstyrninginstalleras i pumparna.

Small ruminant species are utilized for their diverse products including meat, dairy products, and wool. Effective and humane management are essential to maintain high production rates and comfortable animals. To attain this objective, managers needs to have an extensive knowledge of husbandry techniques, understanding of physiological processes, and familiarity with nutritional requirements. We examined the effects of varying feed components on two different ruminal species. In Chapter 1, we conducted a study to evaluate"¯the effects"¯of a low metabolizable energy (LME) and high metabolizable energy (HME) diet on twenty-two Friesian/Lacuane"¯cross ewes and lamb nutritional status."¯Effects on milk production during early lactation stages"¯and the growth of the neonatal lambs were also investigated. We anticipate energy levels will have an effect on milk production and lamb growth. Our results indicate that ewes on the LME diet produced more milk with higher concentrations of fat though this group maintained lower body condition. We concluded that neither the HME nor the LME diet met the needs of the sheep due to the shift in nutrient partitioning towards milk production rather than allocating nutrients to maintaining both body condition and milk production. Limited energy requirements are further evidenced by the decline in back fat (BF) for both the HME and LME groups for the duration of the study. We determined the degradation parameters of grass hay supplemented with soybean meal (SBM) and the effects of SBM on compartment 1 (C1) ammonia and volatile fatty acid (VFA) concentrations in alpacas. Our findings show that the degradation rate was not different for dry matter (DM), but it was for crude protein (CP) (P<0.05). With this data it can be concluded that SBM can be a CP supplement when the diet is insufficient to improve microbial yield. It should be noted that care should be taken to avoid causing a protein-energy imbalance. The results of these two studies indicate shifts in nutrients availability and changes in feeding strategies can affect both the health of the animal and their subsequent offspring.

Short-term sludge fermentation was explored as a means of solubilizing phosphorus from different types of undigested sludge to facilitate nutrient recovery and generate volatile fatty acids (VFA) for enhanced nutrient removal. Phosphorus solubilization and VFA production was compared from the fermentation of primary sludge (PS), waste activated sludge (WAS), and from co-fermenting primary and waste activated sludge from wastewater treatment plants that do not practice biological nutrient removal. Co-fermented sludge resulted in the best combination of nutrient release and VFA production compared to separate fermentation of PS and WAS. After 4 days of fermentation, co-fermented sludge contained 48% of TP as dissolved phosphorus, and produced 1624 mg l-1 of VFA-COD which corresponds to a VFA-COD production rate of 0.139 mg mg-1 VS. In terms of total sludge management, co-fermentation resulted in greater overall VFA production and phosphorus solubilization than individual sludge fermentation.

High-rate anaerobic degradation of soluble organic pollutants is becoming very popular, particularly for carbohydrate-based industrial wastewaters. Despite the successes achieved, there are significant limitations in the application of this technology to more complex wastewaters. These are defined as containing other organic compounds such as particulate and soluble proteins and fats, and originate from abattoirs (slaughterhouses), meat and food processing and similar industries. Complex wastewater is often difficult to degrade and components such as solids and fats have slow degradation kinetics and can diminish process performance. Also, the growth of granular sludge, which is critical for optimal performance in upflow reactors, is slow and granule properties such as shear strength and settling velocity are poorer. This is reflected in a lower treatment efficiency of 50%-60% in systems treating complex wastewater compared with efficiencies of 85%-95% in carbohydrate fed treatment systems. This thesis examines specific aspects in the treatment of complex (proteinaceous) wastewater in high rate upflow anaerobic treatment plants and the influences of different conversion processes and microbial characteristics on design and operation. The research problem was approached in two ways: The macroscopic conversion processes were examined by investigating and modelling a two-stage full-scale high rate hybrid reactor in Spearwood, Western Australia, designed and operated by ESI Ltd. This allowed localisation of the key conversion process; specifically hydrolysis of solids, which was found to occur mainly within the methanogenic reactor. Degradation of soluble proteins was rapid and all proteins were fully acidified in the acidogenic (first) stage even at very low retention times. Because of the rapid protein degradation rates, partial acidification, which is often a strategy to improve granulation rates, is incompatible with pH, flow and concentration equalisation. The influence of a protein feed on granulation compared with a carbohydrate feed was examined by sampling granules from the above reactor, as well as two full scale brewery fed reactors and a full scale reactor fed fruit and vegetable cannery wastewater. The cannery fed granules had the highest shear strength and settling characteristics while the protein fed granules had low strength and density , low settling velocity and a comparatively wide size distribution. Both brewery fed granules had very similar and suitable properties. Molecular studies using fluorescent in-situ hybridisation (FISH) probing and microscopy indicated that the granules from the complex (protein) wastewater fed reactor had limited structural characteristics , possibly due to limited reaction rates (as opposed to diffusion rates). Granules from the cannery reactor and both brewery reactors had structures that appeared to be the result of diffusion limitations. Therefore, the critical operational constraints when treating complex wastewater are the particulate biomass and particulate substrate. Awareness of process status could be increased by monitoring of biological and substrate solid inventory in the methanogenic reactor. The model developed in this thesis can greatly assist this. Complications due to particulate substrate and poor granule properties may be intrinsic to complex feeds. These constraints are probably best addressed by design of a methanogenic reactor specifically for complex wastewater. The design should attempt to separate substrate hydrolysis, minimise shear on the granules and retain solids.