No description available.

Abstract Cold weather associates with higher cardiovascular morbidity and mortality in various climates. It is also known that exposure to a cold environment instantly activates sympathetic nervous system and elevates blood pressure (BP) in healthy individuals. Hypertension can increase sympathetic reactivity and arterial stiffness, and could therefore exaggerate these cold-related changes. We implemented an experimental study to assess cardiovascular responses to habitual type of cold exposure among subjects with untreated hypertension. We selected a random sample of middle-aged men in the city of Oulu, Finland. The recruitment included home BP measurements. 51 untreated hypertensive men and 32 men without hypertension (controls) underwent 15 minutes whole-body cold exposure (temperature -10°C, wind speed 3m/s, winter clothing, standing). Brachial, central aortic, and continuous BP, as well as electrocardiography (ECG) were measured before (15 min), during (15 min), and after (20 min) the exposure. Skin temperature and thermal sensations were also assessed. The employed exposure increased central and brachial systolic (ca. 25 mmHg) and diastolic (ca. 10 mmHg) BP in both test groups. One fourth of men with mild to moderate hypertension had systolic BP exceeding 200 mmHg while exposed to cold. Small heart rate (HR) reduction was not enough to compensate for the elevated BP, and cardiac workload increased during cold exposure. Cardiac repolarization showed modest arrhythmogenic changes and frequency of ventricular ectopic beats increased slightly in cold conditions. Cold exposure also increased cardiac vagal baroreflex sensitivity in both test groups, whereas an estimate of vascular sympathetic activity increased only among controls. We also found an elevated systolic home BP variability to associate with higher cardiac workload and BP responses to cold. Moderate cold air exposure substantially increased BP but also activated cardiac vagal regulation among untreated hypertensive and non-hypertensive men. The BP level reached in cold conditions was considerably high in those with hypertension, and especially in those with both hypertension and higher home BP variability. These results are important to health care professionals who treat hypertensive patients. The importance of year-round BP control and proper protection from cold should not be underestimated. / Tiivistelmä Kylmään säähän liittyvä verenkiertoelimistön sairauksien paheneminen on havaittu eri ilmastoissa. Tiedetään myös, että terveillä henkilöillä sympaattisen hermoston aktiivisuus ja verenpaine nousevat kylmässä ympäristössä. Kohonnut verenpaine eli hypertensio voi lisätä sympaattista reaktiivisuutta ja valtimojäykkyyttä sekä siten voimistaa verenkiertoelimistön kylmävasteita. Kokeellinen tutkimuksemme arvioi sydämen ja verisuoniston vasteita tavanomaiseen kylmäaltistukseen hoitamatonta hypertensiota sairastavilla henkilöillä. Tutkittavat olivat Oulun väestöstä satunnaisesti valittuja keski-ikäisiä miehiä, joilta määritettiin verenpaine kotimittauksilla. 51 hoitamatonta hypertensionta sairastavaa miestä ja 32 miestä, joilla ei ollut hypertensiota (verrokit), altistettiin 15 minuutin ajan kylmälle (lämpötila -10 °C, tuuli 3 m/s, talvivaatteet, seisten). Verenpainetta mitattiin olkavarresta, epäsuorasti sydämestä ja jatkuvana signaalina ennen altistusta (15 min), sen aikana (15 min) ja jälkeen (20 min). Samalla seurattiin sydämen sähköistä toimintaa, iholämpötiloja ja lämpötuntemuksia. Kylmäaltistus kohotti sekä sydämen että olkavarren ylä- (noin 25 mmHg) ja alapainetta (noin 10 mmHg) molemmissa tutkimusryhmissä. Neljäsosalla lievää tai kohtalaista hypertensiota sairastavista miehistä yläpaine kohosi yli 200 mmHg tasolle. Sykkeen lasku ei riittänyt tasapainottamaan kohonnutta verenpainetta ja sydämen työmäärä nousi. Sydämen rytmihäiriöherkkyys ja vastaavasti kammiolisälyöntien esiintymistiheys olivat myös hieman koholla altistuksen aikana. Kylmäaltistus kasvatti sydämen vagaalista barorefleksiherkkyyttä molemmissa ryhmissä. Verisuonten sympaattinen verenpainevaihtelu kasvoi vain verrokeilla. Sydämen työmäärä ja verenpaine kohosivat kylmässä enemmän heillä, joiden verenpaineen vaihtelu kotona oli korkeampi. Tavanomaista talvipäivää vastaava kylmäaltistus kohotti verenpainetta voimakkaasti, mutta myös aktivoi sydämen suojaavaa säätelyä sekä hoitamatonta hypertensiota sairastavilla että verrokeilla. Kylmässä saavutettu verenpainetaso oli merkittävä heillä, joilla oli hypertensio, ja erityisesti heillä, joilla oli sekä hypertensio että suurempi kotiverenpainevaihtelu. Tämä tutkimustieto on tärkeää hypertensiopotilaille sekä heitä hoitaville terveydenhuollon ammattilaisille. Tulokset korostavat ympärivuotisen verenpainekontrollin ja kylmältä suojautumisen tärkeyttä.

Abstract The objectives of the study were to evaluate factors associated with work ability and musculoskeletal symptoms among food industry workers, to evaluate thermal and neuromuscular responses during repetitive work in the cold and to find out whether cold-induced deterioration in neuromuscular function can be prevented by using additional torso heating or altering work intensity during repetitive work at 4 °C. A questionnaire study (1,117 respondents) and measurements of physical work strain (18 subjects) were performed among workers in food-processing industry. The impact of changes of ambient temperature (16 subjects) and work intensity (8 subjects) on thermal responses and neuromuscular function was evaluated during repetitive work in laboratory conditions. The results from the questionnaire study indicated that self-assessed poor work ability and musculoskeletal symptoms were associated with impaired individual health resources and work-related factors, including higher number of years working in the cold, experience of draught and body cooling at work. Measurements during repetitive work in cold food-processing facilities showed that muscular strain was localized in forearm muscles. Laboratory studies showed that compared with 19 °C, repetitive work at 4 °C increased muscular strain in forearm and upper arm extensors significantly only in men, although the level of muscular strain remained lower and mean skin temperature higher compared with women. Working at 4 °C indicated more continuous activation of the working muscles compared with work at 19 °C. By intermittently increasing the workload at 4 °C the more continuous activation could be counteracted, thus leading to lower strain and fatigue of the working muscles. Additional torso heating did not affect muscular strain of the working muscles at 4 °C. In conclusion, the results indicate a multifactorial feature of work ability and musculoskeletal symptoms among workers in food-processing industry. Gender affects both thermal and neuromuscular responses, which should be considered in the area of work demands and work organization in cold conditions. Altering work intensity could be considered beneficial for reducing muscular strain during repetitive work in cold conditions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Aiming to evaluate the initial growth of bean seedlings, it was done an experiment analyzing the influence of temperature on seed lots of different levels of physiological qualities of two bean varieties (Phaseolus vulgaris L.). The experiment was conducted in climatic chambers in the Didactic and Research Lab of the Departamento de Fitotecnia UFSM where it was used the constant temperatures of 10, 15, 20, 25 and 30ºC, the varieties Valente and Uirapuru and four shares of different physiological qualities, obtained through artificial aging during periods of zero, 12, 24 and 36 hours (41ºC and 100% of air RH). The tests were: germination, first germination count, germination of velocity index, length of hypocotyl and radicle of young plants and dry matter of hypocotyl and radicle. The design used was complete random, with four replications. In the condition of the experiment, variety Uirapuru showed an inferior development compared to Valente in the lowest temperatures for the analyzed variables, while the physiological quality of the seeds interferes in the development of young plants. Low temperatures have affected negatively the germination and elongation of the hypocotyl. / Com o objetivo de avaliar o crescimento inicial de plântulas de feijão, foi realizado um experimento avaliando a influência da temperatura, em lotes com diferentes níveis de qualidades fisiológicas de duas cultivares de feijão (Phaseolus vulgaris L.). O experimento foi conduzido em câmaras climatizadas no Laboratório Didático e de Pesquisas em Sementes do Departamento de Fitotecnia UFSM, onde foram utilizadas as temperaturas constantes de 10, 15, 20, 25 e 30º C, com as cultivares Valente e Uirapuru e quatro lotes de diferentes qualidades fisiológicas, obtidos através de envelhecimento artificial durante períodos de zero, 12, 24 e 36 horas (41º C e 100% de UR do ar). Os testes realizados foram: teste de germinação, primeira contagem de germinação, Índice de Velocidade de Germinação, comprimento de hipocótilo e radícula das plântulas e massa seca de hipocótilo e radícula. O delineamento utilizado foi Inteiramente ao Acaso, com quatro repetições. Para as condições do experimento, a cultivar Uirapuru apresentou desempenho inferior a Valente nas menores temperaturas para as variáveis analisadas, enquanto que a qualidade fisiológica das sementes interfere no desenvolvimento de plântulas. As baixas temperaturas afetam negativamente a germinação e elongação do hipocótilo.

Highway bridges are considered to be one of the most susceptible constituents of transportation networks when they are subjected to severe natural hazards such as earthquakes and environmental exposures like subfreezing temperatures. To facilitate and enhance pre-hazard event mitigation and post-hazard emergency response strategies, probabilistic risk assessment methodologies have attracted increased attention, recently. Seismic fragility assessment is one of the probabilistic techniques which predicts the damage risk of the structure for a given hazard level. While fragility curves can be developed using different methods, such as expert-based, empirical, experimental, analytical, and hybrid, analytical fragility curves are perceived to be the most reliable and least biased technique. Seismic isolation systems are prevalently used in bridge structures to mitigate the damage risk of bridge components against natural hazards. However, the effectiveness of implementing recently emerged isolators such as Stable Unbonded Fiber Reinforced Elastomeric Isolators (SU-FREI) should be examined by developing analytical fragility curves of retrofitted bridges and quantifying the mitigation in the damage probability of different bridge components. In this regard, incorporating the Soil-Structure Interaction (SSI) is critical since the lateral response of bridges relies on the relative stiffness of bridge components, such as columns and isolators and the supporting soil. In addition, all bridge components are exposed to environmental stressors like subfreezing temperature that can alter the seismic response of bridges. In the first phase of this thesis, a seismic fragility assessment is carried out on an existing multi-span continuous reinforced concrete bridge. Two bridge representations are developed to simulate the as-built bridge along with its retrofitted counterpart utilizing SU-FREI. An Incremental Dynamic Analysis (IDA) is conducted using 45 synthetic ground motion records developed for eastern Canada and damage limit states are applied to generate fragility curves and determine the probability of damage to different bridge components. Bridges are analyzed in longitudinal and transverse directions, independently, and component- and system-level fragility curves are developed. In the second phase, the previously generated bridge models are expanded to incorporate the SSI effects by introducing the pile groups under piers and abutments. Several interactions including deck-abutment, abutment-embankment, pile-soil, and pile-soil-pile interactions are considered. A significant challenge in this phase is the accurate simulation of the lateral and vertical behavior of pile groups since all pile groups comprised of closely-spaced vertical and battered piles. A ground motion suite consisting of 45 ground motions has been selected, which reflects the seismicity of the bridge site. IDA is conducted to monitor the seismic performance of the bridge from the elastic linear region up to collapse. Fragility curves, which serve as an important decision-support tool have been developed to identify the potential seismic risk of the bridge. In the third phase, a multi-hazard assessment is carried out by conditioning the previously developed bridge models (i.e. monolithic fixed-base, isolated fixed-base, monolithic with SSI, and isolated with SSI) to a range of room and subfreezing temperatures and applying a seismic excitation, simultaneously. The cold temperature behavior of the constitutive materials of different bridge components, namely, concrete, reinforcing steel, rubber, and the supporting soil are studied and reflected in the bridge models. IDA is performed and damage potential of different bridge components are quantified. In summary, it is demonstrated that SU-FREI is a competing alternative for seismic isolation of bridges by offering potentially less manufacturing time and cost, lower weight, and easier installation which is an attractive feature for accelerated bridge construction applications. In all three phases, it is shown that the bridges which are isolated using SU-FREI have improved seismic performance in comparison with monolithic bridges by exhibiting lower probability of damage to the primary bridge components like columns and pile caps and transferring the damage to less important components such as abutments at which damage does not cause bridge closure. In addition, it is shown that seismic isolation using SU-FREI can effectively mitigate the seismic demand and damage potential of the constitutive components of a bridge supported by weak soil. While occurrence of seismic events along with an environmental stressor such as cold temperature can drastically jeopardize the functionality of a bridge supported by weak soil, it is demonstrated that seismic isolation using SU-FREI can significantly alleviate the probability of damage to bridge components. / Dissertation / Doctor of Philosophy (PhD)

Field studies were conducted in Ontario in 2009 and 2010 to determine the tolerance of winter wheat to herbicide-fungicide tank-mixtures, and the tolerance of winter wheat underseeded red clover to commonly used herbicides applied at three timings. Tank-mixtures including the fungicide tebuconazole caused injury at early and late timings, while mixtures including the herbicide bromoxynil/MCPA were most injurious when applied late in the season. Injury was transient with no yield reductions observed. MCPA/mecoprop/dicamba caused significant yield reductions when applied at normal and late timings, but did not reduce yield when applied early. The herbicides prosulfuron+bromoxynil and pyrasulfotole/bromoxynil were most injurious to underseeded red clover and reduced clover biomass regardless of application timing. Herbicides and herbicide-fungicide tank-mixtures applied early, during cold temperatures do not increase winter wheat or red clover sensitivity; the likelihood of injury is greatest when applications of these products occur late. / Grain Farmers of Ontario; Ontario Ministry of Agriculture, Food, and Rural Affairs; Agriculture Adaptation Council of Canada

Listeria monocytogenes is a foodborne pathogen with a high mortality rate in susceptible populations and is of great public health concern with regard to food safety. The ability to grow at refrigeration temperatures during storage and at low pH levels during food processing has enabled the species to establish and sustain growth on processed food. Some food products particularly at risk of contamination by L. monocytogenes are deli or processed meat products, seafood, processed vegetables, dairy products and other food that do not require heating or reheating before consumption. The aims of this study are therefore to investigate firstly the prevalence rates of the species in high risk food products and a food processing plant in Brisbane. Secondly, to determine whether food isolates are better than environmental isolates at surviving the stress factors in food processing environments, or if their lineage groupings are a better indicator of their survival. Thirdly, to compare the survival of food and environmental isolates under temperature stress in co-cultures. A survey of more than 100 high-risk food products at supermarkets was carried out to investigate the prevalence of L. monocytogenes and other Listeria species in food. Isolates were also obtained from a food processing plant during routine tests. This study has found a low prevalence rate (under 10%) of L. monocytogenes in the processed vegetables and meat products tested. Other products tested included processed and raw seafood and processed fresh fruit. More L. monocytogenes isolates were isolated from the food processing plant (101) than from the food survey (25). Listeria grayi (73 isolates), a non-pathogenic species, was more frequently isolated from the food survey. The characterisation of those isolates has revealed their lineage groupings and REP-PCR profiles, which did not appear to be related to their sources. A selected group of 25 isolates were also serotyped for further identification. A larger number of lineage II isolates (70) were found compared to lineage I isolates (25), and were more common in food than the environments; while some (7) produced inconclusive results in the lineage PCR. The REP-PCR did not separate isolates of different sources, lineages or serotypes. In order to investigate the survival fitness of L. monocytogenes isolates whilst under environmental stress relevant to food safety, ten isolates from the food survey and food processing plant were chosen. Five isolates each from lineages I and II were subjected to temperatures ranging from 4ºC to 30ºC and pH levels from 4.0 to 6.0 for two weeks continuously, with their growth monitored by either optical density or plate counts. It was found that the isolates were most susceptible at the combination of pH 4.0 and 4ºC, where the growth of the isolates was completely inhibited. Again no relationship was observed between the lineage or the sources and the survival fitness of the chosen isolates. Due to the frequency of L. monocytogenes being co-isolated with other Listeria species as well as other food-borne pathogens, the relative competitive fitness of four of the isolates from the survival fitness experiment were compared in co-cultures at 4ºC and 30ºC at pH 7.4 in a small-scale preliminary study. The four isolates from food and environments were grown in broth cultures in pairs with the plate counts performed on antibiotic-supplemented selective TSA agar. The isolates were distinguished on agar supplemented with tetracycline which the isolates had acquired resistance to for this purpose. No significant difference (P>0.05) was observed between the lineages or the sources and the competitive fitness of the isolates in this study. The isolates always produced slightly more colonies in the antibioticresistant form compared to the wildtype form but did not seem to relate to the competitive fitness of the isolates. It would seemed that within the scope of this study, neither the lineage, serotype nor source of the isolates indicated any isolate with a better ability of survival while at low temperatures and low pH levels in pure and mixed cultures. However, other classifying groups such as serotypes, RAPD profiles may reveal possible co-relations, as well as a wider isolate pool. Furthermore, different stress factors could be included as part of an investigation on the survival of L. monocytogenes, as this study focused on food safety during processing.

Listeria monocytogenes is a foodborne pathogen with a high mortality rate in susceptible populations and is of great public health concern with regard to food safety. The ability to grow at refrigeration temperatures during storage and at low pH levels during food processing has enabled the species to establish and sustain growth on processed food. Some food products particularly at risk of contamination by L. monocytogenes are deli or processed meat products, seafood, processed vegetables, dairy products and other food that do not require heating or reheating before consumption. The aims of this study are therefore to investigate firstly the prevalence rates of the species in high risk food products and a food processing plant in Brisbane. Secondly, to determine whether food isolates are better than environmental isolates at surviving the stress factors in food processing environments, or if their lineage groupings are a better indicator of their survival. Thirdly, to compare the survival of food and environmental isolates under temperature stress in co-cultures. A survey of more than 100 high-risk food products at supermarkets was carried out to investigate the prevalence of L. monocytogenes and other Listeria species in food. Isolates were also obtained from a food processing plant during routine tests. This study has found a low prevalence rate (under 10%) of L. monocytogenes in the processed vegetables and meat products tested. Other products tested included processed and raw seafood and processed fresh fruit. More L. monocytogenes isolates were isolated from the food processing plant (101) than from the food survey (25). Listeria grayi (73 isolates), a non-pathogenic species, was more frequently isolated from the food survey. The characterisation of those isolates has revealed their lineage groupings and REP-PCR profiles, which did not appear to be related to their sources. A selected group of 25 isolates were also serotyped for further identification. A larger number of lineage II isolates (70) were found compared to lineage I isolates (25), and were more common in food than the environments; while some (7) produced inconclusive results in the lineage PCR. The REP-PCR did not separate isolates of different sources, lineages or serotypes. In order to investigate the survival fitness of L. monocytogenes isolates whilst under environmental stress relevant to food safety, ten isolates from the food survey and food processing plant were chosen. Five isolates each from lineages I and II were subjected to temperatures ranging from 4ºC to 30ºC and pH levels from 4.0 to 6.0 for two weeks continuously, with their growth monitored by either optical density or plate counts. It was found that the isolates were most susceptible at the combination of pH 4.0 and 4ºC, where the growth of the isolates was completely inhibited. Again no relationship was observed between the lineage or the sources and the survival fitness of the chosen isolates. Due to the frequency of L. monocytogenes being co-isolated with other Listeria species as well as other food-borne pathogens, the relative competitive fitness of four of the isolates from the survival fitness experiment were compared in co-cultures at 4ºC and 30ºC at pH 7.4 in a small-scale preliminary study. The four isolates from food and environments were grown in broth cultures in pairs with the plate counts performed on antibiotic-supplemented selective TSA agar. The isolates were distinguished on agar supplemented with tetracycline which the isolates had acquired resistance to for this purpose. No significant difference (P>0.05) was observed between the lineages or the sources and the competitive fitness of the isolates in this study. The isolates always produced slightly more colonies in the antibioticresistant form compared to the wildtype form but did not seem to relate to the competitive fitness of the isolates. It would seemed that within the scope of this study, neither the lineage, serotype nor source of the isolates indicated any isolate with a better ability of survival while at low temperatures and low pH levels in pure and mixed cultures. However, other classifying groups such as serotypes, RAPD profiles may reveal possible co-relations, as well as a wider isolate pool. Furthermore, different stress factors could be included as part of an investigation on the survival of L. monocytogenes, as this study focused on food safety during processing.

Listeria monocytogenes is a foodborne pathogen with a high mortality rate in susceptible populations and is of great public health concern with regard to food safety. The ability to grow at refrigeration temperatures during storage and at low pH levels during food processing has enabled the species to establish and sustain growth on processed food. Some food products particularly at risk of contamination by L. monocytogenes are deli or processed meat products, seafood, processed vegetables, dairy products and other food that do not require heating or reheating before consumption. The aims of this study are therefore to investigate firstly the prevalence rates of the species in high risk food products and a food processing plant in Brisbane. Secondly, to determine whether food isolates are better than environmental isolates at surviving the stress factors in food processing environments, or if their lineage groupings are a better indicator of their survival. Thirdly, to compare the survival of food and environmental isolates under temperature stress in co-cultures. A survey of more than 100 high-risk food products at supermarkets was carried out to investigate the prevalence of L. monocytogenes and other Listeria species in food. Isolates were also obtained from a food processing plant during routine tests. This study has found a low prevalence rate (under 10%) of L. monocytogenes in the processed vegetables and meat products tested. Other products tested included processed and raw seafood and processed fresh fruit. More L. monocytogenes isolates were isolated from the food processing plant (101) than from the food survey (25). Listeria grayi (73 isolates), a non-pathogenic species, was more frequently isolated from the food survey. The characterisation of those isolates has revealed their lineage groupings and REP-PCR profiles, which did not appear to be related to their sources. A selected group of 25 isolates were also serotyped for further identification. A larger number of lineage II isolates (70) were found compared to lineage I isolates (25), and were more common in food than the environments; while some (7) produced inconclusive results in the lineage PCR. The REP-PCR did not separate isolates of different sources, lineages or serotypes. In order to investigate the survival fitness of L. monocytogenes isolates whilst under environmental stress relevant to food safety, ten isolates from the food survey and food processing plant were chosen. Five isolates each from lineages I and II were subjected to temperatures ranging from 4ºC to 30ºC and pH levels from 4.0 to 6.0 for two weeks continuously, with their growth monitored by either optical density or plate counts. It was found that the isolates were most susceptible at the combination of pH 4.0 and 4ºC, where the growth of the isolates was completely inhibited. Again no relationship was observed between the lineage or the sources and the survival fitness of the chosen isolates. Due to the frequency of L. monocytogenes being co-isolated with other Listeria species as well as other food-borne pathogens, the relative competitive fitness of four of the isolates from the survival fitness experiment were compared in co-cultures at 4ºC and 30ºC at pH 7.4 in a small-scale preliminary study. The four isolates from food and environments were grown in broth cultures in pairs with the plate counts performed on antibiotic-supplemented selective TSA agar. The isolates were distinguished on agar supplemented with tetracycline which the isolates had acquired resistance to for this purpose. No significant difference (P>0.05) was observed between the lineages or the sources and the competitive fitness of the isolates in this study. The isolates always produced slightly more colonies in the antibioticresistant form compared to the wildtype form but did not seem to relate to the competitive fitness of the isolates. It would seemed that within the scope of this study, neither the lineage, serotype nor source of the isolates indicated any isolate with a better ability of survival while at low temperatures and low pH levels in pure and mixed cultures. However, other classifying groups such as serotypes, RAPD profiles may reveal possible co-relations, as well as a wider isolate pool. Furthermore, different stress factors could be included as part of an investigation on the survival of L. monocytogenes, as this study focused on food safety during processing.

The project undertaken in this thesis was performed at MittSverige Vatten och Avfall (MSVA) in cooperation with the Swedish Environmental Research Institute (IVL). The effect of temperature on nitrogen removal using moving bed biofilm reactor (MBBR) was controlled using two separate lines by investigating the influence of temperature on nitrification, pre-denitrification, and post- denitrification in a pilot plant scale. By monitoring the process using chemical analysis, batch tests and online systems, it was possible to observe the changes occurring in the different reactors along with different parameter set-ups and react to the undesirable changes in the system. Due to some limitations, the master's thesis couldn’t fully answer the objective of the study. Nonetheless, the processes were investigated and evaluated to better understand the possibilities and limitations of nitrogen removal with MBBR with treating cold wastewater. During the study period, the inflow coming to the pilot plant, recirculation flow, external carbon dosing, set points of dissolved oxygen and temperature values were controlled. By manipulating these different parameters, it was possible to observe their impacts on the processes. The inflow was variable between 0.42 and 0.67 m3/h, recirculation flow was set to 1.2 m3/h at the beginning then changed to function same as the inflow after being reduced to 0.84 m3/h in between. DO level was variable throughout the entire study period with an average concentration of 4.2mg/l in line 1 and 4.43 mg/l in line2 in all the aerated zones for each line. Temperature of incoming water varied between 5.94 and 9.3 oC with an average temperature of 7.73 oC while the average temperature of the water in the system in line 1 was 13.3 oC and 12.62 oC in line 2. During the 5 months study period, the system achieved an average total nitrogen removal efficiency of 46% in line 1 and 60% in line 2. / Projektet i detta examensarbete utfördes vid MittSverige Vatten och Avfall (MSVA) i samarbete med Svenska Miljöinstitutet (IVL). Effekten av temperatur på kväveborttagning med användning av biofilmreaktorer med rörliga bärare (MBBR, eng. för Moving Bed Biofilm Reactor) kontrollerades genom att undersöka temperaturens inverkan på nitrifikation, pre-denitrifikation och post- denitrifikation i två separata linjer i en pilotanläggningsskala. Genom att övervaka processen med hjälp av kemiska analyser, batchtester och online-system, var det möjligt att observera de förändringar som sker i de olika reaktorerna tillsammans med olika parameteruppsättningar och reagera på de oönskade förändringarna i systemet. På grund av vissa begränsningar kunde masteruppsatsen inte helt svara på syftet med studien. Ändå har processerna undersökts och utvärderats för att bättre förstå möjligheterna och begränsningarna av kväverening med MBBR vid rening av kallt avloppsvatten. Under studieperioden kontrollerades inflödet till pilotanläggningen, recirkulationsflöde, extern koldosering, börvärden för löst syre och temperaturvärden. Genom att ändra dessa olika parametrar var det möjligt att observera deras inverkan på processerna. Inflödet var variabelt mellan 0,42 och 0,67 m3 /h, recirkulationsflödet sattes till 1,2 m3/h i början och ändrades sedan till att fungera som inflödet efter att ha reducerats till 0,84 m3 /h däremellan. DO- nivån var variabel under hela studieperioden med en genomsnittlig koncentration på 4,2 mg/l i linje 1 och 4,4 mg/l i linje 2 i alla luftade zoner för varje linje. Temperaturen på inkommande vatten varierade mellan 5,9 och 9,3 oC med en medeltemperatur på 7,7 oC medan medeltemperaturen på vattnet i systemet i linje 1 var 13,3 oC och 12,6 oC i linje 2. Under den 5 månader långa studieperioden uppnådde systemet en genomsnittlig total kvävereduktionseffektivitet på 46 % i linje 1 och 60 % i linje 2.