Water Reuse in Paper Mills - Measurements and Control Problems in Biological Treatment

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En studie i historiebruk : Analys av reseguider från Estniska SSR

The use of history is the concept of people using and analyzing history in the society for various purposes. Study in this area has largely emerged because there are many different reasons for people and societies to be interested in history. To investigate the use of history, a historical material needs to be present in some form. With this study, I intend to show how older tourist guidebooks can provide such materials of study and therefore I use travel guidebooks about Tallinn released under the USSR (Estonian SSR) between the years 1960 to 1990. The analysis is based on Klas-Göran Karlsson's (Professor of History) typology of seven different uses of history: scientific, existential, moral, ideological, political, educational, non-use of history and a commercial use of history. This paper has highlighted several different historical dimensions in travel guides and reasons why they can be analyzed. Results of this study show that the travel guides can act as a medium for existential orientation and that they can function as a communicational, educational and an interest raising tools. They can also develop a critical approach towards historical events and help to "sell" history through various commercial products. Thus, tourist guidebooks can be used and analyzed more systematically by professionals, interested individuals or a group who feel the need, desire or interest in the way history can be used in their practices. Historiebruk handlar om hur människor använder och analyserar (brukar) historia i samhället för olika syften. Studieområdet har till stor del vuxit fram eftersom det finns många olika skäl att intressera sig för historia. För att undersöka historiebruk behövs ett studieobjekt som på något sätt tar upp historia. Med denna uppsats ämnar jag undersöka hur äldre reseguider kan utgöra sådana studieobjekt och därför kommer reseguider om Tallinn från Estniska SSR utgivna mellan 1960 till 1990 användas i historiebruksundersökningen. Analysen utgår från historieprofessorn Klas-Göran Karlssons typologi med sju olika historiebruk – ett vetenskapligt, ett existentiellt, ett moraliskt, ett ideologiskt, ett politiskt-pedagogiskt, ett icke- bruk av historia och ett kommersiellt. Undersökningen har belyst flera olika historiska dimensioner i reseguiderna och motiv till varför de kan analyseras. Resultatet av undersökningen visar på fyra punkter. Den första är att reseguiderna kan agera medium vid existentiell orientering. Den andra att de kan fungera som kommunikations-, kunskaps- och intresseprocess. Den tredje punkten är att de kan utveckla ett kritiskt förhållningssätt och fjärde punkten handlar om att reseguiderna kan vara motiv för att “sälja” historia vid utvecklingar av olika kommersiella produkter inom exempelvis turismen. Likaså att reseguiderna kan nyttjas och analyseras av antigen en individ eller grupp som känner behov, önskan eller intresse

En studie i historiebruk : Analys av reseguider från Estniska SSR

The use of history is the concept of people using and analyzing history in the society for various purposes. Study in this area has largely emerged because there are many different reasons for people and societies to be interested in history. To investigate the use of history, a historical material needs to be present in some form. With this study, I intend to show how older tourist guidebooks can provide such materials of study and therefore I use travel guidebooks about Tallinn released under the USSR (Estonian SSR) between the years 1960 to 1990. The analysis is based on Klas-Göran Karlsson's (Professor of History) typology of seven different uses of history: scientific, existential, moral, ideological, political, educational, non-use of history and a commercial use of history. This paper has highlighted several different historical dimensions in travel guides and reasons why they can be analyzed. Results of this study show that the travel guides can act as a medium for existential orientation and that they can function as a communicational, educational and an interest raising tools. They can also develop a critical approach towards historical events and help to "sell" history through various commercial products. Thus, tourist guidebooks can be used and analyzed more systematically by professionals, interested individuals or a group who feel the need, desire or interest in the way history can be used in their practices. Historiebruk handlar om hur människor använder och analyserar (brukar) historia i samhället för olika syften. Studieområdet har till stor del vuxit fram eftersom det finns många olika skäl att intressera sig för historia. För att undersöka historiebruk behövs ett studieobjekt som på något sätt tar upp historia. Med denna uppsats ämnar jag undersöka hur äldre reseguider kan utgöra sådana studieobjekt och därför kommer reseguider om Tallinn från Estniska SSR utgivna mellan 1960 till 1990 användas i historiebruksundersökningen. Analysen utgår från historieprofessorn Klas-Göran Karlssons typologi med sju olika historiebruk – ett vetenskapligt, ett existentiellt, ett moraliskt, ett ideologiskt, ett politiskt-pedagogiskt, ett icke- bruk av historia och ett kommersiellt. Undersökningen har belyst flera olika historiska dimensioner i reseguiderna och motiv till varför de kan analyseras. Resultatet av undersökningen visar på fyra punkter. Den första är att reseguiderna kan agera medium vid existentiell orientering. Den andra att de kan fungera som kommunikations-, kunskaps- och intresseprocess. Den tredje punkten är att de kan utveckla ett kritiskt förhållningssätt och fjärde punkten handlar om att reseguiderna kan vara motiv för att “sälja” historia vid utvecklingar av olika kommersiella produkter inom exempelvis turismen. Likaså att reseguiderna kan nyttjas och analyseras av antigen en individ eller grupp som känner behov, önskan eller intresse

Treatment of packaging board whitewater in anaerobic/aerobic biokidney

Whitewater from production of packaging board was treated in a combined anaerobic/aerobic biokidney, both in laboratory scale and pilot plant experiments. Both the laboratory experiments and the pilot plant trial demonstrate that a combined anaerobic/aerobic process is suitable for treating whitewater from a packaging mill. It is also possible to operate the process at the prevailing whitewater temperature. In the laboratory under mesophilic conditions the maximal organic load was 12 kg COD/m(3)*d on the anaerobic reactor and 6.7 kg COD/m(3)*d on the aerobic reactor. This gave a hydraulic retention time, HRT, in the anaerobic reactor of 10 hours and 2 hours in the aerobic reactor. The reduction of COD was between 85 and 90% after the first stage and the total reduction was between 88 to 93%. Under thermophilic conditions in the laboratory the organic load was slightly lower than 9.6 COD/m(3)*d and between 10 and 16 COD/m(3)*d, respectively. The HRT was 16.5 and 3.4 hours and the removal was around 75% after the co anaerobic reactor and 87% after the total process. For the pilot plant experiment at a mill the HRT in the anaerobic step varied between 3 and 17 hours and the corresponding organic load between 4 and 44 kg COD/m(3)*d. The HRT in the aerobic step varied between 1 and 6 hours and the organic load between 1.5 and 26 kg COD/m(3)*d. The removal of soluble organic matter was 78% in the anaerobic step and 86% after the combined treatment at the lowest loading level. The removal efficiency at the highest loading level was about 65% in the anaerobic step and 77% after the aerobic step. In the pilot plant trial the removal efficiency was not markedly affected by the variations in whitewater composition that were caused b y change of production. The variations, however, made the manual control of the nutrient dosage inadequate co and resulted in large variations in effluent nutrient concentration. This demonstrates the need for an automatic nutrient dosage system. The first step towards such a system was to evaluate two different on-line instruments. Both had severe stability problems, which made them unsuitable as parts in a system for control of the nutrient dosage

Treatment of packaging board whitewater in anaerobic/aerobic biokidney

FIGURE 18. Plot of length of pinnular 6 versus maximum cirrus length for Lamprometra palmata and L. p. form brachypecha

Biological treatment of whitewater in a laboratory process in order to determine kinetic parameters for model development

Implementation of an in-mill biological treatment plant is one solution to the problems associated with closure of whitewater systems. It is, however, important to operate the treatment with low concentration of nutrients in the effluent. The effect on the COD reduction from decreased additions of NH4-N and PO4-P were investigated in three parallel aerobic suspended carrier reactors during treatment at 46 to 48degreesC of whitewater from a recycled paper mill producing liner and fluting. In the reference reactor, a COD reduction of 89% was achieved and 45.6 mg NH4-N/(g COD reduced) and 11.6 mg PO4-P/(g COD reduced) was consumed at an organic load around 20 kg COD/(m(3.)d). Reduced additions of NH4-N decreased the COD reduction. Addition of 56% of the consumption of NH4-N in the reference reactor resulted in a COD reduction of 80%. The response from decreased addition of PO4-P was different compared to NH4-N but it could not be determined if this is due to unsuitable experimental design or a different reaction mechanism. Reducing the addition of PO4-P to 26% of the consumption of PO4-P in the reference reactor, decreased the COD reduction to 83%. The main conclusion from the experiment is: biological treatment has the potential of treating whitewater from recycled paper mills with low effluent nutrient concentrations