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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Biologisk vattenrening inom textilåtervinningsindustri : En utvärdering av Moving Bed Biofilm Reactor för att reducera BOD7 hos Renewcell

Ericsson, Jonas January 2021 (has links)
Klädindustrin är idag en stor bidragande orsak till negativa miljöpåverkningar. Om avtrycket från den industrin ska minska behöver det ”fast fashion” fasas ut och ett nytt sätt att se på kläder implementeras. De enklaste sätten att minska avtrycket är att återanvända eller återvinna kläder. Renewcell återvinner textilier och bryter ner bomullen och återvinner den som nytt material - Circulose®. Det materialet skickas vidare för att bli nya kläder och på så sätt stängs loopen för textilindustrin. Av produktionen av Circulose® tillkommer ett nytt slags processavlopp som inte hunnits forskas mycket på. Paralleller till textilindustrin kan visserligen dras och där är processavloppen av heterogen karaktär. Renewcell vill se om det går att reducera det organiska materialet i avloppet till en nivå på 10 mg/l. Den här studien vill hjälpa till att fylla det forskningsgap som finns för reningsteknik inom textilåtervinningsindustrin idag. Med en ny marknad i uppstart är det viktigt att avlopp hanteras på ett bra och ansvarsfullt sätt. Syftet med studien var att undersöka experimentellt och litterärt om det går att reducera ner BOD7 i Renewcells processavloppet till 10 mg/l. En MBBR har efterforskats och jämförts med en MBR, där en MBBR ansågs vara mer resistent mot variationer och farliga ämnen. Det byggdes en MBBR i laborationsskala kopplat till processavloppet för att analysera reduktionen av BOD7 och för att göra en experimentell undersökning hur den kemiska fällningen påverkas om vattnet behandlades biologiskt först. Studien resulterade i att Renewcells karaktär på processavlopp är heterogent och är hanterbart av mikroorganismer. Dock, på grund av att ingen fullt utvecklad biofilm nåddes samt variationer i processen är det fortfarande osäkert om det fungerar att implementera en MBBR hos Renewcell. Processförändringar som ett produktionsstopp är inga problem för en fullt utvecklad MBBR att hantera. Processavloppet innehåller en stor mängd organiskt material, men saknar tillräckligt med näringsämnen. För detta projekt var 58 % reduktion av BOD7 den högsta som redovisades och det nåddes inte heller en fullt utvecklad biofilm. Att biologiskt behandla avloppet innan en kemisk fällning gav positiva resultat då reduktionen av metalljoner förbättrades. Allt som allt anses det vara möjligt att implementera en MBBR hos Renewcell om rätt förutsättningar finns och det ges en möjlighet att utveckla en biofilm fullt ut. Förhoppningsvis kan denna förstudie visa vägen för vidare studier inom området. / The clothing industry is one of the major causes for negative environmental impacts. The “fast-fashion” needs to be phased out and a more climate-friendly way of using clothes implemented. The easiest ways to do this is to reuse or recycle clothes. Renewcell recycles used textiles and dissolve the cotton into pulp and makes a new material of it - Circulose®, which is sent to become new clothes and, in that way, helps to close the loop for textile industry. With the production of Circulose® a new kind of wastewater is produced which has not yet been thoroughly researched. A parallel to the textile industry’s wastewater can be drawn, and that is of heterogeneous nature and can change quickly from day to day. It is in Renewcell’s interest to reduce the organic matter in the wastewater, more than they do today with their current chemical and mechanic wastewater treatment plant does. This study wants to help fill the research gap that exists for purification technology in the textile recycling industry today. Since it is a new field of technology, it is of importance to thoroughly invest in how to treat the wastewater responsibly. The purpose of this study was to investigate, both experimentally and literary, whether the possibility to reduce BOD7 to 10 mg/l in the wastewater treatment plant. With an investigation of MBBR and by compare it with an MBR it was concluded that a MBBRis a better fit for Renewcell since it is considered to be more resistant to variations and hazardous substances. To strengthen that conclusion a MBBR in laboratory scale was built and wastewater directly from the recycling process treated. The reduction of BOD7 and how it would come to affect the chemical precipitation was analyzed. The results of the study concluded that Renewcells wastewater is heterogenous and manageable for microorganisms. However, the due to the variations in the process such as dosing of biologically harmful substances it might not be possible for Renewcell to implement a MBBR. Process variations as a stop in production of wastewater for a shorter time period is manageable. The wastewater contains enough organic matter, but an extra addition of nutrients is needed. For this project the MBBR-process fluctuated in reduction of organic matter and the highest amount achieved was 58 %. No fully developed biofilm was achieved either. Biologically treating the process effluent before the chemical precipitation gave positive results as the reduction of metal ions was improved. All in all, it is believed to be possible to implement a MBBR at Renewcell if the process is given the required conditions from the beginning and a biofilm can be fully developed. Hopefully, this pilot study can show the way for future research within the field.
22

Farbe als Herausforderung im Textilrecycling

Tomovic, Tina 30 June 2022 (has links)
Der Textilindustrie wird hinsichtlich umweltschädlicher Emissionen ein schlechtes Zeugnis ausgestellt. Bisweilen nimmt sie sogar einen unrühmlichen zweiten Platz ein und hat damit unweigerlich eine grosse Verantwortung um das global gesetzte 1,5-Grad Ziel (COP 21) zu erreichen. Konkret müssen bis 2030 die von diesem Industriezweig ausgehenden Treibhausgasemissionen um 45 % reduziert werden. Neben neuen Konsummustern und Geschäftspraktiken gilt es insbesondere die produktionsbasierten Emissionen zu vermindern (Berg, 2020).
23

Exploring feedstock supply chain for large scale manufacturing of recycled cellulosic textile fiber : A collaborative business model analysis

Rahman, SM Toufiqur January 2022 (has links)
The textile industry is considered one of the most challenging industries when it comes to environmental pollution just after the oil industry. It has a huge impact on water pollution and resource consumption in terms of fiber production. Recently sustainability in cotton fiber production is questioned due to the huge uses of land, water, a large number of pesticides, and a significant amount of energy during cultivation. When it comes to cellulosic pulp production, currently fibrous plant material is used which is mainly wood. So, recycling of cellulosic textiles is considered the only option to reduce this impact. The recycling company Renewcell is launching a large-scale plant for cellulosic fiber recycling which is located in Sweden and will use the post-industrial textile waste as one of its feedstocks. The purpose of this research is to analyze the barriers and drivers for collecting this post-industrial textile waste from the garment manufacturing countries to Sweden and analyze the available collaborative business model alternatives. This study was performed by a qualitative study where primary data was collected through semi-structured interviews and analyzed by thematic analysis. The data was collected among four stakeholders within this value chain which are the fashion brands, recyclers, garment manufacturers, and waste handlers. The finding shows that this sector is very informal and is yet to be formalized. The external informal influence was identified throughout the value chain as a non-value-added activity.  And the involvement of fashion brands was identified as one of the drivers. Several collaborative business models are discussed considering their applicability in different contextual situations. This analysis was discussed based on the seven themes which were generated during the thematic analysis and later discussed with the current empirical study and theoretical background. Collaboration between the recycler, traders, brands, and the textile manufacturers were discussed in different dimensions such as direct collaboration and logistic partnership approach. Then the research limitation was discussed in both methodological and research contexts followed by future research recommendations.

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