Thesis (MEng (Chemical Engineering))--Cape Peninsula University of Technology, 2018. / Advanced oxidation processes (AOPs) have gained considerable interest in the wastewater treatment industry. Low selectivity to organic pollutants and the high oxidation potentials provided by the free radicals produced from these processes are the root of this interest. Hydroxyl radical based AOPs seemed to dominate the field but recently sulphate radical based AOPs started to become more popular due to their even higher oxidation potential. The textile industry is known to be a considerable contributor to wastewater production. Many pollutants in this wastewater are organic pollutants which are very persistent to the more traditional treatment processes such as biological treatment and membrane filtration. Numerous studies have shown the potential and success of catalytic AOPs for the degradation of organic pollutants in wastewater. One such process is the use of a cobalt oxide nano-catalyst in conjunction with a peroxymonosulfate (PMS) oxidizer (Co3O4/PMS). The shortcoming with nano-catalysts however are the difficulty of recovering the catalyst in a slurry system or the effective immobilization of the catalyst in a continuous system. To address the issue of nano-catalyst immobilization, two different methods were used in the study to effectively immobilize the catalyst in a substrate. The methods were compared by utilizing the permeable reaction barriers in a continuous flow reactor. A bench scale reactor of 2.4 L/hr was designed and used to study the effect of PMS, catalyst mass and flow rate on the degradation efficiency and to determine the residence time and catalyst per PRB cross-sectional area ratio. A scale up rationale was formulated based on a constant residence time and the catalyst mass per PRB cross-sectional area ratio. Two design correlations were developed to predict the size of the permeable barrier and the catalyst mass required for the scale up PRB system. These parameters were used to design a reactor 30 times that of the bench scale reactor. In both reactors the optimum degradation occurred within 2 minutes indicating the success for catalyst immobilization and the development of a continuous reactor utilizing the Co3O4/PMS advanced oxidation technology.

Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2017. / Similar to the energy crisis, the critical state of the water supply in South Africa (SA) is a combination of (i) resource exhaustion and pollution; (ii) increasing demand; and (iii) poor infrastructure. Despite its importance, water is the most poorly managed resource in the world. The disposal of industrial effluents contributes greatly to the poor quality of water. The textile industry consumes great quantities of water and produces enormous volumes of wastewater which requires appropriate treatment before being released into the environment. In an attempt to address the water issues, research globally has focused on advanced technologies such as desalination to increase limited pure water resources. The need for alternative desalination methods for the production of clean water from alternative water resources, such as seawater and brackish water, has gained worldwide attention. Reverse osmosis (RO) and Nanofiltration (NF) have been used as unswerving approaches to yield freshwater. Forward osmosis (FO) is a developing membrane technology that has increased substantial attention as a possible lower-energy desalination technology. However, challenges such as suitable FO membranes, membrane fouling, concentration polarisation, and the availability of effective draw solutions (DS), limit FO technology. FO is seeking more importance in novel areas where separation and recovery of the DS is not required. The aims of this study was to: i) identify alternative water resources and evaluate their potential as suitable feed solution (FS); ii) Identify dyes and evaluate their potential as suitable draw solutions (DS) at different concentrations; iii) assess the use of aquaporin biomimetic membrane and iv) assess a FO system for the production of dye solutions. Osmotic pressure (OP) is the pressure exerted by the flow of water through semi-permeable membrane, separating two solutions with different concentrations of solute. The DS should always have OP higher than the FS in order to achieve high water flux. Three basic dyes (i.e. Maxilon Turquoise, Red and Blue) and three reactive dyes (i.e. Carmine, Olive Green and Black) were selected, based on their common use in the SA textile industry. The respective dye samples were prepared at different concentrations and dye-to-salt mass ratios ranging from 1:10 to 1:60 and assessed for OP using a freezing point osmometer. A lab-scale FO unit was used for all the studies. Feed and draw channels were circulated in a counter-current flow at a volumetric flow rate of 600 mL/min. Feed solutions(FS) included deionised water (DI) as a control, brackish water (BW), synthetic seawater (SSW) and textile wastewater (TWW) collected from two textile factories. OP of the FS (DI, BW5, SSW and SW, Factory 1 and Factory 2) was 0, 414, 2761, 2579, 1505 and 3308 kPa, respectively. Basic Blue and Reactive Black generated a higher OP compared to other selected dyes in the study and were therefore selected to be used as DS at a 1:10 dye-to-salt ratio and 0.02 M concentration. An aquaporin biomimetic FO membrane (Aquaporin, Denmark) was used for all the experiments conducted in the FO mode.

In 2015 the global fibre consumption was 96.7 million tonnes, which is an increase of 3.1% from the year before. Our high textile consumption has led to an increasing demand of raw materials and generation of textile waste. Only in Europe, a total amount of 4.3 million tonnes of apparel waste each year is sent to either incineration or landfills. Approximately 50% of the clothes we discard and donate are composed of cotton. In the future, the cotton production is predicted to stagnate since the world population is increasing and arable land to greater extent will be needed for food production. Thereby, it is important that we utilize the cotton waste generated. One of the most commonly used processes for recycling textile waste is the shredding process. In this method, textile waste is shredded back into their constituent fibres. The drawback with the shredding process is that the fibre length is reduced. The fibre length is an important property since it has a high influence on textile processing such as yarn production and final product quality. The aim of this thesis was to investigate how post-consumer cotton garments with different degree of wear affects the fibre length obtained in the shredding process. This was performed by analysing the input fibre length as well as the output fibre length. Additionally, several parameters were investigated: fabric construction and yarn structure. Degree of wear was categorized into two levels: low and high degree of wear. The fabric constructions used in this study were single-jersey and denim. The yarn structure were analysed in terms of yarn count, yarn twist and manufacturing process.  The result showed that the fibre length before shredding was statistically significant longer for the materials with low degree of wear compared to high degree of wear. After shredding, it was shown that the fibre length reduction was lower for the materials with high degree of wear. This indicates that longer fibres give higher fibre length reduction. In addition, it was found that finer yarn gives higher fibre length reduction. The result also showed that the yarn manufacturing process has a great influence on the ease of shredding and the fibre length obtained in the end.  Based on the result in this thesis it can be concluded that the shredding process needs to be improved in order to preserve the fibre length. The area of post-consumer textile waste is complex and the result showed that there is many underlying parameters that need to be taken into account to further develop the shredding process.

The continuing industrial development has led to a corresponding increase in the amount of waste water generation leading to a consequential decline in levels and quality of the natural water in the ecosystem. Textile industries consume over 7 x 10[superscript 5] tons of dyes annually and use up to 1 litre of water per kg of dye processed and are third largest polluters in the world, the problem being aggravated by the inefficiencies of the dye houses. An abundance of physio-chemical methods are in use world wide, however, there is increasing concern as to their impact in effectively treating textile effluents as they introduce secondary pollutants during the ‘remediation’ process which are quite costly to run, maintain and clean up. Research on biological treatment has offered simple and cost effective ways of bioremediating textile effluents. While aerobic treatment of textile dyes and their effluents has been reported, its major draw back is commercial up-scaling and as such anaerobic systems have been investigated and shown to degrade azo dyes, which form the bulk of the dyes used world wide. However, the mechanisms involved in the bioremediation of these dyes are poorly understood. The aims of this study were to identify and investigate the role of enzymes produced by sulphate reducing bacteria (SRB) in bioremediating textile dye and their effluents. Sulphate reducing bacteria were used in this study because they are tolerant to harsh environmental conditions and inhibit the proliferance of pathogenic micro-organisms. The appearance of clear zones in agar plates containing azo dye concentrations ranging from 10 – 100 mgl[superscript -1] showed the ability of SRB to decolourize dyes under anaerobic conditions. Assays of enzymes previously reported to decolourise azo dyes were not successful, but led to the identification of hydrogenase enzyme being produced by SRB. The enzyme was found to be localised in the membrane and cytoplasm. A surface response method was used to optimize the extraction of the enzyme from the bacterial cells resulting in approximately 3 fold increase in hydrogenase activity. Maximum hydrogenase activity was found to occur after six days in the absence of dyes but was found to occur after one day in the presence of azo dyes. A decline in hydrogenase activity thereafter, suggested inhibition of enzymatic activity by the putative aromatic amines produced after azo cleavage. Purification of the hydrogenase by freeze drying, poly ethylene glycol, and Sephacryl – 200 size exclusion- ion exchange chromatography revealed the enzyme to have a molecular weight of 38.5 kDa when analyzed by a 12 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 40 °C while it exhibited a poor thermal stability with a half-life of 32 minutes. The kinetic parameters V[subscript max] and K[subscript m] were 21.18 U ml[superscript -1} and 4.57 mM respectively. Application of the cell free extract on commercial dyes was not successful, and only whole SRB cells resulted in decolourisation of the dyes. Consequently trials on the industrial dyes and effluents were carried out with whole cells. Decolourisation rates of up to 96 % were achieved for the commercial dyes and up to 93 % for the industrial dyes over a period of 10 days.

Supply chain management is found to be highly related to collaborations among stakeholders to create successful strategies for the supply chain. To leverage circularity in the textile and clothing industry, successful circular strategies that support the businesses in an economic and environmental manner are key. Through this research, the interconnection and communication between the relationships within the supply chain are found to be the most significant factor. In this qualitative study, the purpose of the research was to investigate how relationships and partnerships in the textile supply chain can affect and enable commercial scale for recycling of textiles-to-textiles. In-depth semi-structured interviews with six key stakeholders in the European textile industry. This study found that relationship characteristics such as trust, communication and strategic values through long-term relationships and key suppliers play an important role in realizing textile-to-textile recycling. Furthermore, findings confirm that the financial aspects are the most prominent condition for textile recycling to improve win-win partnership models to promote key operational conditions. With Europe having a leading position in the textile industry, the research study has geographically limited the empirical scope to solid focus on textile supply chain and business relationships in Italy to provide the study with accurate cluster accusation.

In light of the negative social and environmental impacts of the textile industry, a paradigm shift towards a more circular economy is inevitable. Automated textile sorting embodies a crucial but missing link to connect forward and reverse supply chains for circular economy, however scalability challenges exist. Therefore, the study explores how dynamic capabilities can overcome scalability challenges specific to automated textile sorting pilots in Northwestern Europe to create commercially viable solutions. A single case study using an abductive approach guided by the dynamic capabilities view explores automated textile sorting pilots’ approaches to dynamic capability microfoundations. Primary data include semi-structured interviews, which is complemented by secondary data documents, and both were analysed qualitatively via thematic analysis. The data reveal that known scalability challenges remain and new scalability challenges related to market disruptions exist, such as COVID-19. Scalability challenges are overcome through novel approaches to the microfoundations undergirding dynamic capabilities. These are found to take place in a continuous, overlapping process, and collaboration is found across all dynamic capabilities. As collaboration plays a prominent role, it should be integrated in approaches to dynamic capabilities. This study also adds to the literature on circular economy in the textile industry by confirming that known scalability challenges for automated textile sorting pilots remain, and new scalability challenges are developing in terms of market disruptions. Actors in the automated textile sorting supply chain may use these findings to support efforts to scale up automated textile sorting. For textile industry brands and recyclers, the findings can assess their readiness to participate in the automated textile sorting supply chain and support the achievement of their 2030 goals to use greater volumes of sorted textile waste fractions as feedstocks for their production processes and to be a collaborative member of the used textiles supply chain.

The value consumers attach to their clothing creates a high demand and frequent consumption of fast fashion. This results in the increase of post-consumer textile waste that ends up on landfills, which has a negative impact on the environment. This raises the critical issue of disposal methods and necessary education to create awareness and equip users to contribute to a circular economy that aims to extend the lifecycle of each garment. This study aims to design for the facilitation of a circular economy driven by post-consumer textile waste that encourages sustainable consumption. The short lifecycles of commercial interior due to the influence of societal taste results in the frequent alteration of these interiors, increasing building waste which has a negative environmental impact. This study explores how the lifecycle of an interior environment can be extended through the design principles derived from the design informants identified through the investigation of the theoretical framework, site, precedents, users and programme, and proposed brand. The result is the design of sustainable interior environments that encourages sustainable consumption. The design for multi-use programme allows for users to learn and contribute on various platforms to empower the local community and close the loop for fast fashion to generate a new fashion culture at 012 Central. Through the alteration of the identified interior environments the design intervention aims to reinvigorate the underutilised buildings at 012 Central to support a circular economy driven by post-consumer textile waste. The design intervention aims to provide an informative spatial experience that encourages interaction with space and object, empowering users to contribute to a circular economy driven by post-consumer textile waste. The technical resolution of the proposed design intervention is concerned with the design of sustainable interior environments and components that considers their environmental impact through a closed-loop design approach. / Mini Dissertation (MInt (Prof))--University of Pretoria, 2020. / Architecture / MInt (Prof) / Unrestricted

The textile industry is developing at a fast pace, and is constantly changing. It is constantly evolving new methods for recycling and further research is important for future needs. The ability to recycle a textile blended material is a step towards a more sustainable industry. There are however different difficulties around the various processes that have to be removed for recycling. The purpose of the study is to find methods for removing dyes from polyester and cotton blended textile waste for recycling. To investigate the subject, a literature study combined with interviews with experts was performed. The results of the study shows that it is possible to remove dye from cotton and polyester individually. To remove dye from cotton chlorine and hydrogen peroxide are used. Another method is to use a reducing agent hydrosulphite and after use together with lye. There are several ways to remove colour from polyester, although it will almost always have a residue of colour left. One can either melt the pigment into the fibre by using heat. Another method is to use chemicals which increase the amorphous areas in the fibres and the colour will be penetrated. Finally, when investigating a method for removing dye from a polyester and cotton textile blend. The study has highlighted the need of developing new methods without destroying the quality of the fibres. By this study it has been concluded removing dye from fibres are difficult but can be achieved with certain chemicals and processes. It is concluded in the study, removing dye from polyester and cotton individually can be succeed. However, removing colour from a blended fabric is rather difficult. The study has focus on discussing the difficulties when decolouring a blended textile.

Background: In recent years, the amount of textile waste increased rapidly due to the fast-fashion phenomena with an increasing clothing production and a declining customer usage. Not only that one truck of clothing getting landfilled or burned every second, but also the textile production impacts the environment due to the vast amount of water, material, chemical, and energy usage. This so-called linear “take-make-waste” approach contributes significantly to the current climate crisis. One possible solution represents the circular economy to encounter the linear approach by providing concepts for recovering materials. However, to our state of knowledge, the implementation of such Circular Economy (CE) approaches is far away from their urgent necessity. Literature papers from the last years conclude with a collaboration call between all industry actors for enhancing the waste recovery stream (WRS). Since digital platforms tackled the collaboration challenge of Circular Economy in other industries, we contemplated it as an adequate digital technology tool for overcoming Textile, Apparel and Clothing (TAC) industry collaboration challenge to further strengthening the WRS. Purpose: The study aims to investigate if and how digital platforms strengthen the TAC industry's WRS. For this purpose, we shed light on different challenges within the industry-wide network, analyzed current platform functionalities, and matched challenges and functionalities to answer the research question.  Method: The study adopts an inductive qualitative approach to explore the phenomenon of digital platforms and their potential as an enabler for the textile WRS. Thereby, we took a relativism view regarding our ontological position and followed a social constructionist's epistemology. For the data collection, we used semi-structured interviews and identified potential participants with criterion and snowball sampling. In total, we conducted 14-semistructured interviews with industry actors, platform providers, and experts. For our data analysis, we oriented ourselves on the Gioia Method, an articulated grounded theory approach. Conclusion: Resulting from our findings, we identified (1) four major challenge groups that go beyond the collaboration challenge and encompass the challenge of lack of knowledge, organization of WRS, and value chain structure. Further, we outlined (2) five platform functionalities, i.e., connecting, informing, visualizing, monitoring, and consulting. By matching challenges and functionalities, we analyzed (3) the extent to which DP can strengthen WR. We concluded that many industry challenges are tackled or partly tackled by the DP functionalities. However, within some of the sub-challenges as well as the overall challenge of the value chain structure, DPs reach their limitation in strengthening the WRS. In addition, we offer (4) an overall framework of DP for the WR stream, summarized how the DP tackles the industry-wide challenges by displaying the functionalities and associated value drivers. Lastly, we provide (5) the baseline for future platform functionalities by outlining actors’ expectations and platform providers’ planned functionalities arisen by our finding.

[pt] O objetivo deste trabalho foi o desenvolvimento de um produto a partir dos resíduos têxteis de confecção, em especial do tecido de viscose. O propósito do estudo é mostrar uma forma de reutilização de resíduos da confecção visando reduzir o tempo de descarte desse material. O trabalho buscou trazer uma alternativa que possibilitasse dar outra origem que não o descarte puro de restos de panos da confecção, produzindo papel tecido que será utilizado na própria confecção, como tags e caixas. Essa substituição pode levar à menor utilização de materiais de embalagens e diminuir a quantidade de lixo produzido em toda a cadeia de comercialização de roupas. O esforço desse estudo foi propor uma forma de reduzir a agressividade e a velocidade que os resíduos têxteis são gerados. Foi desenvolvido um produto a partir do resíduo da viscose como matéria prima, transformando lixo em papel de tecido fabricado a partir da releitura da técnica chinesa do século II d.C. a qual triturava trapos e galhos, levando a criação de produtos para uso papeleiro e com características próprias como cor de origem dos retalhos, boa maleabilidade, qualidade entre outros. Também foi realizada uma pesquisa sobre o potencial de decomposição desse papel de viscose no meio ambiente e como seria o seu processo de decomposição em diferentes tipos de superfície. Foi observado que os papéis de tecido se decompõem rapidamente, demonstrando inclusive melhor perda de material em comparação as tags comuns de papel produzidos pelas gráficas em geral. / [en] The objective of this work was the development of a product from textile waste, especially from viscose fabric. The purpose of the study is to show a way of reusing manufacturing waste in order to reduce the disposal time of this material. The work sought to bring an alternative that would make it possible to give another origin than the pure disposal of cloth leftovers from the confection, producing tissue paper that will be used in the confection itself, such as tags and boxes. This substitution can lead to less use of packaging materials and reduce the amount of waste produced throughout the clothing marketing chain. The effort of this study was to propose a way to reduce the aggressiveness and the speed at which textile waste is generated. A product was developed from viscose residue as a raw material, transforming waste into tissue paper made from the reinterpretation of the Chinese technique of the 2nd century AD. which shredded rags and twigs, leading to the creation of products for paper making and with their own characteristics such as the original colour of the patchwork, good malleability, quality, among others. Research was also carried out on the decomposition potential of this viscose paper in the environment and how its decomposition process would be on different types of surfaces. It was observed that tissue papers decompose quickly, even demonstrating better material loss compared to common paper tags produced by printers in general.