Thesis submitted in the requirements for the degree Doctor Technologiae: Chemical Engineering in the Faculty of Engineering at the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2013 / To date, limited information has been published on textile wastewater treatment, for re-use, in South Africa (SA), with treatment processes focusing on conventional wastewater treatment methods. A large contributor to the contamination of water within textile industries is from dyehouse processes. A major concern in textile wastewater treatment is the release of azo dyes and their metabolites, some of which are carcinogenic and mutanogenic, into the environment since they are xenobiotic and aerobically recalcitrant to biodegradation. A necessity therefore exists to find an effective treatment method capable of removing both the strong colour and the toxic organic compounds from textile wastewater. Membrane bioreactors (MBRs) are favoured when treating high-strength wastewater, since the membrane area is determined by the hydraulic throughput and not the biological load; no sludge is wasted and all bacteria are retained within the reactor, including specific bacteria capable of degrading the toxic, non-biodegradable constituents present in textile wastewater. MBR systems, using various configurations have been utilised extensively in the rest of the world to treat textile wastewater at both lab and pilot-scale. This DTech project formed part of a collaborative Water Research Commission (WRC) funded project K5/1900 - Pilot application of a dual-stage membrane bioreactor (dsMBR) for industrial wastewater treatment. The main purpose of this study was the on-site evaluation of a pilot-scale dsMBR incorporating two ultrafiltration (UF) sidestream membrane modules for the treatment, recovery and re-use of textile wastewater. The objectives of this project were to determine the treatment efficiency of the system; to evaluate the degree of colour removal from the textile wastewater; to improve residual colour removal within the system using treatment processes, such as NF and RO, as well as to propose a design and cost for a full-scale plant. A textile industry located in Bellville, Western Cape, was chosen as the industrial partner for the on-site evaluation of a semi-automated pilot wastewater treatment MBR plant using two 5.1 m2 Norit X-flow AirliftTM membrane modules. Since the wastewater treatment system was located on the premises, real continuously changing industrial wastewater was being treated. The industrial textile wastewater was treated in a series of tanks: 1) an anaerobic tank, which cleaved the azo bonds of the reactive dyes; 2) an anoxic tank containing reduced amounts of dissolved oxygen, in which denitrification occurred; and 3) an aerobic tank, in which i) nitrification, as well as ii) mineralisation of the aromatic amines occurred. The UF-membrane modules would account for the removal of any organic material. The wastewater stream was characterised by a chemical oxygen demand (COD) range of between 45 to 2,820 mg/L and an average biological oxygen demand (BOD) of 192.5 mg/L. The dsMBR achieved an average COD reduction of 75% with a maximum of 97% over the 220 day test period. The COD concentration obtained after dsMBR treatment averaged at 191 mg/L, which was well within the City of Cape Town industrial wastewater discharge standard. The average reduction in turbidity and TSS was 94% and 19.6%, respectively, during the UF-MBR stage of the system. Subsequent treatment of the UF permeate with nanofiltration (NF) for 4 days, alternated with reverse osmosis (RO) for 14 days removed both the residual colour and salt present in the UF permeate. A consistent reduction in the colour of the incoming wastewater was evident. The colour in the wastewater was reduced from an average of 659 ADMI units to ~12 ADMI units in the NF permeate, a lower American dye manufacturing index (ADMI) (i.e. method of colour representation) compared to the potable water (~17 ADMI units) utilised by the industrial partner in their dyeing processes. The colour was reduced from an average of 659 to ~20 ADMI units in the RO permeate, a lower ADMI and therefore colour when compared to the potable water. An average conductivity rejection of 91% was achieved with conductivity being reduced from an average of 7,700 to 693 μS/cm and the TDS reduced from an average of 5,700 to 473 mg/L, which facilitated an average TDS rejection of 92%. Based on the composition of the UF permeate fed to the RO membrane a maximum removal of 98.7% was achieved for both conductivity and total dissolved solids (TDS). The proposed full-scale plant would incorporate a UF-MBR system, followed by NF, RO, flocculation and a filter press. Therefore, the two waste products produced during operation of the proposed full-scale plant, would be the solid filter cakes and the liquid filtrate from the filter press. Implementing the proposed full-scale plant it would cost the industrial partner an operating cost of ZAR 113.85 and ZAR 3,415.49 to treat 97.1 m3 and 2,913 m3 of textile wastewater, respectively, per day and per month. This results in an annual saving of ZAR 845,848 on potable water expenses. This research, would provide SA textile industries, with an option to: 1) reduce their water consumption, thereby utilising less of a valuable decreasing commodity; 2) meet the SA government discharge standards and reduce their discharge costs; 3) reduce their carbon footprint (i.e. reduce their impact on the environment) by re-using their treated wastewater and therefore using less water from the municipality; and 4) decrease their annual expenditure on water, since the treated wastewater would be available for re-use.

Neste trabalho são apresentadas algumas características físicas, vantagens e viabilidade do uso do pó de tecido, proveniente do processamento de resíduos têxteis que são descartados em confecções em geral. A produção e utilização desse tipo de pó diminui o impacto ambiental e se mostra viável economicamente, pois é produzido facilmente a partir do processamento de resíduos, que seriam descartados na natureza. O presente trabalho mostra o estudo da produção do pó de tecido e a sua substituição parcial do agregado miúdo natural na produção de concretos de cimento Portland convencionais. Para comprovar a viabilidade técnica e econômica do uso do pó de tecido foram analisadas características do agregado como sua composição granulométrica, e seu comportamento nos ensaios de abatimento tronco de cone (Slump Test). Uma relação água-cimento também foi convencionada a um concreto usual com resistência esperada de 27MPa. Com estes dados foi definido um traço para o concreto utilizando 5% e 15% de agregado pó de tecido, substituindo a areia. A pesquisa apresenta os resultados de resistência à compressão simples dos corpos de prova cilíndricos de concreto aos 28 dias. Verificou-se que as amostras não apresentaram diferenças significativas de resistência entre si, tão pouco com relação às resistências de um concreto convencional produzido somente com agregado miúdo natural. Entretanto, houve uma melhora nos resultados dos ensaios à compressão, principalmente no concreto com 15% de pó de tecido. / On this work are present some physical characteristics, advantages and viability of the use of the fabric dust, proceeding from the processing of textile residues that are discarded in confections in general. The production and use of this type of dust diminish the ambient impact and if it shows economically viable, therefore it is produced easily from the processing of residues, which would be discarded in the nature. The present work shows to the study of the production of the dust of tissue its partial substitution of the natural small aggregate in the production of concrete of Portland cement conventional. To prove the viability economic technique and of the use of the fabric dust they had been analyzed characteristic of the aggregate as its grain sized composition, and its behavior in the discouragement assays cone trunk (Slump Test). A relation water-cement also was stipulated to the one usual concrete with resistance waited of 27 MPa. With these data a trace for concrete using 5% and 15% of added fabric dust, substituting was defined the sand. The research presents the results of simple compressive strength of the cylindrical bodies of test of concrete to the 28 days. It was verified so little that the samples had not presented significant differences of resistance between itself, with regard to the resistance of a conventional concrete only produced with natural small aggregate. However, the compression had an improvement in the results of the assays, mainly in the concrete with 15% of fabric dust.

This diploma thesis is focused on a suitable midification of acoustic and thermal insulation materials from recycled textile fibres of lower quality due to improvement of their reaction to fire. The aim is to find an effective flame retardant and to verify suitable method of flame retardant application onto this type of insulation material.

West Africa’s textile and clothing (T&C) industries have persevered through the decline following the economic liberalization policies in the 1980s. This thesis seeks to explore the sustainable and circular business models which exist in the West African region. It also explores the ways that businesses relate to the social conditions of poverty, a small T&C industry, strong competition from imports, and the concentrated levels of imported textile waste. Through a qualitative methodology, secondary data is collected on thirty T&C businesses in West Africa. These businesses are analyzed through the framework of the eleven sustainable business model (SBM) pattern groups by Lüdeke-Freund, et al. (2018). In the results, five main SBM pattern groups emerge: Supply Chain, Social Mission, Closing-the-Loop, Eco-design, and Cooperative pattern groups. Most of the businesses do not fall neatly into one pattern, but rather embody various hybrid sustainable business models. West Africa is unusual in facing both high poverty rates and textile waste landfills, which may influence the multi-dimensional approach to sustainability. By working with the local textile value chain and artisan communities, the thirty businesses contribute to poverty alleviation. They also pave the way for ‘artisan futurism,’ where handicraft is combined with circularity and eco-design initiatives, leading the West African T&C industry into the future.

[pt] Este trabalho expõe uma revisão da literatura acadêmica e jornalística sobre a sustentabilidade da moda e um estudo de campo sobre o lixão de roupas do Atacama. O objetivo é ser um compêndio sobre os impactos da indústria da moda e trazer iniciativas que visem minimizá-los. A moda é a segunda indústria mais poluente do mundo. Representa 2 por cento do PIB mundial, mas contribui com 8 por cento do total de emissão do carbono. É a segunda que mais consome água: 10 por cento do abastecimento e 20 por cento da poluição da água industrial global. Mais de 90 milhões de toneladas de resíduos têxteis vão parar nos aterros sanitários ao ano, sendo que um quarto é incinerada com alto impacto pelo uso de fibras sintéticas. O maior desafio da moda é ser circular e sustentável. Um dos exemplos emblemáticos do impacto da moda no meio ambiente é o descarte ilegal de roupas do deserto de Atacama, no Chile. Em 2021 foi noticiado como o maior lixão da moda do mundo com 300 hectares. Em 2023, através de pesquisa de campo foram encontradas 100 áreas de descarte de roupas: 50 dessas áreas com queimadas, 16 com descartes de roupas e 34 de outros tipos de descartes misturados. Foi observado que esse descarte ilegal tem um impacto social grande na região, onde a economia ao redor foca em peças coletadas para o sustento das famílias pobres. O estudo local e de imagens de satélite permitiu constatar mudanças na dinâmica do descarte ilegal. Muitos são os atores na cadeia da moda e cada um pode mudar os hábitos para termos uma moda menos poluente. Os designers podem utilizar modelagem eficiente, economia circular, upcycling, reciclagem, uso de fibras biodegradáveis em prol da sustentabilidade. Já o consumidor pode apoiar a economia circular, ser consciente com compras, lavagem de roupas, suas peças e a rastreabilidade dos materiais e processos utilizados na peça. / [en] This work presents a review of the academic and journalistic literature on the fashion sustainability and a field study on the Atacama clothing dump. The objective is to be a compendium on the impacts of the fashion industry and bring initiatives that aim to minimize them. Fashion is the second most polluting industry in the world. It represents 2 percent of world GDP but contributes 8 percent of total carbon emissions. It is the second largest consumer of water: 10 percent of the supply and 20 percent of the global industrial water pollution. More than 90 million tons of textile waste end up in landfills each year, a quarter of which is incinerated with high impact due to the use of synthetic fibers. Fashion s biggest challenge is to be circular and sustainable. In 2021 the largest illegal fashion dump in the world with 300 hectares was reported in Chile. In 2023, through field research and georeferencing, 100 clothing areas were found: 50 with fires, 16 with discards and 34 with mixed waste. The economy around the dump focuses on pieces collected for the livelihood of poor families. The local study and satellite images allowed us to observe changes in the dynamics of illegal disposal. Designers can use efficient modeling, circular economy, upcycling, recycling, use of biodegradable fibers forsustainability. Consumers, on the other hand, can support the circular economy, be conscious with purchases, washing clothes, their parts and the traceability of the materials and processes used in the part.