Mapping of Textile Waste Management Techniques and Conversion Pathways: A Bibliometric Review

1. Introduction

The textile industry is one of the oldest and largest globally, driven by demand and increase in population. Production grew from 70.6 million tons in 2007 to 123 million tons in 2023 and is expected to surpass 150 million tons by 2030 [1]. In 2024, the global textile market was valued at approximately $1.6 billion and is projected to reach 2.89 billion by 2032, growing at a compound annual growth rate (CAGR) of 6.8%. Fabrication of textiles starts with raw fibers that could be either natural (such as cotton, wool, silk, etc.) or synthetic materials (such as polyester, nylon, etc) [2,3]. They are then spun into yarn, woven, or knitted into fabric; after that, treated through dyeing and finishing processes. Finished textiles are transformed into garments, which are worn and maintained throughout their useful life [4]. At the end of their life cycle, these garments are either recycled into new materials or discarded as waste [5]. Textile waste is produced both during the manufacturing process and after consumer use. [6]. Currently, only 20% of textile and clothing waste is recycled or reused, while the remaining 80% is sent to landfills or incinerators, resulting in significant resource loss and environmental damage [7,8]. The wasted materials may be in the form of fibers, yarn, fabrics, along trims such as buttons, zippers, threads, laces, labels, dyes, chemicals, and effluent. These wastes represent serious concerns for the environment. Over the past two decades, significant studies have focused on strategies for textile waste management, reuse and recycling [8,9]. Mechanical and chemical recycling have been developed to convert textile waste into new fibrous materials, allowing for the creation of value-added products such as insulation, carpets, and new garments [10,11]. Biological recycling, which involves use of enzymes or microorganisms to break down fibers, is also gaining attention as a sustainable method for textile recycling [12].

The use of AI and machine learning technologies are playing a key role in enhancing textile waste management by improving sorting efficiency, predicting waste patterns, and optimizing recycling processes [13,14]. AI-driven sorting systems can identify and segregate materials more accurately, leading to better recycling outcomes [14,15]. Machine learning algorithms also facilitate the creation of more efficient processes for converting waste into useful products [16,17]. Policies like the EU Eco-design Roadmap, along with cross-sector collaborations, are key drivers of sustainability and waste reduction in the textile industry [18,19].

Previous studies on textile waste management often focus on specific recycling techniques or type of wastes (e.g., natural, bio-based, non-bio-based), with limited integration into holistic approaches [19,20,21]. However, studies related to the scalability of recycling technologies, innovative applications, and the role of AI [22,23,24,25] are still needed. Despite its significance, the field remains underexplored in terms of comprehensive literature reviews and bibliometric analyses, relying largely on empirical studies. This review is an attempt to address this gap by exploring innovative and eco-driven strategies for managing textile waste with the help of standard bibliometric data. It considers recovery techniques, reuse technologies and waste converting processes. Current and emerging methods for recycling and valorizing textile materials into high-value products are also reviewed in this paper. It further highlights the role of AI in textile waste management and valorization.

2. Methodology

The study uses Scopus database to explore research trends related to the subject of this review, following Preferred Reporting Items for systematic reviews and meta-analyses (PRISMA). Bibliometric analysis is performed with VOS viewer to generate knowledge maps based on co-authorship and keyword co-occurrence [25].

The methodology for this review study composed of three main subsections: (i) selection of the database and formulation of search criteria, (ii) determining selection criteria for literature, and (iii) suggesting research questions. The selection of relevant literature focuses on the management and valorization of waste in the textile supply chain and its various applications. The review considers relevant publications covering the period from 2005 to Sep 2025. The search process began with the Boolean search string:(“textile waste” OR “fabric waste” OR “garment waste” ) AND ( “management” OR “recycling” OR “valorisation” OR “value-added” OR “circular economy” OR mechanical recycling OR repurpose OR reuse OR reduce) AND (pubyear > 2004 AND pubyear < 2025) AND (LIMIT-TO (doctype, “ar” ) OR LIMIT-TO ( doctype, “cp” ) ). This string provided 3342 results. Further, additional keywords were incorporated to refine and optimize the search results. These include: Textiles, Textile Industry, Cotton, Dye, Textile Waste, Textile Wastewater, Textile Fibers, Yarn, Cotton, Wool, Weaving, Dyeing, Polypropylene, Polyester, Spinning, Reuse, Textile Recycling, Nonwoven fabrics, Textile Effluent, Textile Processing, Textile Finishing, Garment and Clothing. Inclusion and exclusion criteria were applied to refine the search results, filtering out 2693 studies that met the established parameters [30].

Inclusion criteria consider the following:

• Research covering any category of textile waste, primarily solid waste and sludge.
• Studies focusing on the collection of textile waste and management from pre-spinning to post-consumer waste.
• Novel applications of textile waste management, valorization of textile waste, and conversion into value-added products.
• Studies in various geographical locations and different types of textile manufacturing.

Exclusion criteria include the following:

• Studies focusing on by-products not originating from the textile industry.
• Studies focusing on only environmental impact assessment or life cycle assessment.
• Duplicate studies, with preference given to publications ranked higher in the research hierarchy.

Lastly, the selected papers were analyzed based on predefined research questions, ensuring the extraction of essential insights needed to formulate conclusions on the effective utilization of textile waste in various applications. This review suggests the following research questions:

• What type of textile material is used, and which method(s) are applied in management and conversion?
• What is the application, and is it relevant to the scope of this study?
• Is there any novelty in the methodological process, and is the proposed application feasible?
• What are the key control parameters, indicators, and challenges against valorization in each study?
• Does the utilization of the proposed waste comply with environmental regulations?

A knowledge map was constructed with the help of bibliometric analysis on the VOS viewer software. The knowledge map displays the connections between authors and their countries, considering collaborations and the co-occurrence of prominent keywords. Co-occurrence analysis highlights the relationship between author keywords, showing which keywords frequently appear together in different publications.

3. Analysis and Discussion

This section addresses the research questions outlined earlier, focusing on the central theme of textile waste management and valorization. Only carefully selected articles are considered to provide quality insights and suggest valuable recommendations for future work.

3.1. Bibliometric Analysis

Publication trends in the field of textile waste management and valorization show a clear upward trajectory over time (Figure 1). From 2005 to 2013, the number of documents remained relatively low and stable. However, a gradual increase began in 2014, with a sharp increase from 2018 onward. The number of publications reached its highest point in 2024, totalling 422. This pattern reflects a growing academic and research interest in the field over the past decade.

As depicted in Figure 2, the data indicate a worldwide distribution of research activity. China leads by a significant margin, contributing 388 documents, followed by India with 222 and Turkey with 161. The United States, Spain, and the United Kingdom also reveal strong engagement. A broad range of countries across Asia, Europe, the Americas, and Africa are represented, reflecting the widespread interest and research in textile-related topics. While developed countries dominate the top ranks, emerging economies like Pakistan, Malaysia, Romania, and Bangladesh also show notable contributions, indicating a growing global focus and collaboration in this area.

Figure 3 presents worldwide knowledge map overlay of textile waste management and valorization based on author keywords co-occurrence. From the dataset, a total of 1,330 keywords were initially extracted. Due to VOSviewer’s threshold, which allows analysis of up to 1,000 keywords at a time, the software selected the most frequently occurring words/terms. After consolidating synonyms and similar phrases, the final list included 988 distinct keywords, each appearing at least twice.

According to the co-occurrence network presented in Figure 3, the term “recycling” emerged as the most significant keyword, showing 309 connections, a total link strength of 833, and 309 occurrences. Other frequently associated terms include “textile waste” (273 links, 592 total link strength, 240 occurrences), “circular economy” (237 links, 571 total link strength, 200 occurrences), “sustainability” (215 links, 460 total link strength, 153 occurrences), “cotton” (159 links, 271 total link strength, 86 occurrences), “textile wastewater” (138 links, 245 total link strength, 123 occurrences), “reuse” (106 links, 185 total link strength, 164 occurrences), and “mechanical properties” (103 links, 198 total link strength, 79 occurrences).

The prominence of large nodes associated with keywords such as recycling, textile waste, circular economy, and sustainability indicates that these are central themes in textile waste management research. Figure 4, which presents the keyword density visualization, highlights the research focus around these core topics. The knowledge map further illustrates that dense areas cluster around terms like recycling, textiles, circular economy, and sustainability, while gradually expanding toward related concepts such as wastewater, cotton, polyester, biomass, biodegradation, reuse, reduction, and Internet of Things.

3.2. Generated Waste in the Textile Product Life Cycle

Waste generated in the textile product life cycle can be divided into three categories: during manufacturing, during use, and post-consumption [26]. Figure 5 illustrates the stages for the textile product life cycle, while Table 1 displays an overview of waste generation throughout the textile product life cycle from spinning to post-consumer stages, listing waste types, estimated amounts, and potential for reuse or recycling. Waste is generated at various processes, including fiber extraction, ginning, spinning, weaving (weaving, knitting, nonwoven manufacturing), chemical processing, dyeing, printing, finishing, garment manufacturing, and retailing [6]. Worth mentioning that waste generated in these processes can often be reused within the same cycle after cleaning, mending, or refurbishing. However, certain portion of the waste can not be reused and must be recycled. Table 1 and Figure 5 also depict that seeds, seed coats, vegetable material, Peduncle waste, pupae waste, cocoon waste, fiber, yarn, fabrics, dyes, chemicals, trims, and accessories are the common waste generated in the textile manufacturing supply chain [4,27]. Waste generated during the use phase of textiles primarily originated from such activities as washing, dry cleaning, and regular wear and tear. Washing contributes to water pollution through detergent residues, dye runoff, and the release of microplastics from synthetic fibers [28]. Dry cleaning generates chemical waste, particularly from solvents like perchloroethylene, which can be harmful to the environment. Additionally, repeated washing and drying cause fiber degradation, leading to fabric abrasion, thinning, pilling, and eventual disposal. Wear and tear over time also result in textile waste as garments become damaged, faded, or out of shape, prompting users to discard or replace them. Post-consumption waste includes discarded garments, household textiles, and misfit clothing, which may be resold, donated, repurposed, and recycled [29,30].

Textile waste is normally disposed of through outlets, industry tie-ups, jobbers, or non-profits. It is either sent to landfills, reused, incinerated, or recycled. Landfills pose significant environmental risks, with natural fibers taking weeks to years to decompose and synthetics, requiring 30–40 years or more, releasing harmful gases and pollutants [31]. To minimize environmental impact, reuse and recycling are preferred over incineration and landfilling, as they reduce virgin fiber production and additional processing. However, textile recycling becomes more complex with blended materials, requiring efficient separation systems during production for better recyclability [3,6,32].

3.3. Processes for Converting Textile Waste into Value-Added Products

Conversion of the textile waste involves the collection, sorting, and processing of the waste. Accurate recognition and sorting of textiles are the keys to the process of converting them into value-added products. Identifying textile fibers is particularly challenging due to complex fabric structures, colors, and added garment components like zippers and buttons [14]. Manual sorting remains common, with limiting scalability, and traditional methods, such as microscopy, are slow and often ineffective at distinguishing similar compositions (cotton, Viscose) or synthetic fibers [15]. Advanced technologies, such as Near-Infrared (NIR) and Fourier Transform Infrared (FTIR) spectroscopy, have shown high accuracy in fiber identification and offer potential for automation, although each has limitations with coated fabrics and core yarns. While thermal analysis techniques also aid in identification, their destructive and time-consuming nature make them less practical for large-scale recycling [20,21]. AI and machine learning are streamlining the process of sorting and classification [16,17]. After sorting, textile waste can be converted into value-added products using various technologies. These technologies involve reduce, reuse, recycle, or recover technologies [33,34]. Other studies [35,36,37,38] classified these techniques into four specific recycling methods: Primary recycling, which uses industrial textile waste in its original form, for example use of spinning waste to make open-end yarn [19,37]. Secondary recycling (mechanical), which involves cutting or shredding textiles into fibers to create new products such as garments, insulation, or padding. Tertiary recycling (chemical), which breaks textiles into chemical components using such methods as pyrolysis or hydrolysis, allowing materials like polyester to fabricate new fibers. Quaternary recycling involves the recovery of energy by incinerating non-recyclable textiles to produce heat or electricity [21,39,40]. While primary and secondary methods are more sustainable, tertiary and quaternary methods are useful to manage hard-to-recycle waste. Figure 6 presents the various approaches for the valorization of textile pre- and post-consumer waste. For a deeper understanding, 202 publications are identified as the most relevant from a bibliometric database of 2,693 papers covering the period 2005–2024, which focus specifically on waste management strategies such as reducing, reusing/repurposing, and recycling/recovering. As shown in Figure 7a, the analysis reveals that recycling/recovery is the most frequently studied topic (122 papers), followed by reuse/repurposing (51 papers) and reduction (29 papers). Further, the bibliometric analysis reveals that out of 122 studies on recycling, chemical recycling shares the largest at 44.26%; this is followed by mechanical recycling at 28.68%, biological recycling at 22.13%, and combined recycling processes at 4.91% (Figure 7b).

3.3.1. Reduce and Reuse (2R) for Textile Waste

Reduce aims to minimize textile waste t by promoting efficient production, sustainable materials, and conscious consumption. It involves optimizing resources and adopting slow fashion practices [31]. In the yarn manufacturing industry, two types of waste, namely soft (fiber) and hard waste (yarn), are produced. Reducing waste in the spinning industry requires a systematic approach to managing this waste at various stages of production, as shown in Table 1 [10,13]. In the blowroom, waste may include such materials as droppings, seed coats, dust, dirt, and floor sweepings. These can be reduced by ensuring optimal cleaning efficiency through proper maintenance of machine components such as beater spikes, grid bars, and feed rollers [37,38]. Ensuring optimal beater speed, fan speed, and grid bar settings can reduce waste generation. In carding, waste may include such materials as flat strips, licker-in waste, sliver cuts, and filter waste. Controlling waste involves adjusting licker-in speed, wire point density, and flat strip settings to enhance cleaning efficiency while minimizing lint loss [8,10]. In the ring frame, soft waste includes pneumaphill (bonda) waste, and hard waste includes faulty yarn bobbin and traveler waste. To reduce breakages, waste can be minimized by optimizing drafting parameters, such as spindle speeds and traveler selection [6,10,33]. Proper maintenance of top rollers, aprons, and ring travelers can prevent defective yarn production. Also, maintaining humidity (50-55%) helps control static electricity, reducing fiber fly and uncontrolled waste generation. In the autoconer (winding), waste is resulted from yarn clearing, splicing, and package formation [38]. Pneumafil suction waste, clearer waste, and filter waste can be minimized through precise yarn-clearing settings, proper calibration of tension and splicing parameters, and regular maintenance of suction nozzles, sensors, and cutters. Minimizing waste in weaving processes (Table 1) requires optimizing parameters across various stages, including warping, sizing, loom operations, and defect management [40,41]. A recent study emphasizes the importance of maintaining optimal relative humidity levels in the loom shed to reduce warp breakages and enhance efficiency; the study reveals that adjusting relative humidity can greatly reduce warp yarn breakage, improve loom productivity, and minimize waste [39]. Additionally, integrating AI-driven machine vision systems in the weaving process enables precise real-time defect detection, allowing early identification and rectification of flaws. Minimizing waste in the dyeing process requires optimization across various parameters, including water and chemical consumption, dye fixation efficiency, and defect reduction. A recent study demonstrates that adopting low-liquor ratio dyeing and foam dyeing can significantly reduce water and energy usage, and decreasing effluent load [42]. Moreover, the use of enzyme-based pre-treatment instead of conventional alkaline scouring enhances dye uptake while reducing chemical waste [48]. Auto dispenser and AI-driven monitoring systems enable real-time tracking of dye exhaustion rates, ensuring optimal dye utilization and minimizing re-dyeing needs [43]. Plasma and ultrasonic-assisted dyeing methods also improve fixation efficiency, reducing dye run-off into wastewater [5,44]. Waste in garment manufacturing can be reduced by implementing marker efficiency optimization and fabric utilization techniques during the cutting process. Additionally, adopting lean production systems and digital sample development can minimize excess inventory and sample-related waste [45,46,47,48].

Reuse is another option to manage the textile waste. Reuse extends the life of textiles by transferring them to new owners through resale, donation, renting, or upcycling, with or without modification [34,35,55]. Reusing spinning waste, such as carding waste, comber noil, and sliver waste, promotes sustainability by reducing reliance on virgin raw material and minimizing environmental impact in the textile industry [34,37]. One common approach is to blend these waste fibers with virgin cotton or synthetic fibers to produce new yarns in the same spinning system, particularly for coarse yarn fabric applications. Open-end spinning technology also allows the conversion of these waste fibers into yarns that are suitable for denim, towels, and upholstery. Additionally, nonwoven textiles, such as automotive interiors, insulation, and industrial wipes, benefit from the reuse of spinning waste [32,33]. Spinning waste has applications in fiber-reinforced composites and specialized paper products. In weaving, excess warp and weft yarns, as well as selvage waste, can be repurposed for handloom weaving, handicraft, decorative trims, or even braided into ropes and mats. Factories and artisans often reuse discarded fabric pieces for patchwork, quilting, or accessory-making, minimizing waste [40,49]. Dyeing and printing waste, including misprinted fabrics and off-cut materials, can be repurposed by different methods. Misprinted fabrics can be over-dyed to create unique designs, while leftover dyed fabrics can be converted into smaller items such as scarves, pouches, or home décor [51]. Large-scale textile companies and fashion brands increasingly incorporate upcycling techniques to use defective or excess printed materials in new product lines [47,50,51].

In textile manufacturing, wastewater reclamation and reuse are increasingly adopted to address water scarcity and reduce environmental impact. Recycled water is used for such processes as dyeing, washing, and cooling, thus conserving fresh water and promote sustainable production [53].

3.3.2. Recycling or Recovering

Textile recycling involves processing pre- or post-consumer textile waste into new textile or non-textile products. Textile recycling can be broadly classified into open-loop and closed-loop systems [33,35,54]. In open-loop recycling, waste materials are converted into different products, often of lower quality than the original. This method does not restore the waste textile to its initial form but allows repurposing for other industries, such as turning old textiles into insulation, carpets, industrial padding, or PET bottles, which can be converted into polyester fiber [55]. Closed-loop recycling, by contrast, preserves the original material properties, allowing the recycled product to serve as a direct substitute for virgin material [56]. For example, polyester garments can be chemically recycled into polyester fibers for new clothing, reducing the environmental impact of textile production. Fabric recycling technologies can be classified as mechanical, chemical, biological, and thermal recovery [57,58,59].

Physical Methods for Recycling or Recovering

Physical methods of recycling consist of mechanical and thermo-mechanical recycling of textile waste. Mechanical recycling involves shredding textiles into fibers for re-spinning into yarns or creating nonwoven materials [60]. Mechanical recycling preserves almost all fiber properties; however, fiber length is reduced due to the tearing or cutting of the fabric. The color of recycled fibers depends on the classification or sorting of the raw materials. If color sorting is performed effectively, re-dyeing can be avoided. Mechanical recycling is mainly used for natural textile fabrics. It is recommended for monofiber fabrics like cotton and wool. It is rarely used for viscose due to its fiber structure and lower yield [61,62]. Table 2 presents the different physical recycling processes and technologies used for various types of textile waste.

Various thermomechanical pretreatment techniques can be employed to convert textile waste into bioenergy, including mechanical comminution, extrusion, and ultrasonic treatment. The process begins with mechanical action, where textile waste is reduced to smaller particles through milling, chipping, or grinding [63]. This process improves material handling and increases the surface area, thereby enhancing the efficiency of subsequent bioenergy conversion. The extrusion method exposes textile waste to high temperatures (above 300 °C), shearing, and mixing, resulting in changes to the polymer’s physical structure. This method requires single or compatible polymers, as mixed fibers may weaken the material or cause process failure. Dyes, finishes, and mixed colors may reduce quality of the recycled fiber; thus, proper sorting is crucial. This method suits heat-resistant synthetics like polyester and polyamide [64,65]. However, with each recycling cycle, the polymer undergoes slight degradation, leading to a gradual decline in fiber quality over time. It is also used for cellulosic fibers in which cellulosic fiber waste, such as cotton, linen, or viscose, cannot be directly converted by standard thermo-mechanical recycling, as these fibers do not melt like synthetic polymers. Instead, when exposed to high temperatures, cellulosic fibers tend to burn or degrade and are primarily utilized for energy recovery. To recover energy from cellulosic waste, thermal processes such as combustion, pyrolysis, or gasification can be used [66]. Combustion burns fibers to generate heat and electricity, while pyrolysis heats them in absence of oxygen to produce bio-oil, syngas, and biochar [65,67]. Ultrasonic treatment employs high-frequency sound waves to disrupt hydrogen bonds in crystalline cellulose, enhancing polymer breakdown conversion efficiency [63,64,65,66].

Chemical Methods for Recycling or Recovering

Chemical recycling involves break down textile materials into their original monomers or chemicals, which can then be reused to produce new fibers or other materials [11]. Chemical processes such as acid, alkali, peroxide, and ozone treatments are commonly used [67,68]. In these processes, for example, polymer depolymerization breaks down synthetic polymers such as PET and nylon into their monomers (e.g., terephthalic acid, ethylene glycol) for reuse. Another example involves cellulose dissolution, which dissolves cotton or other cellulosic fibers in solvents (e.g., ionic liquids, Lyocell process) to convert them into new fibers without harmful by-products [69]. Table 3 presents a summary of various efforts over the past 20 years to process different textile materials, highlighting technologies used and the challenges across different substrates.

One common method involves dissolving cotton in selected solvents to recover either chemically modified or pure cellulosic fibers. This approach allows the recycled cotton to be used as feedstock to produce recycled man-made cellulosic fibers [70]. The dissolution process can be achieved through different processes, such as the Lyocell process, alkali/urea, or ionic liquid processes. The Lyocell process has gained attention in recent years as a promising alternative to traditional viscose technology. It offers a safer and more sustainable approach to regenerating cellulosic fibers by eliminating hazardous by-products typically generated in other processes, such as carbon disulfide (CS₂), hydrogen disulfide (H₂S), and heavy metals [71,72]. This makes it an environmentally friendly option for the chemical recycling of cotton fabrics. Moreover, the ionic liquid process is also being actively researched and developed, presenting another promising method for the chemical recovery of cellulosic fibers [73].

Chemical recycling of polyester textiles involves breaking down PET into monomers or oligomers, primarily through solvolysis using solvents such as methanol, ethylene glycol, or amines in processes like methanolysis, glycolysis, and aminolysis. Pyrolysis is less commonly used, as it generates CO₂ and CO. Recycling PET, particularly from cotton–PET blends, remains challenging due to fiber degradation and difficulties in the sorting step [74].

Chemical recycling of wool waste is not widely practiced; however, small-scale recovery of wool keratin for applications such as biomaterials and adhesives has been demonstrated [76]. While regenerating wool keratin into fibers has not been successful, keratin extraction is reported. Wool fibers consist of approximately 82% keratin, which is rich in cysteine (10–15%) and forms strong disulphide bonds that significantly limit solubility [83,84].

Combination recycling refers to the strategic integration of mechanical with chemical or biological recycling methods to maximize the recovery and reuse of textile materials, thereby supporting a circular economy. This approach effectively breaks down complex fiber blends, such as polyester, cotton, spandex, and nylon, into their monomer components, facilitating the recycling of textiles that are challenging to process mechanically. Post-consumer mixed textile waste using microwave-assisted glycolysis over a ZnO catalyst, followed by solvent dissolution, is an example of combination recycling [66,77].

Biological Recycling/ Recovering

Biological recycling involves the decomposition of textiles by microorganisms through such processes as composting and anaerobic digestion [11,12,43,89]. It also includes enzymatic depolymerization of textile polymers into monomers and subsequent fermentation to convert the feedstock into valuable products. Textile waste consists of both biodegradable and non-biodegradable waste materials. Biodegradable textile waste typically decomposes within two weeks to six months, depending on its composition and level of microbial activity [90,91]. Biodegradable textile waste (natural fiber, regenerated fiber, natural dyes, etc) is highly susceptible to microbial degradation. Cotton, composed mostly of cellulose, is vulnerable to microbial attack by such species as Bacillus, Fusarium, Clostridium, Myrothecium, Sporocytophaga, and Memnoniella, which are able to hydrolyze and oxidize cellulose. Fungi are also highly efficient in breaking down cotton-based textiles [57,92]. Polyamide (nylon) fibers can be degraded using laccase-mediator and protease enzymes. Bacteria such as Flavobacterium and Pseudomonas species have been reported to degrade nylon oligomers, while lignolytic fungi oxidases can depolymerize polyamide [88,89,95].

Enzymatic hydrolysis is an effective biological method for textile degradation. Enzymes such as cellulase, protease, amylase, and lipase can hydrolyze textile materials, breaking them down into monomeric forms based on their constituents [92,93,94,95]. Enzymatic saccharification is particularly important in recycling cotton-based textile waste, offering an eco-friendly alternative to conventional methods. For protein-based fibers, such as wool, keratinolytic enzymes can convert keratin into useful nutrients such as carbon, sulfur, and nitrogen [93,96,97]. In synthetic textiles, PET hydrolysis has attracted growing interest, particularly with the discovery that certain bacteria can utilize PET as a carbon source. Enzymes such as PETase and MHETase have been genetically engineered to improve the efficiency of PET degradation [57,98]. Another study showed that cutinases from Cunninghamella echinulata can degrade polyester films, while lipases from Candida cylindracea and Pseudomonas species target various polyesters [83,88,99]. Oxidative mechanisms attributed to laccase enzymes from Phanerochaete chrysosporium have been shown to break down polypropylene, demonstrating the potential of enzymatic treatment of this resistant plastic [99]. Other microbial communities found in the gut microbiota of mealworms have demonstrated their ability to degrade polystyrene, thereby promising biological insights to manage persistent polymer waste through natural processes [100]. In addition to the above, biological methods provide an eco-friendly approach to dye removal; however, they can generate toxic intermediates, involve high operational costs, and require extended retention time [101].

3.4. Value-Added Products from Textile Waste

3.4.1. Textile Products from Pre- and Post-Consumer Waste

Recovery of textile products from in-process and post-consumer waste offers a sustainable, resource-efficient approach to minimize textile waste [71]. Discarded spinning waste, yarns, fabric clippings, and other remnants are commonly reprocessed into valuable fibers or yarns through mechanical recycling [103,104]. Research demonstrates that in-process waste, especially yarn waste, has superior fiber length, uniformity, and a higher percentage of floating fibers compared to post-consumer waste such as rag and garment waste [62,105]. Open-end spinning is an effective technique for converting waste fibers into new yarns [106]. Selecting the right blend ratios and utilizing soft waste components, such as liker-in waste fibers, can enhance yarn performance while reducing variability [36,37]. The resulting yarns can be used in high-quality textile applications, including denim, chino fabrics, and towels, offering a viable alternative to virgin fiber-based products [107]. This approach reduces costs and supports sustainable textile practices by extending the life cycle of materials [108]. Mechanical recycling methods, such as shredding, opening, and carding, are preferably applied to natural and single-composition waste, including post-consumer garments made of 100% cotton or 100% wool. Before garments are shredded, non-textile components like zippers and buttons are removed [104,105,106]. The fibers are then disentangled and aligned through a carding process, after which they can be spun into new yarn. Mechanically recycled fibers tend to be shorter than virgin fibers, necessitating blending with longer virgin fibers to maintain quality and durability [37,108]. It can be used in open-end spinning without the need for blending. Table 4 summarizes various research studies focus on converting textile waste into both conventional and technical textile products.

In addition to mechanical recycling, textile products can also be derived through chemical recycling of textile waste, which enables the regeneration of textile fibers. For instance, cotton waste can be pulped and dissolved, such as with NMMO, then respun into regenerated fibers like Lyocell. Furthermore, pretreatment with phosphoric acid has demonstrated 100% polyester and 79.2% for glucose [73,79,81,82].

3.4.2. Bioethanol Production from Textile Waste

The production of ethanol from food crops raises concerns about food scarcity and threats to biodiversity [35]. Second-generation bioethanol utilizes lignocellulosic feedstocks to mitigates concerns related to food scarcity and biodiversity [7,116]. Bioconverting textile waste into bioethanol supports a sustainable solution for waste management and renewable energy. The process generally includes pretreatment, enzymatic hydrolysis, fermentation, commonly using Saccharomyces cerevisiae, and distillation for ethanol recovery. Textile waste, especially cotton-based materials, is rich in cellulose (96%), a polysaccharide that can be converted into fermentable sugars [117]. However, the complex structure of cellulose, along with the presence of dyes and other additives in textile waste, necessitates pretreatment to enhance enzymatic accessibility [119]. The primary challenge, however, is breaking the hydrogen bonds between glucan chains to reduce crystallinity and enhance accessibility. An investigation showed an ethanol yield of 92.5% from cotton gin residue using an over-lime steam-explosion process, resulting in 191 L (50 gal) per ton [119]. The study considered dilute sulfuric acid pretreatment at 180 °C followed by yeast fermentation. Another study 120] reported ethanol production from cotton linters and jeans textiles using enzymatic hydrolysis and fermentation with Saccharomyces cerevisiae, achieving a 99% yield following NaOH pretreatment. Figure 8 illustrates an approach to valorizing textile waste by converting plant-based fibers and sizing agents into fuel-grade ethanol. The process includes pretreatment, physical, chemical, or biological, to release fermentable sugars, followed by microbial fermentation and ethanol purification [119,120,121].

Researchers have successfully separated cellulose from cotton-polyester blends using N-methylmorpholine-N-oxide (NMMO), yielding 48–50 g ethanol/g for cotton and viscose fibers [121,122]. Alkaline pretreatment of polyester-cotton blends with 12% sodium hydroxide for one hour enhances glucose and ethanol yields, while simultaneously recovering polyester fibers with near-original properties, enabling both bioethanol production and fiber reuse [58,85,122]. Additionally, researchers have explored alternative pretreatment methods, including ammonia-based processes, high-temperature treatments, ozone pretreatment, and microwave-assisted techniques [66,78]. Another study demonstrates that mercerization pretreatment significantly enhances ethanol yield, approximately three times higher than that achieved with corona-pretreated cotton waste [116,120]. Different types of garments yield varying amounts of ethanol; for instance, waste white T-shirts subjected to separate hydrolysis and fermentation produced the highest yield at 83.5% after 24 hours. White T-shirts generate 537 mL/kg of ethanol, outperforming materials like rice straw, pine, and oak. Yellow T-shirts, linen, denim, and white towels follow in yield. This demonstrates strong potential for white T-shirts as a low-cost bioethanol source [11,78,122]. Waste jeans composed of cotton and polyester have also been successfully utilized for bioenergy production following sodium carbonate (Na₂CO₃) pretreatment. Optimum results are obtained using 0.5 M Na₂CO₃ at 150 °C, enhancing both polyester breakdown and cellulose digestibility. This led to high yields of methane (up to 361.1 mL/g VS), glucose (up to 88.0%), and ethanol (up to 69.4%). The process proved effective with minimal cellulose loss, establishing waste jeans as a viable feedstock for both biogas and ethanol production [145]. Cottonseed oil (CSO) processed via heterogeneous catalysis has demonstrated the highest conversion rate of 98%, while cotton-seed cake (CSC) and waste cotton cooking oil (WCCO) also show excellent yields of 96.5% and 96.0%, respectively [123,124].

3.4.3. Biogas Production from Textile Waste

Biogas production from textile waste reveals a sustainable approach to managing textile-based biowaste while generating renewable energy [123]. The anaerobic digestion (AD) is a well-known process for this purpose, which involves the breakdown of organic textile waste materials by microbial action in the absence of oxygen, producing biogas primarily composed of methane (CH₄) and carbon dioxide (CO₂) [117,125]. Figure 9 illustrates a sustainable, integrated approach for treating textile waste and wastewater treatment, encompassing four main stages: hydrolysis, acidogenesis, acetogenesis, and methanogenesis [126]. It has been shown that textile-based biowaste, such as cotton stalks, cotton seed hulls, and cotton oil cakes, can yield substantial amounts of biogas at optimized conditions that significantly enhance methane production [123]. Moreover, co-digestion with organic materials, such as swine manure or cow dung, has been found to improve biogas yield, making the process more efficient [123,126]. Textile wastewater, originating from such processes involving yarns, fabrics, dyeing, and fiber production, contains different types of pollutants such as synthetic compounds, carbohydrates, proteins, lipids, and humic substances [128,129]. These pollutants can be treated by two technologies, namely microbial fuel cells (MFCs) and anaerobic digestion (AD) [126]. MFCs utilize electroactive bacteria to oxidize organic matter, thereby degrading the pollutant removal and produce energy [130]. Anaerobic digestion decomposes organic contaminants, such as cellulose, lipids, and proteins, into biogas, primarily methane (CH₄) [131], which can be converted into electricity or utilized directly as a combustion fuel. The residual digestate can be separated into solid and liquid components. The solid fraction undergoes gasification or pyrolysis, resulting in production of syngas (a mixture of H₂ and CO₂) and char. Syngas can be further refined into cleaner fuels, supporting the model’s energy recovery goals [128]. The liquid fraction from digestate is treated through algal water treatment systems. Microalgae play a crucial role in absorbing nutrients, removing dyes and heavy metals, and improving water quality. This process produces treated water suitable for reuse in agricultural or fiber farming applications [131]. Moreover, the algal biomass obtained from this process is a valuable source of bio-based products, including bioplastics, natural fertilizers or soil conditioners, animal feed additives, biopolymers, natural dyes and pigments, and ingredients for cosmetics [132,133].

Pretreatment of textile waste is essential for enhancing biogas production, as untreated fibers are difficult to digest. Techniques such as chemical (NaOH, ammonia, NMMO), enzymatic, and ultrasonic treatments improve the material’s biodegradability. Pretreated cotton/polyester blends and cotton linters have significantly demonstrated higher methane production compared to untreated samples [74,129]. It has been shown that desizing wastewater is also suitable for biogas production [128]. Thermophilic conditions have been shown to significantly enhance biogas yields, especially from medical cotton waste, increasing methane production up to 92% compared to mesophilic conditions [130,131]. A comprehensive study on biogas production from various textile-based biowastes demonstrates significant variations in methane yields, largely dependent on substrate composition and pretreatment methods. Bleached cotton linter achieved the highest methane yield at 449 mL/g volatile solids (VS), followed by viscose/polyester and cotton/polyester textile fabrics at 415 mL/g VS. In contrast, cotton plant residues such as stalks and bolls yielded 246 mL/g VS, while cottonseed hulls produced only 86 mL/g [130,132].

3.4.4. Bioelectricity from Textile Waste

Microbial fuel cells (MFCs) generate electricity by utilizing microorganisms that oxidize organic and inorganic substrates under anaerobic conditions, simultaneously treating textile wastewater (Figure 9) [130]. An MFC has anode and cathode chambers separated by an ion-exchange membrane, where microorganisms degrade organic matter in the anodic chamber [135]. The efficiency of MFC depends on microbial activity, substrate type, electron transfer mechanisms, dye concentration, and electrode materials. As illustrated in Figure 9, MFC represents a bio-electrochemical system that can treat textile wastewater while simultaneously generating electricity. Materials such as carbohydrates, synthetic compounds, and humic substances from the textile effluent serve as substrates for electroactive microbes within the MFC. These microbes, located in the anode chamber, oxidize the organic matter, releasing electrons that flow through an external circuit to the cathode chamber, producing an electric current [136]. Different types of textile waste have been treated using various reactor configurations, yielding diverse power densities. Various studies demonstrated the ability of single-chamber MFCs to handle wastewater containing azo dyes and other synthetic colorants, resulted in different levels of power output. In contrast, dual-chamber systems treating such materials as polylactic acid-based textile waste or certain acidic dyes have revealed varying current densities and voltage outputs [136,137]. Worth mentioning that the power densities depend on several factors, such as the type of dyes, reactor design, and operating conditions.

3.4.5. Composting of Textile Waste

Composting is an environmentally friendly method to break down organic textile waste, such as cotton, converting it into nutrient-rich soil supplements. This bio-oxidative process, driven by microorganisms, significantly reduces waste volume [138]. Vermicomposting, using earthworms, enhances soil fertility beyond conventional composting by increasing bacterial density and humus quality. Studies have explored composting willow waste from ginning factories, typically discarded in landfills. When mixing with cow dung slurry, enzymes, and microbial solutions, organic textile waste can decompose within 20 days [123,126]. Earthworms then transform it into high-quality compost, promoting plant growth. Cotton gin waste is also composted due to hygiene risks in direct reuse [139]. It has also been reported that over 90% of oyster mushroom growers using cotton waste substrates [126,140]. Composting of textile waste mixed with green and paper waste was evaluated for biosafety, showing non-phytotoxic compost at up to 60% textile input. All composts met heavy metal standards, indicating composting as a safe and effective method for textile waste valorization [138,139,140].

3.4.6. Textile Waste for the Value-Added Chemicals and Bioplastics

Value-added chemicals are compounds derived from various waste materials or biomass and transformed into products with higher economic value and broader applications [121]. Several methods, including chemical recycling, enzymatic hydrolysis, pyrolysis, anaerobic digestion, and solvent dissolution, are employed to convert waste into these valuable chemicals (Table 3). Cellulosic waste like cotton, jute, and flax is converted to glucose, then to lactic acid (LA) via enzymatic hydrolysis and fermentation, used in bioplastics (PLA) and pharmaceuticals. Glucose extracted from textile waste can also be converted into sorbitol through acid hydrolysis and hydrogenation, used in biodegradable polymers and sweeteners. Polyester waste can be converted into EG and TPA [94]. Succinic acid can be produced from cotton textile waste using a fibrous bed bioreactor through microbial fermentation. It is used in detergents, surfactants, food, and pharmaceuticals. It also helps make tetrahydrofuran, 1,4-butanediol, and succinate polymers [116]. Silk waste contains sericin and fibroin, which can be extracted using hot water or alkali for use in biomedical and cosmetic formulations. Wool waste yields keratin and amino acids through enzymatic or alkaline digestion, useful in fertilizers and biodegradable materials [95]. Jute waste provides lignin and furfural via acid hydrolysis or pyrolysis, which are used in biofuel additives, resins, and carbon materials [34]. Dye sludge or effluent produces methane and volatile fatty acids (VFAs) through anaerobic digestion, generating bioelectricity and heating fuel [135,137,141].

Several studies have shown that low molecular weight cellulose sources like cotton linters, MCC, and CNCs can be effectively converted into bioplastics [141,142]. Bioplastic films have been produced from cellulose derivatives such as cellulose acetate by hot-pressing. In another study, low-quality cotton fibers are dissolved in a DMAc/LiCl system and processed into strong, transparent, and flexible films through regeneration and hot-pressing. These films showed improved mechanical and surface properties. In another study, flax waste was catalytically converted into valuable aromatic hydrocarbons using USY zeolite, with optimized Si/Al ratios enhancing furan yields [143,144].

3.4.7. Textile Waste for Value-Added Material in the Construction, Furniture, and Geoengineering Industry

Textile waste fibers provide sustainable solutions in construction, furniture, and geotechnical engineering by improving mechanical properties, reducing environmental impact, and offering cost-effective alternatives. Researcher [145] shows that recycled textile waste can be used to design sustainable and eco-friendly furniture.

Further researchers demonstrate that denim textile waste can be converted into 3D needle-punched composites and high-density fiberboards for furniture use [115,146].

Textile waste is increasingly used as a secondary raw material in fiber-reinforced composites, enhancing compressive strength, flexural resistance, and crack mitigation [129]. Incorporating 1% recovered cotton fibers from denim into fiber concrete increases compressive strength by 40% and flexural strength by 7%. Recycled nylon fibers from fishing nets also improve tensile strength and toughness in cement mortars [147,148,149]. Chemical treatments, such as maleic anhydride modification, enhance fiber-polymer adhesion, improving mechanical performance. Additionally, cotton/polyester blends demonstrate improved structural properties in heat compression molded composites [112,113,114,150]. Textile waste also strengthens pavements, columns, bridge decks, and airport runways. Lightweight bricks incorporating cotton waste and limestone powder exhibit mechanical properties comparable to conventional bricks [150,151]. Fiber-reinforced soil composites with polypropylene, polyester, and nylon improve shear strength and load-deformation behavior. Longer fibers enhance soil strength by increasing internal friction. Mixing synthetic fibers with fly ash or cement boosts compressive strength and durability. Natural fibers also improve stress-strain responses in stabilized clay soils [151,152]. The moisture level within the soil also plays a vital role, as it affects cohesion and the soil’s ability to support loads when reinforced with fibers [153]. The addition of shredded polypropylene fibers boosts both triaxial compressive and residual strength. Randomly distributed fibers (0.6–1%) improve soil performance under traffic loads, and combining them with fly ash boosts stress-strain behavior further [154]. Fiber reinforcement improves slope stability by boosting load-bearing capacity and reducing soil volume, cost, and time. Synthetic fibers like polypropylene and polyester, mixed with clay and admixtures (fly ash, lime), enhance UCS and STS to a certain limit [155]. Geotextile made from recycled nonwoven supports erosion control and slope stabilization. Polypropylene fiber-reinforced sand improves bearing capacity, stiffness, and ductility. It performs comparably to traditional geotextiles in retaining walls and slopes [156,157].

3.5. Role of AI in Waste Textile Waste Management

During bibliometric analysis, it is found that in the last five years, Artificial Intelligence (AI) and Machine Learning (ML) have been playing an important role in textile waste management [16,17]. These technologies are applied in three ways: data-driven waste reduction, intelligent sorting, and valorization process with quality prediction [159]. AI uses data-driven methods to track product life cycles and identify high-waste stages. Machine learning predicts waste before processing, helping optimize raw materials and machine settings, reducing fiber waste in spinning, fabric waste in weaving, and garment waste in manufacturing. They can also reduce waste by predicting quality issues and defects [160]. In air-jet spinning, AI techniques help improve airflow dynamics by analyzing factors within the spinning nozzle, leading to better nozzle designs and reduced fiber loss [161]. Further, AI combined with digital twin technology reduces waste in garment manufacturing by analyzing parameters like marker efficiency, fabric utilization, and cut order planning to optimize cutting layouts and predict material loss. Digital twin also helps [163].

AI is also showing a significant role in the sorting of textile waste. Traditional textile waste sorting methods are predominantly manual, labor-intensive, and prone to human error, thereby limiting both the efficiency and scalability of recycling operations [15,16]. Researchers found that AI-enabled systems use computer vision, spectral imaging, and machine learning to automate textile sorting. These systems identify natural vs. synthetic fibers, separate blends, and detect fabric wear or contamination [164,165]. Further autonomous sorting pipelines integrate robotics, spectral imaging, and AI-based classification models to enhance sorting accuracy and efficiency [163]. Smart recycle bins use AI classifiers and sensor technology to automatically segregate waste into categories like plastic, metal, paper, and organic material. Image recognition and real-time sensor input ensure efficient recycling and reduce human effort [166]. An infrared spectroscopy-based classification method using PCA, CVA, and k-NN algorithms has demonstrated 100% accuracy in identifying synthetic and natural textile fibers, offering a promising pathway toward fully automated textile sorting. This approach significantly enhances the efficiency of post-consumer textile waste recycling [167]. The Eco-Detect system utilizes the YOLOv7 algorithm combined with IoT technologies to automate real-time waste sorting with high speed and accuracy [168]. The EcoSort-AI system developed offers a smart waste management solution that uses convolutional neural networks (CNNs), IoT-enabled bins, and machine learning to automate waste classification and improve recycling efficiency [166,169]. By integrating Raman spectroscopy with machine learning and deep learning algorithms, textile waste can be sorted at a rate of 1 item per second with over 95% precision, effectively categorizing complex fiber combinations and significantly enhancing recycling quality within a circular economy framework. Using online near-infrared (NIR) spectroscopy and a convolutional neural network (CNN), researchers achieved over 95% accuracy in identifying and sorting 13 types of waste textiles with a processing speed of less than 2 seconds per item, enabling fast, non-destructive, and intelligent textile recycling [170]. The integration of an AI-enhanced vision system using YOLOv8 with a PLC-controlled conveyor system significantly improves waste sorting efficiency, achieving up to 91% accuracy for plastic bottles and an overall mean average precision (mAP50) of 86%, demonstrating strong potential for scalable, real-time, and sustainable industrial recycling applications [171]. AI-powered recycling turns plastic waste into useful products through smart, automated processes [172].

Beyond sorting and tracking, AI is increasingly involved in the development of advanced recycling technologies. AI helps in assessing the quality of textile waste and forecasting the potential of recycled products. In chemical recycling, for example, AI aids in optimizing reaction conditions for depolymerizing polyester and cotton into monomers such as terephthalic acid and ethylene glycol [173]. In bioconversion processes, textile waste is transformed into bio-based chemicals like bioethanol, sorbitol, and lactic acid through enzymatic hydrolysis and microbial fermentation, with AI modeling reaction pathways and predicting outputs under varying conditions [174]. The research presents a data-driven circular economy framework that integrates advanced AI and IoT technologies to enable waste-to-energy systems and sustainable material recovery in the Industry 4.0 era [174]. Moreover, AI-powered digital platforms are facilitating the development of closed-loop supply chains, wherein post-consumer garments are traced, collected, and converted into new textiles or alternative products [174,175].

4. Conclusions

The textile industry is economically crucial, but it also causes significant environmental pollution. Waste management is increasingly seen as both an environmental necessity and an opportunity for value creation. Bibliometric analysis shows that over the past decade, there has been a surge in global scholarly and industrial interest in transforming textile waste management and valorization through methods such as mechanical and chemical recycling, thermal recovery, and biotechnological methods. China leads in research output, followed by India and Turkey, with strong contributions also coming from the U.S., Spain, and the U.K. Emerging economies like Pakistan and Malaysia show growing involvement. Notably, cellulosic fibers like cotton, bast fibers, and rayon have been successfully converted into regenerated fibers or bio-based products, whereas synthetic fibers such as polyester are increasingly being depolymerized into monomers like ethylene glycol and terephthalic acid through chemical recycling techniques. Moreover, emerging biorefinery models integrate thermochemical and enzymatic processes to yield high-value compounds, including lactic acid and glucose, ethanol, and biogas from diverse textile waste streams. AI and machine learning tools like PCA, CVA, and k-NN enable accurate sorting of synthetic and natural fibers. Technologies such as Eco-Detect, EcoSort-AI, and spectroscopy systems enhance recycling efficiency and support circular economy efforts. Additionally, textile waste is increasingly being repurposed in fiber-reinforced material for the construction industry.