Recycled Cotton Waste for Composites in Agrotech Applications

The main effort of this study was to enhance the enzymatic hydrolysis yields of cotton and viscose waste fibers via fed batch enzymatic hydrolysis. To do so, enzymes fed into slurries at two steps in fed batch mode. Also, the batch mode with the same amount of enzymes was implemented in order to be compared with the fed batch mode. The results showed that the released sugar contents from fed batch hydrolysis of cotton and viscose waste fibers were 29.0 and 32.3 g/l, respectively, but batch process released 25.0 and 30.3 g/l from cotton and viscose waste fibers, respectively, which confirms the increasing effect of fed batch process on the hydrolysis of both waste fibers. In addition, the morphological studies and enzymatic hydrolysis yields from pretreated cotton and untreated viscose waste fibers showed that alkali pretreatment for viscose waste fibers is not necessary, but has significant effect on enzymatic hydrolysis of cotton waste fibers; also, the differences in microcrystalline structures of viscose and cotton waste fibers have resulted in more enzymatic hydrolysis and then fermentation yields of viscose waste fibers. The amount of ethanol produced from cotton and viscose waste fibers were 6.9 and 8.1g/l, respectively.

In this study, linen and cotton fibers obtained from fabric waste were used as filler materials and polyethylene was used as matrix material to produce fiber reinforced polymer composites using injection molding. Use of fabric waste as filler material enables utilization of linen and cotton wastes while decreasing the amount of polyethylene used in the composites resulting in an environmentally friendly material. Prepared samples with varying content of linen and cotton wastes (5, 10 and 20 vol. %) were compared with each other and with polyethylene samples without any filler, based on their yield, tensile and fracture strengths, percent elongation and hardness values. Samples were also evaluated for their chip formation characteristics based on chip lengths at various machining speeds and examined for their visual appearance. Results indicated that linen waste fibers can be used to improve the strength of polyethylene based composites while cotton waste fibers can be utilized to enhance the elongation characteristics of the samples.

PurposeWool fiber is accepted as one of the natural and renewable sources and has been used in the apparel and textile industry since ancient times. However, wool fiber has the highest global warming potential value among conventional fibres due to its high land use and high methane gas generation. This study aimed to recycle the wool fabric wastes and also to create a mini eco-collection by using the produced yarns.Design/methodology/approachThis manuscript aimed to evaluate the fabric wastes of a woolen fabric producer company. Fabric wastes were opened with two different opening systems and fiber properties were determined. First, conventional ring yarns were produced in the company’s own spinning mill by mixing the opened fibres with the long fiber wastes of the company. In addition, opening wastes were mixed with different fibres (polyester, long wool waste, and Tencel fibres) between 25% and 70% in the short-staple yarn spinning mill and used in the production of conventional ring and OE-rotor yarns. Most of the yarns contained waste fibres at 50%. Recycled and virgin yarns were used as a weft and warp yarn and a total of 270 woven fabric samples were obtained and fabric properties were examined. Also, a fabric collection was created. A life cycle assessment (LCA) was made for one of the selected yarns.FindingsAt the end of the study, it was determined that it was possible to produce yarn and fabric samples from fiber blends containing high waste fiber ratios beyond 50%. All the woven fabric samples produced from conventional ring and OE-rotor yarns gave higher breaking, tearing and stitch slip strength values in the weft and warp direction than limit quality values of the company. In addition, abrasion resistance and WIRA steam stability properties of the fabric samples were also sufficient. Environmental analysis of the recycling of the wastes showed a possible decrease of about 9940034.3 kg CO2e per year in the global warming potential. In addition, fiber raw material expenses reduced yarn production cost about 50% in case of opened fabric waste usage. However, due to insufficient pilling resistance results, it was decided to evaluate the woven fabrics for the product groups such as shawls and blankets, where pilling resistance is less sought.Originality/valueThe original aspects of the article can be summarized under two headings. First, there are limited studies on the evaluation of wool wastes compared to cotton and polyester fibres and the number of samples examined was limited. However, this study was quite comprehensive in terms of opening type (rag and tearing), spinning systems (long and short spinning processes), fiber blends (waste 100% and blends with polyester, long wool waste and Tencel fibres) and yarn counts (coarser and finer). Recycled and virgin yarns were used as a weft and warp yarn and a total of 270 woven fabric samples were obtained using different colour combinations and weave types. All processes from fabric waste to product production were followed and evaluated. Life cycle assessment (LCA) and cost analysis was also done. The second unique aspect is that the problem of a real wool company was handled by taking the waste of the woolen company and a collection was created for the customer group of the company. Production was made under real production conditions. Therefore, this study will provide important findings to the research field about recycling, sustainability etc.

Currently, natural resources are rapidly depleting as a result of increasing construction facilities. Increasing energy consumption with increasing construction is another serious issue. In addition, many problems that threaten the environment and human health arise during the disposal and storage of waste materials obtained in different sectors. The main objective of this study is to investigate the substitution of cotton (CW), chicken feather (CFF) and stone wool waste (SWW) from pumice aggregate in the production of environmentally friendly hollow blocks. To achieve this, CW, CFF and SWW were substituted for pumice at ratios of 2.5–5–7.5–10% in mass, and hollow blocks were produced with this mixture under low pressure and vibrations in a production factory. Various characterization methods, including a size and tolerance analysis, unit volume weight test, thermal conductivity test, durability test, water absorption test and strength tests, were carried out on the samples produced. This study showed that waste fibers of chicken feather and stone wool are suitable for the production of sustainable and environmentally friendly hollow blocks that can reduce the dead load of the building, have sufficient strength, provide energy efficiency due to low thermal conductivity and have a high durability due to a low water absorption value.

To study the hydrothermal behavior of cotton fiber, the carbonization process and structural evolution of discarded or waste cotton fiber (WCF) under hydrothermal conditions were investigated using microcrystalline cellulose (MCC), and glucose was used as a model compound. Results showed that high temperature was beneficial for the hydrolysis of discarded cotton fiber, and the yield of sugar was 4.5%, which was lower than that of MCC (6.51%). WCF and MCC were carbonized at 240–~260°C and 220–~240°C, respectively, whereas the carbonization temperature of glucose was lower than 220°C. The C/O ratios of WCF and glucose hydrothermal products were 5.79 and 5.85, respectively. The three kinds of hydrothermal carbonization products had similar crystal structures and oxygen-containing functional groups. The carbonized products of WCF contained many irregular particles, while the main products of glucose carbonization were 0.5-mm-sized carbon microspheres (CMSs). Results showed that glucose was an important intermediate in WCF carbonization and that there were two main pathways of hydrothermal carbonization of cotton fibers: some cotton fibers were completely hydrolyzed into glucose accompanied by nucleation and then the growth of CMSs. For the other part, the glucose ring of the oligosaccharide, formed by the incomplete hydrolysis of cotton fibers under hydrothermal conditions of high temperature and pressure, breaks and then forms particulate matter.

For a sustainable environment and to tackle the pollution problem, industrial wastes can be used in concrete composite materials. This is especially beneficial in places prone to earth quack and lower temperature. In this study, five different types of waste fibres such as polyester waste, rubber waste, rock wool waste, glass fibre waste and coconut fibre waste were used as an additive in 0.5% 1%, and 1.5% by mass in concrete mix. Seismic performance related properties of the samples were examined through evaluation of compressive strength, flexural strength, impact strength, split tensile strength, and thermal conductivity. Results showed that, impact strength of the concrete significantly improved by the addition of fibre reinforcement in concrete. Split tensile strength and flexural strength were significantly reduced. Thermal conductivity was also influenced by addition of polymeric fibrous waste. Microscopic analysis was performed to examine the fractured surfaces. In order to get the optimum mix ratio, multi response optimization technique was used to determine the desired level of impact strength at an acceptable level of other properties. Rubber waste was found to be the most attractive option followed by coconut fibre waste for the seismic application of concrete. The significance and percentage contribution of each factor was obtained by Analysis of variance ANOVA (α = 0.05) and pie chart which showed that Factor A (waste fibre type) is the main contributor. Confirmatory test was done on optimized waste material and their percentage. The order preference similarity to ideal solution (TOPSIS) technique was used for developed samples to obtain solution (sample) which is closest to ideal as per given weightage and preference for the decision making. The confirmatory test gives satisfactory results with error of 6.68%. Cost of reference sample and waste rubber reinforced concrete sample was estimated, which showed that 8% higher volume was achieved with waste fibre reinforced concrete at approximately same cost as pure concrete. Concrete reinforced with recycled fibre content is potentially beneficial in terms of minimizing resource depletion and waste. The addition of polymeric fibre waste in concrete composite not only improves seismic performance related properties but also reduces the environmental pollution from waste material which has no other end use.

One of the options for improving the mechanical properties of cement composites is the use of fibre reinforcement. Nowadays, steel or polymer fibres are most frequently used for this purpose. However, given the increasingly stricter requirements related to environmental protection, one goal is to find ways of using alternative fibres of natural origin or waste fibres for which it is difficult to find other practical use. This paper focuses on one part of the development of materials which contain natural waste fibres as dispersed reinforcement in thermally insulating cement composites. The authors aimed to observe what influence the fibres have on the material’s final mechanical properties as well as thermal insulation properties. Another important factor, which was investigated, was the quotient of mechanical and thermal insulation properties. The results of this research showed that waste cellulose fibres have a considerable effect. The best compressive strength values were found in mixture M-2-BF which contained waste basalt fibres. The highest flexural strength values were reached by mixture M-3-CF-a containing cellulose fibres.

Studies have proved that the mechanical properties of concrete, suddenly is dropped off with employing waste materials as replacements. The effectiveness of fibre addition on the structural stability of concrete has been indicated in recent investigations. There are different waste aggregates and fibres as plastic, rubber tire, coconut, and other natural wastes, which have been evaluated throughout the last decades. The fibres incorporation has a substantial effect on the properties of concrete mix subjected to different loading scenarios. This paper has reviewed different types of wastes and the effect of typical fibres including Poly Ethylene Terephthalate (PET), rubber tire, and waste glass. Furthermore, waste plastic and waste rubber has been especially studied in this review. Although concretes containing PET fibre revealed a reduction in compressive strength at low fibre fractions, using PET is resulted to micro-cracking decrement and increasing flexibility and flexural strength. Finally, according to the reviews, the conventional waste fibres are well-suited to mitigated time-induced damages of concrete and waste fibres and aggregates could be a reliable replacement for concrete.

Sound absorption and thermal insulation characteristics of fabrics made of pure and crossbred sheep waste wool

Recently, the utilization of plastic composites containing natural products which are more environmentally friendly is gaining popularity. These composites can drastically reduce raw material costs while recycling natural waste products such as flocks. In this study, composites of biodegradable resins with natural products such as waste cotton fiber, recycled paper, jute fiber and granulated starch were examined experimentally for their mechanical properties.The biodegradable resins, PCL and PBS, were grafted with maleic anhydride in order to increase the in compatibility with natural products. The kneading of these biodegradable resins with natural product additives was carried out using a segmental twin screw extruder.Tensile, three-point bending and Izod impact tests were carried out. There was an improvement in the material strength characteristics in the tensile and three-point bending response to an addition of natural products in all the composites tested.The tensile and bending strength greatly dependent on the aspect ratio of the additives. Waste cotton fiber, with the highest aspect ratio showed the largest values. The Izod impact value of all composites tested however decreased.For the tensile modulus for the composites, it was shown that the complex rule of Kerner could be applied for the composites with aspect ratio under 40. In addition, it was clarified that the heat-resistance of the waste cotton composite was the greatest of all the tested composites.

This study focuses on the development and characterization of pigeon pea stalk/cotton fibers mixed with a blend ratio of 50/50, 70/30, 30/70, 60/40, 100/0 waste cotton and 0/100 waste pea stalk composites are equipped with a compression molding system. The entire composite samples are tested for acoustics, thermal and physical parameters as per the American Society for Testing and Materials standard (ASTM). The sound absorption coefficients (SAC) were measured according to ASTME1050 by an impedance tube method, and the SAC over six frequencies 125, 250, 500, 1000, 2000, and 4000 Hz were calculated. The result revealed that the composite samples that are prepared from cotton/pigeon pea waste have confirmed more than 80% of the SAC and the waste composites provided the best insulation, sound absorption, moisture absorption, and fiber properties. The effect exposed that composites materials arranged from cotton/pea stalk waste fiber have established further than 75% by the sound immersion measure and the waste 28% composites handed the fashionable Appropriation, sound immersion, humidity immersion, and fiber materials. The waste cotton/pigeon pea stalk composite samples have satisfactory moisture resistance at high humidity situations without disturbing the insulation properties.

In a world where demands for freshwater are ever-growing, wastewater remediation becomes a global concern. Especially, water, which is contaminated by oil, dyes, poses challenges to the management of water resources. The development of innovative processes for wastewater treatment is still a major obstacle. With regard to its fast removal rate and environmental compatibility, cellulose aerogel composites are recently considered as a potential contributor for water remediation. In this study, cellulose aerogel composites are fabricated using the sol–gel method from two-agroindustrial wastes: pineapple leaf fibers and cotton waste fibers in alkali-urea solution followed by freeze-drying. The prepared cellulose aerogel composites are extremely lightweight with a low density (0.053 − 0.069 g cm−3) and high porosity of nearly 95%. It is worth noting that the mechanical strength of the cellulose aerogel composites is remarkably improved with their Young’s modulus increasing by 5–9 times compared to that of the previous aerogel composites using polyvinyl alcohol as a binder. The as-synthesized aerogel composites are directly applied to adsorb cationic methylene blue and exhibit a maximum adsorption uptake of 34.01 g g−1. The methyltrimethoxysilane-coated cellulose aerogel composites also show their ability to deal with oil pollution with a maximum oil adsorption capacity of 15.8 g g−1 within only 20 s. Besides the oil removal, our developed cellulose aerogel composites have demonstrated their capability in treating dye-contaminated wastewater for the first time based on their evidenced ability to eliminate methylene blue.

In this study, the waste cotton fiber (WCF)/Bi2WO6 (BWO) composite film was prepared from BWO and WCF, which is dissolved in ionic liquid ([Amim]Cl). The samples were systematically characterized by scanning electron microscopy, X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area and UV–Vis diffuse reflection spectroscopy. The removal efficiency of rhodamine b (RhB) and methylene blue (MB) by the composite film in the dark and under visible light were investigated. The results show that the removal abilities of the composite films for RhB and MB are improved with the rise of BWO content. The removal efficiency of RhB and MB arrives at 93.73% and 97.04% under visible light irradiation when the BWO content is 1.5%, respectively. The degradation rate of MB still reaches 89% after four cycle tests. Superoxide radicals ( $$ ^{\cdot} {\text{O}}_{2}^{ - } $$ ) and holes (h+) plays a major role in the degradation and hydroxyl radicals (·OH) plays an minor role. The WCF/BWO composite film can be potentially applied in photocatalysis and wastewater treatment fields.

Thermo-physical and energy performance of building envelope modified by natural fiber through building information modelling

In this study, the porous carbonaceous microspheres (PCMs) were prepared using waste cotton fibers as precursor. The cotton fibers were first hydrolyzed and pre-carbonized through hydrothermal process, and then were heat treated at 900 °C. ZnCl2 was used to as catalyst to promote the hydrolysis of waste cotton in hydrothermal process and as pore-forming agent in subsequent heat treatment. The pore structure of the prepared PCMs were evaluated by nitrogen adsorption/desorption test, Fourier Transform Infrared spectroscopy analysis and X-ray photo-electron spectroscopy were conducted to determine its chemical properties. Scanning electron microscope was used to observe its surface morphology. Furthermore, the formation process of PCMs is investigated.