Production Of Synthetic Fibers Research Articles

Calcite Added PP Fiber Production

Synthetic fiber production is one of the basic applications of the modern textile industry. However, increasing environmental concerns and sustainability requirements are forcing the sector to produce more environmentally friendly and innovative solutions. In this study, calcium carbonate (CaCO₃) additive was used in the production of polypropylene (PP) staple fiber. CaCO₃, a natural and renewable mineral, was added as a raw material to polypropylene production in order to ensure environmental sustainability, reduce production costs and improve fiber properties. Within the research scope of the project, it was decided to use CaCO₃ with high purity, special coating on the surface and stable particle size distribution. Using the compound production line, homogenous spreading of calcium carbonate in powder form into the PP matrix is one of the preliminary studies. During the fiber production trials, CaCO₃ was observed to improve processability, optimise extrusion pressure and prevent residue formation in spinnerets. In terms of fiber properties, positive effects such as opacity, static electrification resistance, textural improvements and industrial performance enhancement were noted. In addition, the cost advantage of the additive by reducing the use of TiO₂ and reducing the carbon footprint are important findings. The thermal conductivity-enhancing effect of calcium carbonate decreases the processing temperature range, resulting in energy savings in production processes. Moreover, thanks to its compatibility with recycling processes, polypropylene nonwovens containing CaCO₃ can be reprocessed without loss of performance and improve homogeneity. These properties increase industrial functionality and sustainability while reducing the environmental impact of polypropylene products. In the project outputs carried out as Telasis Tekstil, it is seen that the use of calcium carbonate in polypropylene fiber production offers an innovative approach to reducing environmental impacts and improving product quality. The study can inspire manufacturers and researchers to develop sustainable textile solutions.

Extraction of Natural-Based Raw Materials Towards the Production of Sustainable Man-Made Organic Fibres.

Bioresources have been gaining popularity due to their abundance, renewability, and recyclability. Nevertheless, given their diverse composition and complex hierarchical structures, these bio-based sources must be carefully processed to effectively extract valuable raw polymeric materials suitable for producing man-made organic fibres. This review will first highlight the most relevant bio-based sources, with a particular focus on promising unconventional biomass sources (terrestrial vegetables, aquatic vegetables, fungi, and insects), as well as agroforestry and industrial biowaste (food, paper/wood, and textile). For each source, typical applications and the biopolymers usually extracted will also be outlined. Furthermore, acknowledging the challenging lignocellulosic structure and composition of these sources, an overview of conventional and emerging pre-treatments and extraction methods, namely physical, chemical, physicochemical, and biological methodologies, will also be presented. Additionally, this review aims to explore the applications of the compounds obtained in the production of man-made organic fibres (MMOFs). A brief description of their evolution and their distinct properties will be described, as well as the most prominent commercial MMOFs currently available. Ultimately, this review concludes with future perspectives concerning the pursuit of greener and sustainable polymeric sources, as well as effective extraction processes. The potential and main challenges of implementing these sources in the production of alternative man-made organic fibres for diverse applications will also be highlighted.

Environmental Impact Assessment of Natural Vs Synthetic Fiber Reinforcement in Polymer Composites

Abstract: This research examines the environmental influences of natural and synthetic fiber reinforcement in polymer composites specifically the aspects of greenhouse gas emissions, energy demands, biodegradability, and mechanical characteristics. Some organic fibers like jute, hemp, and flax are more eco-friendly than synthetic fiber because during the process of growing, they need less energy and they also absorb carbon dioxide. On the other hand, synthetic products such as glass and carbon fibre, which exhibit superior mechanical properties are disadvantageous in this context as they are energyintensive in manufacture and difficult to dispose of sustainably. The study looks at the use of water and land in the production of natural fibers vs. synthetic fibers and can compare major trade-offs in terms of resource consumption. Overall, both investigations indicate appropriate uses for each fiber sort, enabling purchasers to make educated decisions in a scope of business sectors. In addition, the paper stresses the need for the creation of eco-friendly processes for synthetic fiber production together with the improvement of the performance characteristics of natural fibers for high-performance applications. In light of the above findings, there is, therefore, the need to consider environmental constraints and the desired performance characteristic when selecting the material to be incorporated into polymer composite

Fibrous microplastics in the environment: Sources, occurrence, impacts, and mitigation strategies

Fibrous microplastics (FMPs), a unique class of microplastics, are increasingly recognized as a significant environmental threat due to their ubiquitous presence and potential risks to ecological and human health. This review provides a comprehensive overview of FMPs, including their sources, prevalence in various environmental media, and potential impacts. FMPs, which can be found in over 90 % of certain environmental samples, originate from a diverse range of sources, including synthetic textiles, landfill waste, industrial emissions, and atmospheric deposition. These persistent pollutants pose a threat to both terrestrial and marine ecosystems. Their insidious presence can lead to ingestion by organisms, potentially disrupting ecosystems and posing risks to human health. Addressing the challenge of FMPs requires a multi-faceted approach. Reducing the production and use of synthetic fibers, implementing effective waste management practices, and developing new technologies to remove FMPs from wastewater and the broader environment are all crucial components of the solution. However, further research is essential to fully understand the long-term implications of FMPs on ecosystems and human health, laying the foundation for the development of robust and effective mitigation strategies.

Highly Efficient Production of Furfural from Corncob by Barley Hull Biochar-Based Solid Acid in Cyclopentyl Methyl Ether–Water System

Furfural, an important biobased compound, can be synthesized through the chemocatalytic conversion of D-xylose and hemicelluloses from lignocellulose. It has widespread applications in the production of valuable furans, additives, resins, rubbers, synthetic fibers, polymers, plastics, biofuels, and pharmaceuticals. By using barley hulls (BHs) as biobased support, a heterogeneous biochar Sn-NUS-BH catalyst was created to transform corncob into furfural in cyclopentyl methyl ether–H2O. Sn-NUS-BH had a fibrous structure with voids, a large comparative area, and a large pore volume, which resulted in more catalytic active sites. Through the characterization of the physical and chemical properties of Sn-NUS-BH, it was observed that the Sn-NUS-BH had tin dioxide (Lewis acid sites) and a sulfonic acid group (Brønsted acid sites). This chemocatalyst had good thermostability. At 170 °C for 20 min, Sn-NUS-BH (3.6 wt%) was applied to transform 75 g/L of corncob with ZnCl2 (50 mM) to generate furfural (80.5% yield) in cyclopentyl methyl ether–H2O (2:1, v/v). This sustainable catalytic process shows great promise in the transformation of lignocellulose to furfural using biochar-based chemical catalysts.

Bamboo belts with variable fiber cell angles for winding applications: Development of a novel manufacturing technique and assessment of performance feasibility

In response to the environmental impacts of synthetic fiber production and disposal, coupled with limitations in the existing continuous processing methods for plant fibers, this study proposed a novel manufacturing approach for preparing wide and continuous bamboo winding belts. The current application scenarios of bamboo belt winding products are limited because the reinforcement orientation cannot be optimized due to the inherent stiffness of bamboo belts, and the variety of bamboo belt types is limited. This study employed two representative types of bamboo belts: bamboo slivers and thin bamboo veneers, which had varying cross-sectional aspect ratios. Verification demonstrated that this method enabled the production of bamboo winding products with any reinforcement orientations ranging from 0 radians to π radians. This addressed the challenge of optimizing reinforcement orientation in bamboo winding products and was anticipated to broaden the application of this method to other winding units with unidirectional reinforcement. Additionally, the performance feasibility of the two bamboo winding belts prepared using this method was evaluated in terms of microstructure, surface wettability, and mechanical properties. The bamboo slivers and thin bamboo veneers, with their rigid-flexible structure, hydrophilicity, and non-catastrophic fracture characteristics, enhanced their winding potential. These wide, continuous, and rigid-flexible features of the bamboo winding belts held promise for their expanded applications in bamboo winding products, thus promoting sustainable and environmentally friendly manufacturing practices.

SYNTHESIS AND PROPERTIES OF MAGNETIC COMPOSITE Fe3O4 STABILIZED BY POLYMERS FOR CATALYTIC OXIDATION OF AROMATIC HYDROCARBONS

The present study is aimed at creating catalytic systems based on magnetite (Fe3O4) stabilized by polymers (polyvinylpyrrolidone (PVP) and chitosan), for liquid-phase oxidation of organic compounds with gaseous oxygen in order to obtain oxygen-containing compounds that can be used in the production of dyes, synthetic fibers, drugs, and many other petrochemical products. Magnetic composites of Fe3O4 stabilized by PVP and chitosan were synthesized by the coprecipitation method. The prepared magnetic composites were studied by physicochemical analysis methods. It was found that surface stabilization with polymers leads to a decrease in the size of magnetite nanocrystallites in nanocomposites. The sizes of the studied composites are less than ∼ 10 nm. Mössbauer spectra of the obtained Fe3O4, Fe3O4/PVP, and Fe3O4/chitosan composite catalysts showed the presence of trivalent iron ions in a tetrahedral environment and the presence of Fe2+ and Fe3+ in an octahedral environment, as well as a doublet spectrum. The possibilities of using magnetite-based composite catalysts for heterogeneous liquid-phase oxidation of para-xylene with oxygen are considered. Based on the analysis of the IR spectra of the final reaction samples, the presence of CH bonds in the aromatic ring and C=C double bonds, as well as valence vibrations of the C=O group of carbonyl compounds and vibrations of the bonds of hydroxyl groups was established. It is shown that the main products of the oxidation reaction of p-xylene are p-toluyl aldehyde and dibutyl phthalate, which can be widely used for basic organic synthesis. The authors concluded that the magnetic composite of the Fe3O4/PVP composition can be used to produce oxygen-containing compounds, in particular, toluyl aldehyde and dibutyl phthalate.

Occupational health risk for workers in the production of synthetic polyacrylonitrile fibers

The high proportion of workers in the chemical industry working in hazardous working conditions and the justification of measures to preserve their health are an urgent task in the field of protecting the health of the working population, however, aspects of the formation of occupational risks in the production of chemical fibers remain insufficiently studied. The article presents the results of prospective cohort comprehensive studies of working conditions and health status of 137 workers in the production of polyacrylonitrile fibers. The factors of the working environment (chemical, microclimate, noise), the severity and intensity of the labor process, the first identified and chronic non-infectious morbidity for 2017–2021 were studied. It has been established that workers work under the influence of a complex of factors harmful to their health, including chemicals of hazard classes 1–4 (acrylonitrile, methyl acryate, hydrocyanide, sulfuric acid, caustic alkalis, ethylene glycol, isopropyl alcohol), industrial noise, physical and neuro-emotional overloads, the levels of which, to varying degrees, exceed the hygienic standards, forming harmful working conditions (classes 3.1–3.4). In the structure of the accumulated chronic morbidity of workers, the leading ranking places belonged to diseases of the musculoskeletal system and connective tissue (24.3 %), the circulatory system (16.04 %), and the genitourinary system (15.0 %). As a result of the assessment of cause-and-effect relationships of health disorders with work, the production conditionality of diseases of the musculoskeletal system and connective tissue, represented by dorsalgia of various levels, of an average degree (RR = 1.893; EF = 47.183 %; CI = 1.192–3.007) was established. Quantitative assessment of group occupational risk corresponded to the category of «high risk» (4.780 × 10–2), indicating the need to reduce it to an acceptable level. The limitation of the study was the study of occupational risk factors for health disorders among employees of one enterprise. The results obtained were used to develop measures to reduce occupational health risks for workers in the production of synthetic polyacrylonitrile fibers.

Enhancing mechanical properties of natural fiber composites: a study on the effects of fiber loading and filler addition

In this research, we conducted an extensive analysis of two distinct composite materials: NWBF/EP (nonwoven banana fiber/epoxy) and NWBF/EP/WNP (nonwoven banana fiber/epoxy with walnut powder). These composites were meticulously engineered, utilizing epoxy as the matrix, nonwoven banana fiber as the primary reinforcement, and walnut powder as the secondary reinforcement. Our investigation unveiled that the NWBF/EP/WNP hybrid composite exhibits superior mechanical properties in comparison to the NWBF/EP composite. Notably, the BW4 hybrid composite demonstrated a substantial increase in tensile strength, reaching an impressive 76.7 MPa. This enhancement underscores the potential for augmenting composite stiffness by elevating the WNP ratio up to a specific threshold, though exceeding this threshold leads to a reduction in epoxy resin content. Furthermore, our study revealed substantial improvements in flexural strength as WNP was introduced, with a noteworthy 5.8% rise at a 5% weight percent WNP loading. The pinnacle of flexural strength, 43.6 MPa, was achieved at a 20% weight percent loading. Impact toughness also displayed significant improvements, with the highest impact strength (5.2 J) observed in BW3. This highlights the potential for enhancing the toughness of the hybrid composite within a defined WNP weight percent range. We also gained valuable insights into hardness, void fraction, and the influence of walnut powder. The addition of walnut powder increased void fraction, reduced density, and enhanced various mechanical properties. Our evaluation of wear performance emphasized the pivotal role of factors such as sliding velocity, fiber content, sliding distance, and normal load. In conclusion, this research not only elucidates the mechanical advantages of the NWBF/WNP/epoxy hybrid composite but also offers critical insights for potential applications. The findings underscore the potential of these hybrid composites to serve as sustainable and competitive alternatives to synthetic fiber products in a range of engineering and manufacturing contexts.

Hemicellulose-rich paper-grade pulp as raw material for regenerated fibres in an ionic liquid-based process

Hemicellulose-rich pulp raw materials are avoided in the production of man-made cellulosic textile fibres due to hemicellulose reactivity with the currently used industrial solvent systems. Incorporation of hemicelluloses in regenerated fibres could, however, increase the share of used wood biomass and thus improve the environmental footprint of regenerated fibre products. Superbase ionic liquids have shown potential in dissolving and regenerating all the major wood polymers i.e. cellulose, hemicellulose and lignin into regenerated products. In this work, regenerated fibres were spun from hemicellulose-rich softwood and eucalyptus paper-grade pulps and eucalyptus dissolving pulp using a superbase ionic liquid [mTBNH][OAc]. Before dissolution and spinning, intrinsic viscosities of the paper-grade pulps were adjusted either enzymatically or by using a mild acid-treatment to improve dope rheology for dry-jet wet spinning. In fibre spinning, hemicellulose was found to regenerate in high yield and the obtained regenerated fibres had high dry tenacities (5.3 to 15 cN/dtex). The best mechanical properties were measured from fibres with high hemicellulose content (17.3% (w/w)). Pulp pretreatment was found to be critical for achieving good mechanical properties. Acid-pretreatment, which modified both cellulose and hemicellulose, yielded regenerated fibres with better mechanical properties compared to an enzyme-pretreatment which did not alter the hemicellulose structure. Removal of hemicellulose substituents and hydrolysis of hemicellulose backbone in acid-pretreatment may be the key to improved mechanical properties in hemicellulose-containing regenerated fibres. Enzymatic peeling and imaging with a xylan-specific monoclonal antibody (CCRC-M138) suggest that hemicelluloses were enriched to the outermost layers of the regenerated fibres.

Microplastics in the Taiwan Strait and adjacent sea: Spatial variations and lateral transport

This study investigates the distribution, structural properties, and potential impacts of oceanic processes on microplastics (MPs) in the Taiwan Strait (TWS) and surrounding seas. With an average of 174 particles/m3, the MP abundance in surface seawater ranged from 84 to 389 particles/m3. MP abundance ranged from 16 to 382 particles/kg in sediments, with a median of 121 particles/kg. Fragment and fiber were the two most frequently detected shapes. These MPs were found to be composed primarily of carbon and oxygen elements at 70–90% levels using energy-dispersive X-ray spectroscopy. Additionally, several examples had trace levels of metallic components. Black was the color that MPs saw the most often out of all the hues. The two main types of polymers are polyester and rayon, and their production is influenced by home sewage discharge and synthetic fiber production. The main routes of MP transport were land source input, riverine input, and oceanic currents. This study showed that salinity affects the distribution of MPs, with high-salinity seawater serving to saturate their presence. On the other hand, upwelling raises MP concentrations by bringing nutrients from the deep to the surface. Furthermore, it has been discovered that the dilution of the Pearl River plume increases the MP prevalence in the region. The South China Sea Warm Current had the highest lateral MPs transport flux (2.1 × 1014 particles/y), which was followed by the Taiwan Strait Current area (1.0 × 1014 particles/y) and the Guangdong coastal areas (8.6 × 1013 particles/y). In sediments, the MP prevalence was inversely correlated with particle size. Flocculation processes probably made it easier for MPs to travel down the water column and deposit themselves on the aquatic substrate. Although the relationship between MPs, total organic carbon, and total organic nitrogen was not correlated, a favorable trend showed that MPs may discreetly contribute to carbon storage in coastal sediment.

Modification of Polyester Properties through Functionalization with PVA

Due to the growing demand of the textile market, the production of synthetic fibers like polyester (PET), has been increasing compared to any other existing fiber group. However, this type of fiber has its own disadvantages, the main one being its hydrophobic nature. To improve its properties, it was sought to develop a chemical functionalization. This process consisted of three steps, the first one being the cleaning of the polyester with hydrochloric acid, followed by a subsequent hydrolysis of the textile substrate in an alkaline medium in the presence of sodium hydroxide. The last phase, that concerns the textile substrate functionalization with poly (vinyl alcohol), more commonly known as PVA, was made by a process of exhaustion at different pH values (3, 6, and 10), followed by a curing, which allowed the formation of bonds between the PVA and the polyester fibers and consequently improve polyester properties, namely the hydrophilicity, presenting a contact angle of 0º. This process of functionalization of the polyester with PVA at acidic pH, led to very promising results since a significant improvement of its properties was obtained. The functionalized and original polyester samples were further characterized through the application of several techniques, such as SEM, FTIR-ATR and differential scanning calorimetry DSC. These characterization techniques allowed to prove that the textile substrates were effectively modified. It can be concluded that, properties such as, contact angle, tensile strength, air permeability, coefficient of friction and water vapor permeability, were substantially improved by the functionalization of the polyester fabric with PVA.

Physico-chemical properties of functionally adhesive spider silk nanofibres.

Currently, synthetic fibre production focuses primarily on high performance materials. For high performance fibrous materials, such as silks, this involves interpreting the structure-function relationship and downsizing to a smaller scale to then harness those properties within synthetic products. Spiders create an array of fibres that range in size from the micrometre to nanometre scale. At about 20 nm diameter spider cribellate silk, the smallest of these silks, is too small to contain any of the typical secondary protein structures of other spider silks, let alone a hierarchical skin-core-type structure. Here, we performed a multitude of investigations to elucidate the structure of cribellate spider silk. These confirmed our hypothesis that, unlike all other types of spider silk, it has a disordered molecular structure. Alanine and glycine, the two amino acids predominantly found in other spider silks, were much less abundant and did not form the usual α-helices and β-sheet secondary structural arrangements. Correspondingly, we characterized the cribellate silk nanofibre to be very compliant. This characterization matches its function as a dry adhesive within the capture threads of cribellate spiders. Our results imply that at extremely small scales there may be a limit reached below which a silk will lose its structural, but not functional, integrity. Nano-sized fibres, such as cribellate silk, thus offer a new opportunity for inspiring the creation of novel scaled-down functional adhesives and nano meta-materials.

An Overview of Chemical Additives on (Micro)Plastic Fibers: Occurrence, Release, and Health Risks

Plastic fibers are ubiquitous in daily life with additives incorporated to improve their performance. Only a few restrictions exist for a paucity of common additives, while most of the additives used in textile industry have not been clearly regulated with threshold limits. The production of synthetic fibers, which can shed fibrous microplastics easily (< 5 mm) through mechanical abrasion and weathering, is increasing annually. These fibrous microplastics have become the main composition of microplastics in the environment. This review focuses on additives on synthetic fibers; we summarized the detection methods of additives, compared concentrations of different additive types (plasticizers, flame retardants, antioxidants, and surfactants) on (micro)plastic fibers, and analyzed their release and exposure pathways to environment and human beings. Our prediction shows that the amounts of predominant additives (phthalates, organophosphate esters, bisphenols, per- and polyfluoroalkyl substances, and nonylphenol ethoxylates) released from clothing microplastic fibers (MFs) are estimated to reach 35, 10, 553, 0.4, and 568 ton/year to water worldwide, respectively; and 119, 35, 1911, 1.4, and 1965 ton/year to air, respectively. Human exposure to MF additives via inhalation is estimated to be up to 4.5–6440 µg/person annually for the above five additives, and via ingestion 0.1–204 µg/person. Notably, the release of additives from face masks is nonnegligible that annual human exposure to phthalates, organophosphate esters, per- and polyfluoroalkyl substances from masks via inhalation is approximately 491–1820 µg/person. This review helps understand the environmental fate and potential risks of released additives from (micro)plastic fibers, with a view to providing a basis for future research and policy designation of textile additives.Graphical Abstract

Synthesis and analytical characterization of N-methylated derivatives of α-tocopheramine and their oxidation products

N-Methylated derivatives of α-tocopheramine, which have preliminarily been shown to have good performance as stabilizers of cellulose solutions in ionic liquids for production of cellulosic manmade fibers, have not been accessible in sufficient amounts by green syntheses. In this study, the N-methyl-, N,N-dimethyl-, and N,N,N-trimethylammonium derivatives of α-tocopheramine were synthesized and fully analytically characterized. The procedures used dimethyl carbonate as solvent and methylating agent as well as aluminum oxide as the reusable catalyst. Care was taken to ensure that the procedures conformed to green chemistry principles and were easily upscalable.Graphical abstract

Reclaiming the Value of Cotton Waste Textiles: A New Improved Method to Recycle Cotton Waste Textiles via Acid Hydrolysis

The fashion industry is becoming one of the largest emitters worldwide due to its high consumption of raw materials, its effluents, and the fact that every garment will eventually contribute to the vast amount of waste being incinerated or accumulating in landfills. Although fiber-to-fiber recycling processes are being developed, the mechanical properties of the textile fibers are typically degraded with each such recycle. Thus, tertiary recycling alternatives where textiles are depolymerized to convert them into valuable products are needed to provide end-of-life alternatives and to achieve circularity in the fashion industry. We have developed a method whereby cotton waste textiles are depolymerized to form a glucose solution, using sulfuric acid as the sole catalyst, with a high yield (&gt;70%). The glucose solution produced in this process has a high concentration (&gt;100 g/L), which reduces the purification cost and makes the process industrially relevant. This method can be applied regardless of the quality of the fibers and could therefore process other cellulosic fibers such as viscose. The glucose produced could subsequently be fermented into butanediol or caprolactam, precursors for the production of synthetic textile fibers, thus retaining the value of the waste textiles within the textile value chain.

Banana Fiber: Environmental Friendly Fabric: A way to Health and Wealth

Abstract: Banana is one of the rhizomatous plants and currently growing 129 countries around the world. It is the fourth most important global food crop. Different parts of banana trees serve different needs, including fruits as food sources, leaves as food wrapping, and stems for fiber and paper pulp. Historically, banana stems had been used as a source of fiber with the earliest evidence around the 13thcentury. But its popularity was faded after other convenient fibers such as cotton and silk were made available. As fiber industry has been developing to increase production efficiency, new fibers were then developed to effectively respond the consumer’s need, including the production of man-made fibers using petroleum to optimize the fiber properties. The chemical use inevitably causes contamination in every environmental medias - water, soil and air, which directly affects human well-being and environment

Polyester-Polyvinylalcohol Hydrophilization Strategies

Poly (ethylene terephthalate) (PET), also commonly called as polyester, is the most widely used polymer for the production of synthetic fibres over the past fifty years. The frequent use of this PET is due to its high mechanical strength combined with other properties such as the resistance to chemical products, stretching and abrasion. The fibre’s hydrophobicity also impacts the difficulty of cleaning these materials [1, 2]. Previous works shows that treatment with concentrated NaOH solutions can greatly improve hydrophilicity of PET fibre [1, 2, 3, 4]. However a significant decrease of mechanical properties takes place during this process. In this work, chemical strategies to counteract this negative effect and further increase the hydrophilicity of PET fibre’s has been tested. In particular, the effect of polyvinyl alcohol (PVA) and N, N ́-dimethylol-4, 5-dihydroxyethyleneurea (DMDHEU) chemically modified resin in the functionalization of saponified PET was carefully analysed. The treated fabrics were characterized by scanning electron microscopy (SEM), contact angle, ATR-FTIR spectroscopy and differential scanning calorimetry (DSC). When the best process conditions were considered for PVA-DMDHEU application, the modified PET presented a contact angle of 33.9o, stain release grade of 4 and a 45.6% increase in its mechanical properties when compared to saponified PET.

Dyeing and finishing wastewater treatment in China: State of the art and perspective

China has the largest textile production and export in the world, with a massive amount of wastewater and related pollutants releasing. With an increasing concern to improve water quality, dyeing and finishing wastewater (DFW) requires better disposal or reclamation. In this review, the characteristics of wastewater in different natural and synthetic fiber production processes as well as the origins of their specific pollutants such as aniline, absorbable organic halogens (AOX), sulfide, hexavalent chromium and antimony were summarized. The discharge standards for DFW in China, have undergone complex evolution processes, which were discussed including the current standard, the revision detail and the one to be implemented. Furthermore, the current status of pollutant reduction in the textile industry, covering cleaner production and wastewater treatment, was targeted, in particular the state of the art of specific pollutant removal technologies and their feasibility of application for DFW treatment. Also, reclamation systems based on wastewater discharge characteristics and reclaimed water quality requirements were reviewed. Overall, the systematic solution of source reduction of wastewater and contaminants, coupled with subsequent treatment and recycling, is crucial for the sustainable development of the textile industry.

THE PROCESS OF PYROLYSIS AS AN ALTERNATIVE TO CONVENTIONAL ENERGY SOURCES TYPES AND BENEFITS

As one of the fastest developing countries, Uzbekistan expected to face certain problems on the sphere of natural resources used for energy production due to increasing high demand. Alternatives to conventional energy resources should be proposed and developed before running out of minerals totally. Team of researchers suggests the process of pyrolysis as a tool to get an alternative energy resource. The target pyrolysis product is some gas rich in unsaturated hydrocarbons: ethylene, propylene, butadiene. On the basis of these hydrocarbons, polymers are obtained for the production of plastics, synthetic fibers, synthetic rubbers and other important products.