Environmental pollution and health hazards from distillery wastewater and treatment approaches to combat the environmental threats: A review.

The textile sector has been an important part of Bangladesh’s (BD) economy over the past few decades. In Bangladesh, the textile sector currently has an export value of nearly 28 billion USD per year which contributes about 82% of the country’s total export earnings. It is projected that the annual ready-made garment (RMG) export value will be about 50 billion USD per year by 2021. However, the growth of Bangladeshi RMG sector is associated with different environmental issues, mostly caused by wastewater generated by textile industries. Textile industries consume high volumes of water per unit fabric for processing, which cause depletion of ground water levels at a high rate. In addition, in many cases textile effluents are discharged into rivers or wetlands without proper treatment. Untreated textile effluent can contaminate groundwater and waterbodies, reduce dissolved oxygen in water and affect aquatic ecosystems which may indirectly cause climate change. Improving conventional technology, adopting cleaner production (CP) options, the reusing and recycling of treated water may reduce water consumption, effluent volume and water stresses, and may help preserving aquatic ecosystems. However, additional investments, lack of technological knowhow, and awareness are factors limiting the adoption of cleaner production options. In order to take effective measures for future improvement it is important to develop a nationwide wastewater impact tracking system. In this study, a material balance approach has been developed to characterize the trend of pollution impacts (2011–2021) associated with the textile dyeing industries of Bangladesh. It is estimated that in 2016 textile industries in Bangladesh produced about 1.80 million metric tons of fabric, which generated around 217 million m3 of wastewater (2016) containing a wide range of pollutants. It is projected that wastewater production will reach 349 million m3 by 2021 if the textile industries continue using conventional dyeing practices. Gradual adoption of improved technology and cleaner production options could reduce wastewater volume by around 23% by 2021. This projection will help policy makers to take necessary mitigation measures for treatment and pollution management. This analysis will also provide a baseline scenario and open new opportunities for textile engineers and environmentalists to develop innovative technologies for textile dyeing and effluent treatment.

Evaluation of present and future wastewater impacts of textile dyeing industries in Bangladesh

Developments in polyester composite materials – An in-depth review on natural fibres and nano fillers

In the contemporary world, natural fibers reinforced polymer composite (NFRPC) materials are of great interest owing to their eco-friendly nature, lightweight, life-cycle superiority, biodegradability, low cost, noble mechanical properties. NFRPCs are widely applied in various engineering applications and this research field is continuously developing. However, the researchers are facing numerous challenges regarding the developments and applications of NFPRCs due to the inherent characteristics of natural fibers (NFs). These challenges include quality of the fiber, thermal stability, water absorption capacity, and incompatibility with the polymer matrices. Ecological and economic concerns are animating new research in the field of NFRPCs. Furthermore, considerable research is carried out to improve the performance of NFRPCs in recent years. This review highlights some of the important breakthroughs associated with the NFRPCs in terms of sustainability, eco-friendliness, and economic perspective. It also includes hybridization of NFs with synthetic fibers which is a highly effective way of improving the mechanical properties of NFRPCs along with some chemical treatment procedures. This review also elucidates the significance of using numerical models for NFRPCs. Finally, conclusions and recommendations are drawn to assist the researchers with future research directions.

Natural fiber reinforced composites: Sustainable materials for emerging applications

There has been much effort to provide eco-friendly and biodegradable materials for the next generation of composite products owing to global environmental concerns and increased awareness of renewable green resources. This review article uniquely highlights the use of green composites from natural fiber, particularly with regard to the development and characterization of chitosan, natural-fiber-reinforced chitosan biopolymer, chitosan blends, and chitosan nanocomposites. Natural fiber composites have a number of advantages such as durability, low cost, low weight, high specific strength, non-abrasiveness, equitably good mechanical properties, environmental friendliness, and biodegradability. Findings revealed that chitosan is a natural fiber that falls to the animal fiber category. As it has a biomaterial form, chitosan can be presented as hydrogels, sponges, film, and porous membrane. There are different processing methods in the preparation of chitosan composites such as solution and solvent casting, dipping and spray coating, freeze casting and drying, layer-by-layer preparation, and extrusion. It was also reported that the developed chitosan-based composites possess high thermal stability, as well as good chemical and physical properties. In these regards, chitosan-based “green” composites have wide applicability and potential in the industry of biomedicine, cosmetology, papermaking, wastewater treatment, agriculture, and pharmaceuticals.

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Natural-Fiber-Reinforced Chitosan, Chitosan Blends and Their Nanocomposites for Various Advanced Applications

Composite materials reinforced with biofibers and nanomaterials are becoming considerably popular, especially for their light weight, strength, exceptional stiffness, flexural rigidity, damping property, longevity, corrosion, biodegradability, antibacterial, and fire-resistant properties. Beside the traditional thermoplastic and thermosetting polymers, nanoparticles are also receiving attention in terms of their potential to improve the functionality and mechanical performances of biocomposites. These remarkable characteristics have made nanobiocomposite materials convenient to apply in aerospace, mechanical, construction, automotive, marine, medical, packaging, and furniture industries, through providing environmental sustainability. Nanoparticles (TiO2, carbon nanotube, rGO, ZnO, and SiO2) are easily compatible with other ingredients (matrix polymer and biofibers) and can thus form nanobiocomposites. Nanobiocomposites are exhibiting a higher market volume with the expansion of new technology and green approaches for utilizing biofibers. The performances of nanobiocomposites depend on the manufacturing processes, types of biofibers used, and the matrix polymer (resin). An overview of different natural fibers (vegetable/plants), nanomaterials, biocomposites, nanobiocomposites, and manufacturing methods are discussed in the context of potential application in this review.

Potential Natural Fiber Polymeric Nanobiocomposites: A Review.

The expansion of environment-friendly materials based on natural sources increases dramatically in terms of biodegradable, recyclable, and environmental disputes throughout the world. Plant-based natural fiber, a high potential field of the reinforced polymer composite material, is considered as lightweight and economical products as they possess lower density, significant material characteristics, and extraordinary molding flexibility. The usage of plant fibers on the core structure of composite materials have drawn significant interest by the manufacturers to meet the increasing demand of the consumers for sustainable features with enhanced mechanical performances and functionalities. The plant fiber-based composites have widespread usage in construction, automotive, packaging, sports, biomedical, and defense sectors for their superior characteristics. Therefore, this critical review would demonstrate an overview regarding the background of natural fiber composites, factors influencing the composite properties, chemical interaction between the fiber and matrices, future potentiality, and marketing perspectives for triggering new research works in the field of biocomposite materials.

Comprehensive review on plant fiber-reinforced polymeric biocomposites

This paper reports a novel route for the coloration of polyester fabric with green synthesized silver nanoparticles (G-AgNPs@PET) using chitosan as a natural eco-friendly reductant. The formation of AgNPs was confirmed by UV-visible spectroscopy. The morphologies and average particles size of G-AgNPs was investigated by transmission electron microscope (TEM) analysis. The uniform deposition of G-AgNPs on the PET fabric surface was confirmed with scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The thermal properties were investigated using a thermogravimetric analyzer (TGA). The coloration and fastness properties of fabric were found to be significantly improved, a result related to the surface plasmon resonance of G-AgNPs. The antibacterial properties of fabric were also found to be excellent as more than 80% bacterial reduction was noticed even after 10 washing cycles. Overall, the proposed coating process using green nanoparticles can contribute to low-cost production of sustainable textiles.

https://www.mdpi.com/2079-4991/9/4/569/pdf

A Novel Coloration of Polyester Fabric through Green Silver Nanoparticles (G-AgNPs@PET).

The coconut (Cocos nucifera) fruits are extensively grown in tropical countries. The use of coconut husk-derived coir fiber-reinforced biocomposites is on the rise nowadays due to the constantly increasing demand for sustainable, renewable, biodegradable, and recyclable materials. Generally, the coconut husk and shells are disposed of as waste materials; however, they can be utilized as prominent raw materials for environment-friendly biocomposite production. Coir fibers are strong and stiff, which are prerequisites for coir fiber-reinforced biocomposite materials. However, as a bio-based material, the produced biocomposites have various performance characteristics because of the inhomogeneous coir material characteristics. Coir materials are reinforced with different thermoplastic, thermosetting, and cement-based materials to produce biocomposites. Coir fiber-reinforced composites provide superior mechanical, thermal, and physical properties, which make them outstanding materials as compared to synthetic fiber-reinforced composites. However, the mechanical performances of coconut fiber-reinforced composites could be enhanced by pretreating the surfaces of coir fiber. This review provides an overview of coir fiber and the associated composites along with their feasible fabrication methods and surface treatments in terms of their morphological, thermal, mechanical, and physical properties. Furthermore, this study facilitates the industrial production of coir fiber-reinforced biocomposites through the efficient utilization of coir husk-generated fibers.

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A state-of-the-art review on coir fiber-reinforced biocomposites

Herein, an approach was carried out toward in situ synthesis of chitosan-mediated silver (Ag) nanoparticles (AgNPs) on merino wool fabrics (MWFs) and its utilization as colored textile, antibacteri

K. M. Faridul Hasan

Papers

Potential Natural Fiber Polymeric Nanobiocomposites: A Review.

Comprehensive review on plant fiber-reinforced polymeric biocomposites

A Novel Coloration of Polyester Fabric through Green Silver Nanoparticles (G-AgNPs@PET).

A state-of-the-art review on coir fiber-reinforced biocomposites

Wool functionalization through AgNPs: coloration, antibacterial and wastewater treatment