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Microplastic fibers, also known as microfibers, are the most abundant microplastic forms found in the environment. Microfibers are released in massive numbers from textile garments during home laundering via sewage effluents and/or sludge. This review presents and discusses the importance of synthetic textile-based microfibers as a source of microplastics. Studies focused on their release during laundering were reviewed, and factors affecting microfiber release from textiles and the putative role of wastewater treatment plants (WWTPs) as a pathway of their release in the environment were examined and discussed. Moreover, potential adverse effects of microfibers on marine and aquatic biota and human health were briefly reviewed. Studies show that thousands of microfibers are released from textile garments during laundering. Different factors, such as fabric type and detergent, impact the release of microfibers. However, a relatively smaller number of available studies and often conflicting findings among studies make it harder to establish definitive trends related to important factors contributing to the release of microfibers. Even though current WWTPs are highly effective in capturing microfibers, due to the presence of a massive number of microfibers in the influent, up to billions of fibers per day are released through effluent into the environment. There is a need to establish standardized protocols and procedures that can allow meaningful comparisons among studies to be performed.

Effective dissolution of cellulosic macromolecules is the first predominant step to prepare functional bio-based materials with desirable properties. In this study, we developed an improved dissolution process using a freeze-drying pretreatment to promote the dissolution of cellulose. Rheological measurements of cellulose solutions and physicochemical characterization of regenerated cellulose films (scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis) were performed. Cellulose solution prepared from 5% microcrystalline cellulose (w:v) in the solvent exhibits a Newtonian fluid character while cellulose solutions at higher concentrations show a pseudo-plastic fluid behavior. Results from physicochemical characterization indicate that a freeze-drying pretreatment step of cellulose leads to a complete dissolution at 5% concentration while only part of cellulose is dissolved at 10% and 15% concentrations. The results obtained indicated that the use of a freeze-drying pretreatment step under mild conditions lead to a complete dissolution of cellulose at 5% concentration. The cellulose films prepared from 5% concentration exhibited desirable properties such as good optical transparency, crystallinity, and thermal stability.

Biopolymers are polymeric materials derived from biological sources. Due to their renewability, abundance, biodegradability and other unique properties such as high adsorption capabilities and ease of functionalization they have been investigated for several industrial applications including sorption. Polysaccharides especially cellulose, chitin and chitosan are important biopolymers because of their high abundance, wide distribution and low cost of production. This chapter provides an overview of properties, common processing methods, and material characterization of three commonly studied biopolymers namely cellulose, chitin and chitosan. It provides a thorough review on recent developments on utilization of cellulose, chitin, and chitosan-based materials for various sorption applications. Specifically, their application and efficiency in organic dye removal, heavy metals removal, oil and solvent spillage cleanup, and CO 2 adsorption are presented and discussed.

Synthetic dyes have become an integral part of many industries such as textiles, tannin and even food and pharmaceuticals. Industrial dye effluents from various dye utilizing industries are considered harmful to the environment and human health due to their intense color, toxicity and carcinogenic nature. To mitigate environmental and public health related issues, different techniques of dye remediation have been widely investigated. However, efficient and cost-effective methods of dye removal have not been fully established yet. This paper highlights and presents a review of recent literature on the utilization of the most widely available biopolymers, specifically, cellulose, chitin and chitosan-based products for dye removal. The focus has been limited to the three most widely explored technologies: adsorption, advanced oxidation processes and membrane filtration. Due to their high efficiency in dye removal coupled with environmental benignity, scalability, low cost and non-toxicity, biopolymer-based dye removal technologies have the potential to become sustainable alternatives for the remediation of industrial dye effluents as well as contaminated water bodies.