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Composite materials based on renewable agricultural and biomass feedstocks are increasingly utilized as these products significantly offset the use of fossil fuels and reduce greenhouse gas emissions in comparison with conventional petroleum-based materials. However, the inclusion of natural fibers in polymers introduces several challenges, such as excess water absorption and poor thermal properties, which need to be overcome to produce materials with comparable properties to the conventional composite materials. Instead of using rather expensive chemical and physical modification methods to eliminate these aforementioned challenges, a new trend of utilizing waste, residues, and process by-products in natural fiber-polymer composites (NFPCs) as additives or reinforcements may bring considerable enhancements in the properties of NFPCs in a sustainable and resilient manner. In this paper, the effects of waste materials, residues or process by-products of multiple types on NFPCs are critically reviewed and their potential as NFPC constituents is evaluated. [ABSTRACT FROM AUTHOR]

Waste based activated biochar was used to manufacture wood/polypropylene biocomposites. The biochar used had no surface functional groups, however, possessed high surface area (335 m 2 /g). Therefore, it was hypothesised that less than usual amount (3–5 wt%) of compatibiliser (maleic anhydride) could be used, to reduce production costs, while maintaining similar mechanical and flammability properties of the biocomposite. The biocomposites were characterised mechanically through tension, flexural, impact, and micro–hardness tests. The flammability and thermal behaviours were determined using cone calorimetry and thermogravimetry, respectively. Infrared spectroscopy and X–ray diffraction were also employed to comprehend the chemical changes occurring in the biocomposites. It was found that the amount of compatibiliser could be reduced to 1 wt% (from 3 wt%) without compromising on the mechanical performance (especially, tensile strength/modulus, impact strength, and micro–hardness) and flammability properties of the biocomposites. Electron microscopy revealed that the lack of compatibiliser in the biocomposites was compensated by well–dispersed biochar particles whose pores were infiltrated by the polymer causing a mechanical interlocking. In general, addition of biochar improved the mechanical and fire performance of the biocomposites compared to the neat polymer. Reduction of compatibiliser to 1 wt% from 3 wt% in conjunction with biochar saves ∼18% of the biocomposite production costs. [ABSTRACT FROM AUTHOR]

In this study, the application of hydrocolloid and fiber industry wastes and their transformation in biochar and biocomposite as biosorbents for emerging pollutants effective removal was carried out. Initially, the adsorption ability of six different wastes was ascertained in single and competitive removal of sulfamethoxazole (SMX) and methylparaben (MePa). Among them, fiber extraction process wastes presented the best result attaining maximum uptakes with removal levels up to 23 and 48% of MePa and SMX, respectively. The adsorption capacity was enhanced by fiber waste biochar preparation at 500 °C and 30 min under nitrogen atmosphere, and improved by the preparation of laccase-biocomposites, achieving maximum uptakes more than ten-fold the obtained using raw material. The simultaneous removal of the pollutants by the biocomposite followed a pseudo-second order kinetic and resulted in maximum uptakes of 24.06 and 23.15 mg/g for SMX and MePa, respectively. Finally, raw material and laccase-biocomposite behaviours were simulated by homogeneous surface diffusion model. Previously, the isotherms were studied fitting well to Freundlich model. The obtained results remarked the feasibility of laccase-biocomposite in which reactive groups incorporation on the biochar surface could be responsible for facilitating the pollutants removal from the aquatic environment. Image 1 • Lime and lemon waste (LL) could be used as biosorbent at low PPCPs concentration. • SMX and MePa sorption intensity of LL was enhanced by biochar preparation (Bc). • Biocomposite made by laccase adsorption on Bc (BcL) modified its surface increasing the uptake. • BcL improved the uptake values more than 10-fold the maximum level of LL. • Upscaling fixed bed adsorption column was modelled using LL and BcL in flow system. [ABSTRACT FROM AUTHOR]