The 2020 targets for sustainable development and circular economy encourage global leaders and countries to legislate laws and policies on several critical hot topics to prevent further global warming: (1) the increased utilization of renewable electrical power (wind turbine implants, as an example); (2) waste transformation into high-added-value materials based on the European Green Deal for energy transition; and (3) material and energy recovery and circularity. Accordingly, scholars and researchers have predicted that, hopefully, installed wind power capacity is going to increase dramatically by 2050. However, our ecosystem will have to face and deal with an enormous amount of decommissioned turbine blades. The disposal of these wastes via conventional methods could not only raise the possibility of microplastic formation, but could also boost the probability of environmental issues such as air pollution, soil, water contamination, etc. Moreover, these hazards will endanger wildlife and humans. As a result, the waste management of these retired blades composed of multi-lateral composite materials through a sustainable, effective, and feasible single/or hybrid process is necessary. This review aims to summarize all of the information about turbines, introduce all the various recycling pathways used for their blades, and provide a comparative analysis of these methods as well. In addition, the paper defines the possibility of microplastic formation from this waste (especially end-of-life turbine blade scraps), points out potential risks for the Earth, and suggests actions to inhibit their build-up and to keep the environment safe.

A new hybrid fiber blend containing microfibrillated cellulose (MFC) gel and recycled carbon short fiber (RCSF) was implemented for designing fiber-reinforced cement mortars, to further improve the mechanical properties and enhance the sustainability of cement-based materials. The individual impact of single fibrous fillers as well as the synergistic effect of a hybrid fiber system (MFC + RCSF) were investigated in terms of the rheological properties, mechanical strength, and microstructure of the mortars. The results indicated that the workability of fresh mixtures slightly increased after fiber addition. The fibers incorporated alone improved the materials’ performance in different ways. The addition of RCSF led to improvements of up to 76% in flexural strength and 13% in compression strength for a fiber content of 0.75 wt.%. However, the addition of carbon fibers led to slight deteriorations in terms of porosity and water absorption. On the other hand, the use of MFC induced a less significant growth in terms of mechanical strength (+14% in flexural strength for 0.75 wt.% of cellulose) but greatly improved the microstructural quality of the mortar, significantly reducing its water permeability. Considering the optimum MFC dosage, MFC+RCSF hybrid mixtures showed positive effects on the mechanical properties and microstructure of the mortar, displaying further improvements in strength, while preserving a lower porosity and water absorption than the control mix.

Recently, environmental issues have compelled people worldwide to pursue sustainability and adopt circular economy practices across all engineering sectors, including polymer engineering and composite fabrication. A transition towards fabric-reinforced thermoplastics (FRTPs), a greener solution, has been recommended in recent years. On the other hand, utilizing recovered reinforcing phases, such as recycled carbon fiber (rCF), has attracted tremendous attention. In this framework, the aim of this research is to investigate the performance of acrylic-based FRTPs (Elium^® resin developed by Arkema). Woven virgin carbon fiber (vCF) and non-woven recycled carbon fiber (rCF) fabrics were used as reinforcement architectures for the fabrication of composites via resin infusion. The optimized formulation selected for the matrix showed flexural modulus and flexural strength of 5 GPa and 78 MPa, respectively. Composites prepared with woven vCF reached 36 GPa and 620 MPa values of flexural modulus and strength, respectively. The study of non-woven fabric is of particular interest, because the web is composed of recycled carbon fibers obtained from end-of-life (EoL) thermoset composite components. The results were promising; the flexural modulus reached 8 GPa, and the flexural strength was 113 MPa. Improvements are anticipated, especially in the parameters and conditions of the molding process.