BIO-DUST: BIO-circular 3D printable prodUctS for cultural heriTage

Every year in Italy, several thousand tonnes of eggshells, mollusc shells, fish bones and animal bones are stored as food waste (Food and Agriculture Organization of the United Nations, 2021), creating problems in their disposal. These biowastes are an important reserve of carbonate and phosphate that could be used as potential precursors in the production of useful biomaterials, limiting the exploitation of geological ones (De Angelis et al., 2017). In line with the Circular Economy Action Plan and the 12th goal of the 2030 Agenda, BIO-DUST project aims at producing a new green product starting from the recycle of food waste to be used in 3D printing. Indeed, carbonates and phosphates of geological origin are the most used fillers in the 3D printing technique called Fused Deposition Modelling (FDM) (Zárybnická et al., 2022). In a sustainable perspective, these inorganic fillers will be synthetized starting from food industry waste (Mignardi et al., 2020), consequently limiting the supply of natural resources. They will be mixed with algal-derived polysaccharides, to create safe, green, and nontoxic 3D printable biopolymers. The use of this product in the culture industry, not only as gifts in museum shops, but also for filling missing pieces of statues and to reproduce copy of artworks, will be fundamental for research, documentation, restoration and for educational purposes in an idea of wide accessibility and inclusive perspective. Reintegrating touch and other senses into the cultural experiences will have great benefits in accessibility, increasing the involvement in culture of persons with learning difficulties, children, elderly, blind or visually impaired visitors. Furthermore, a complete characterization of the new product, from the raw materials and during the whole production process, using both static and dynamic techniques as FT-IR, XRPD, SEM-EDS, TGA, NMR, will allow the evaluation of possible applications in other fields, such as engineering, medicine, food, and industries, further boosting the impact of the research. The first step of BIO-DUST project involved the collection of eggshells, mollusc shells and animal bones as raw materials from food waste. From these raw materials, inorganic additives (i.e., hydroxyapatite and biochar) were synthesized using different procedures, such as precipitation method by acid and by calcination and microwaves irradiation. Parameters such as calcination temperature and time, power and exposure time to microwaves, have been optimized in order to develop a sustainable production process. Both hydroxyapatite and biochar were characterized using the diagnostic techniques mentioned above.