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The management of large amounts of eggshell waste annually produced in the world is problematic as generally this material is only disposed at landfills with odor production and microbial growth. On the contrary, significant environmental and economic advantages could be obtained transforming this biowaste into new value-added products. Eggshell biowaste was the starting material for the synthesis of hydroxyapatite by a simple and sustainable procedure and applied for the removal of Co2+ from aqueous solutions. The effects of contact time and initial metal concentration were investigated in batch experiments. Eggshell-based hydroxyapatite (ESHAP) before and after Co2+ removal was characterized by X-ray diffraction and scanning electron microscopy. The process was rapid and reached equilibrium within 80 min. The removal efficiency was in the range 70–80% which is generally higher than other waste-derived adsorbents. Adsorption of Co2+ on the surface of ESHAP particles and ion exchange with Ca2+ resulting in the formation of a Co-phosphate are the main mechanisms of the metal removal. The conversion of eggshell waste to a low-cost adsorbent for the treatment of metal contaminated waters could contribute to a more sustainable and effective management of this biowaste.

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Micro-Raman spectroscopy is applied for the study of two classes of ancient ceramic artefacts showing different features and technological background, i.e. the fine-grain Black Gloss Ware from Motya (Sicily, Italy) and the coarse-grain pottery from Khirbet al-Batrawy (Jordan). The characterization of the mineralogical composition of these ceramics allows exploring the firing conditions and the manufacturing process. In particular, μ-Raman spectroscopy permits to define the mineralogical assemblage of the bulk of both groups of ceramic samples as well as the nature of the black gloss and superficial decorations. Moreover, μ-Raman spectroscopy, allowing the identification of mineral phases in traces and describing as a consequence a more detailed mineralogical assemblage, can contribute to address issues concerning the provenance of the raw materials. The evaluation of the Raman results compared to those obtained by optical microscopy, X-ray diffraction and electron microscopy highlights that Raman spectroscopy shows a great potential in the analysis of coarse-grain and low fired ceramics, whereas it proves its limits in the analysis of fine and vitrified pottery class where the intergrowth of glass and crystalline phases provides Raman spectra not so easily interpretable.