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In this study, the polar root extract of Cyperus scariosusR.Br. was used for the biogenic synthesis of ZnO NPs. The results of this study show that ZnO NPs have a spherical structure with an average size of 85.4 nm. The synthesized catalysts were tested for their photocatalytic activity by degrading methyl orange and methylene blue under sunlight. Improved degradation efficiencies of 79.44% and 84.92% were achieved within 120 min. ZnO NPs exhibited strong antibacterial activity against both Gram-positive Listeria monocytogenes(18 mm) and Staphylococcus epidermidis(20 mm) and Gram-negative strains of Escherichia coli(16 mm) and Bordetella bronchiseptica(14 mm), as shown by the inhibition zones, which were comparable to the positive control (ceftriaxone) but larger than the plant root extract. ZnO NPs showed high antioxidant activity, as a ferric-reducing antioxidant power assay value of 66.29 µg (AAE µg·mL−1) and a DPPH value of 57.44 µg (AAE µg·mL−1) were obtained at a concentration of 500 µL, which was higher than those of the C. scariosusroot extract. Quantification of the total phenolic and flavonoid content yielded values of 57.63 µg (GAE µg·mL−1) and 70.59 µg (QCE µg·mL−1), respectively. At a concentration of 500 μL (1 mg·mL−1), the tested nanoparticles (NPs) showed a greater anti-inflammatory effect (84.12%) compared to the root extract of C. scariosus(34.39%). Overall, our findings highlight the versatile properties of green synthesized ZnO NPs and demonstrate their potential for environmental remediation and antimicrobial formulations, as well as promising candidates for further investigation in biomedical fields such as drug delivery and therapy.

Biogenic calcium carbonate (CaCO3) has attracted great attention in multiple applications. This study investigates the influence of different calcination temperatures (200–1000 °C) on the morphology and the structure of snail shells waste. The different chemical compounds obtained were characterized by scanning electron microscope (SEM), energy dispersive X-ray analyzer (EDXS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy (Raman). The identified particles for raw and calcined SSP at 200 °C were aragonite polymorphs, calcite for 400–600 °C and calcium oxide (CaO) for 800–1000 °C. The endothermic decomposition of the CaCO3phase to CaO occurs in the temperature range of 668–870 °C. The transformation takes along with a loss of about 40% of the initial weight of the sample due to the CO2release. Ca–OH bond was revealed in FT-IR spectra at calcination ≥ 700 °C. It was caused by the reaction of CaO with H2O in atmospheric air. The preparation of CaO from snail shells waste as the primary source is environmentally sustainable. Snail shells based CaO can potentially be exploited for various applications, especially for catalyst, wastewater treatment and biomedical.

Herein, we investigate how to improve the hydrochar yield via hydrothermal carbonization process, focusing on the use of almond shells as a carbon resource. We have employed various modeling techniques, including response surface methodology, artificial neural networks, support vector machines and XGBoost, to determine the optimal conditions for maximizing hydrochar yield. The results highlight the excellent performance of the ANN and XGBoost models, with high R² values and lower RMSE values, while the SVM model offers insights into the interactions between the factors. The choice of modeling method depends on the specific nature of the problem and accuracy requirements. In summary, this study contributes to a better understanding of HTC processes and opens the way to further optimization of hydrochar performance, with significant practical implications in the energy and environmental fields. It also highlights the importance of further research to explore more modeling techniques.