The use of lignocellulosic remnants of the açaí agro-business will benefit the environment with a precursor material for biomedical applications. Nanocellulose (NC) allows the biomimetic growth of biphasic ceramics on its surface, with characteristics compatible with bone tissue, including bioactive properties and biocompatibility. In this study, the composites were obtained from açaí tegument (Euterpe Oleracea Mart.) NC using acid hydrolysis. The characterization performed by scanning electron microscopy showed the characteristic crystals of hydroxyapatite (HA) and calcium triphosphate (β-TCP) based on the results of X-ray diffraction, with the peak at 22°, showing the NC nucleation of HA and peak at 17° showing tricalcium phosphate (β-TCP). Fourier transform infrared spectroscopy confirmed the presence of O-H at 3400 cm⁻¹ and C-H at 2900 cm⁻¹, which is characteristic of cellulose; peaks were also observed at 1609 cm⁻¹, verifying the reduction in lignin content. Groups PO₄⁻³ at approximately 1070 cm⁻¹, P-OH at 910–1040 cm⁻¹, and HCO₃⁻ at 2450 cm⁻¹ confirmed the formation of HA and β-TCP. The zeta potential had a range of −11 ± 23.8 mV related to particle size, which had a range of 164.2 × 10⁻⁹–4748 × 10⁻⁹ m.

The possibility of utilizing lignocellulosic agro-industrial waste products such as cassava peel hydrolysate (CPH) as carbon sources for polyhydroxybutyrate (PHB) biosynthesis and characterization by Amazonian microalga Stigeoclonium sp. B23. was investigated. Cassava peel was hydrolyzed to reducing sugars to obtain increased glucose content with 2.56 ± 0.07 mmol/L. Prior to obtaining PHB, Stigeoclonium sp. B23 was grown in BG-11 for characterization and Z8 media for evaluation of PHB nanoparticles’ cytotoxicity in zebrafish embryos. As results, microalga produced the highest amount of dry weight of PHB with 12.16 ± 1.28 (%) in modified Z8 medium, and PHB nanoparticles exerted some toxicity on zebrafish embryos at concentrations of 6.25–100 µg/mL, increased mortality (<35%) and lethality indicators as lack of somite formation (<25%), non-detachment of tail, and lack of heartbeat (both <15%). Characterization of PHB by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), and thermogravimetry (TGA) analysis revealed the polymer obtained from CPH cultivation to be morphologically, thermally, physically, and biologically acceptable and promising for its use as a biomaterial and confirmed the structure of the polymer as PHB. The findings revealed that microalgal PHB from Stigeoclonium sp. B23 was a promising and biologically feasible new option with high commercial value, potential for biomaterial applications, and also suggested the use of cassava peel as an alternative renewable resource of carbon for PHB biosynthesis and the non-use of agro-industrial waste and dumping concerns.

The lack of suitable destinations for plastics materials can be a global environmental problem. The alternative use of materials for sustainable construction encourages the standardization of waste and promotes effective social, environmental and economic gains at the local level and ensures savings and income for communities. The aim of this paper is the development, manufacture, and characterization of PP and HDPE recycled polyolefin blocks as masonry components in civil construction. These blocks were manufactured by the rotational molding process. Besides this, the mechanical, physical, impact and flammability properties of the blocks were studied. In conclusion, HDPE showed better behavior than PP in tests realized.

Açaí (Euterpe oleracea Mart.) is a native fruit of the Amazon, and its production chain is centered in the state of Pará. The processing of açaí fruits generates large amounts of solid waste, which can pose serious risks to the environment if not used and managed properly. The novelty of this research lies in the fact that until this moment, no research had been reported in the literature on the pyrolysis of açaí fibers and the chemical composition of the aqueous phase, making possible a broad set of applications including biogas production. The present research proposes a study of the pyrolysis of açaí seeds and fibers and the physicochemical and compositional characterization of the aqueous phase products. In this way, açaí processing residues were collected in the city of Belém, PA. The seeds and fibers were dried and impregnated with NaOH solutions, and subsequently subjected to pyrolysis on a laboratory scale. The liquid products from pyrolysis were characterized through acidity index analysis, FT-IR, and gas chromatography. The increase in the concentration of the impregnating agent led to an increase in bio-oil yield from both the seeds (ranging from 3.3% to 6.6%) and the fibers (ranging from 1.2% to 3.7%). The yield in the aqueous phase showed an inverse behavior, decreasing as the concentration of NaOH increased, both in the seeds (ranging from 41% to 37.5%) and the fibers (ranging from 33.7% to 21.2%). High acidity levels were found in the liquid products studied, which decreased as the concentration of the impregnating agent increased. The increase in the concentration of the impregnating agent (NaOH) influenced the chemical composition of the obtained liquid products, leading to a decrease in oxygenated compounds and an increase in nitrogenous compounds in both experimental matrices, which was also evidenced by the reduction in acidity.

Objective: This study aimed to monitor the use of a short-wave ultraviolet (UV-C) decontamination device for N95 masks at the João de Barros Barreto University Hospital, Belém, Pará, Brazil. The research investigated the reuse of masks, storage methods, and the perception of healthcare professionals regarding the decontamination protocol using UV-C after each work shift. Theoretical Framework: The research is based on theories related to biosafety and occupational health, focusing on the importance of decontamination processes in hospital settings to enhance the protection of healthcare workers and reduce infection risks. Method: A cross-sectional study was conducted with 295 nursing professionals, including nurses, technicians, and assistants. Data were collected through a questionnaire addressing the reuse of N95 masks, storage between uses, and opinions on the use of the UV-C device for decontamination. Results and Discussion: All participants (n=295) agreed that UV-C decontamination improves biosafety by reducing the handling of potentially contaminated masks. The acceptance of the device was unanimous, confirming its feasibility both in high-demand scenarios, such as the Covid-19 pandemic, and in routine hospital practices. Research Implications: This study demonstrates that implementing UV-C decontamination systems is a practical and effective solution for hospitals, with the potential to increase occupational safety and reduce infectious waste generation. Originality/Value: The study contributes to the literature by highlighting the feasibility and benefits of reusing N95 masks with UV-C decontamination, promoting greater safety in hospital environments.

Este estudo acompanhou a utilização de um dispositivo de descontaminação ultravioleta de ondas curtas (UV-C) para máscaras N95 no Hospital Universitário João de Barros Barreto, Belém, Pará, Brasil, por meio de estudo transversal, com 295 participantes, entre enfermeiros, técnicos e auxiliares de Enfermagem. O questionário de pesquisa abordou a reutilização das máscaras N95, as formas de armazenamento entre os usos, e a impressão dos entrevistados sobre o protocolo de descontaminação das máscaras após cada turno de trabalho, com uso do dispositivo UV-C. Os resultados demonstram a aceitação unânime do dispositivo. A totalidade (n=295) dos entrevistados reconhecem que a descontaminação da máscara N95, antes do armazenamento e reutilização, eleva a biossegurança, pois reduz o manuseio de máscaras contaminadas com agentes infecciosos. Este estudo confirmou que a implementação de um sistema de descontaminação UV-C para máscaras N95 é viável em hospitais, não só em situações de alta demanda e escassez de equipamentos de proteção, como ocorreu na pandemia de Covid-19, mas também na rotina hospitalar, para a segurança ocupacional e para a redução do lixo infectante.