The purification of used oils and their introduction into production cycles lead to reduction in environmental contamination. A simulation was conducted to study the thermal degradation of sunflower oil under varying temperatures over time. In the purification process of used cooking oil, an adsorption technique using zeolite and eggshell as an adsorbent (5, 10, 20, and 30 g/100 mL used oil) was applied. To optimize purification, different doses of thermally and chemically activated adsorbents were used, at different temperatures (30 and 80 °C). Therefore, this study was conducted in batch operations to determine the effect of suitable adsorption for a contact time of the adsorbent of 2 h. In comparison, the purification of used vegetable oils was achieved using a saline solution. The adsorption capacity was evaluated by determining the physicochemical parameters of the oils before and after purification. The characterization of natural adsorbents was carried out using scanning electron microscopy (SEM) and X-ray fluorescence spectrometry (XRF). The results showed that the adsorbent in a dose of 30 g of zeolite activated with NaOH and heat-treated eggshell, respectively, exhibited a larger surface area and greater adsorption capacity. Adsorption increased with contact time. The FT-IR spectra of the oils showed the IR bands at 1097, 1160, and 1237, corresponding to the presence of the ester C-O-, 1743 for C=O ester, 2853, 2922 for (CH₂, CH₃), and 3008 for (C=C). The acidity and peroxide values decreased with increasing dose and contact time with zeolite or eggshell. Together, our result strongly suggests that natural adsorbents contribute to the purification of used oils.

The dissolution of the main metals (Cu, Zn, Sn, Pb and Fe) found in waste printed circuit boards (WPCBs) was investigated by electrochemical corrosion measurements (potentiodynamic polarization and electrochemical impedance spectroscopy (EIS)) in different bromide-based systems that could be used as lixiviants in hydrometallurgical route of metals recovery. The analysis of the corrosion products was carried out by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements. All measurements showed that the addition of bromine in the electrolyte favors to great extents the dissolution process of all studied metals as compared to bromine-free electrolytes. In the investigated experimental conditions, the highest dissolution rates of the metals were obtained in acidic KBr solution containing 0.01 mol/L bromine and they decreased in the following order: Zn >> Sn > Pb > Fe > Cu. The XRD and XPS chemical assessment allowed the identification of the dissolution products formed on the metallic surfaces after exposure to the electrolytes. They consisted mainly of oxides in the case of Cu, Zn, Sn and Fe, while the presence of PbBr₂ was also noticed on the lead surface. Based on the results of EIS and surface investigations, several models explaining the corrosion behavior of the metals were proposed and discussed. The obtained results demonstrate that all studied metals could be successfully leached using brominated solutions, providing a viable alternative for the selective and efficient recovery of the base metals from WPCBs through a multi-step hydrometallurgical processing route.

Occupational health and safety (OHS) is essential for protecting the life, health, and physical integrity of workers. In a complex and dynamic professional context, the prevention of occupational risks has become a priority for employers and decision-makers, going beyond legal compliance to create a safe and efficient work environment. This article explores the history and the main theoretical aspects of OHS and explores the implementation of the ISO 45001 standard and introduces managing workplace health and safety (WHS) risks based on the 5M Method and a weighted composite algorithm for OHS risk assessment integrating factors such as severity, probability, frequency of exposure, number of exposed employees, organizational response capacity, and incident history. Applied in a mixed industrial case study, this approach demonstrated superior risk prioritization compared to the classic severity–probability model. The findings have practical applications: organizations can use the Weighted Composite Score to prioritize interventions, allocate resources efficiently, and prevent high-risk incidents. The approach is adaptable across industries, supporting data-driven safety decisions. The integration of this method supports ISO 45001’s principles of a systematic, proactive, and continuous improvement approach to OHS management.

This paper presents a new risk assessment methodology called the Integrated Risk Framework (IRF) through the application of Ishikawa diagrams combined with the enhanced Hazard Analysis and Critical Control Point (HACCP) system. This risk investigation technique aims to ensure a significantly higher level of quality, safety, and sustainability in food products by using improved classical methods with strong intercorrelation capabilities. The methodology proposes expanding the typology of basic physical, chemical, and biological risks outlined by the ISO 22000 Food Safety Management System standard, adding other auxiliary risks such as allergens, fraud/sabotage, Kosher/Halal compliance, Rapid Alert System for Food and Feed notification, or additional specific risks such as irradiation, radioactivity, genetically modified organisms, polycyclic aromatic hydrocarbons, African swine fever, peste of small ruminants, etc. depending on the specific technological process or ingredients. Simultaneously, it identifies causes for each operation in the technological flow based on the 5M diagram: Man, Method, Material, Machine, and Environment. For each identified risk and cause, its impact was determined according to its severity and likelihood of occurrence. The final effect is defined as the risk class, calculated as the arithmetic mean of the impact derived at each process stage based on the identified risks and causes. Within the study, the methodology was applied to the spring water bottling process. This provided a new perspective on analyzing the risk factors during the bottling operations by concurrently using Ishikawa diagrams and HACCP principles throughout the product’s technological flow. The results of the study can form new methodologies aimed at enhancing sustainable food safety management strategy. In risk assessment using these two tools, the possibility of cumulative or synergistic effects is considered, resulting in better control of all factors that may affect the manufacturing process. This new perspective on studying the dynamics of risk factor analysis through the simultaneous use of the fishbone diagram and the classical HACCP system can be extrapolated and applied to any manufacturing process in the food industry and beyond.

Pollution in mining areas represents a major environmental issue, significantly impacting ecosystems and human health. This study highlights propolis as an efficient natural bioindicator for detecting and assessing the degree of contamination in these areas. The objective of this study is to determine the levels of metals (Pb, Cd, As, Cr, Fe, Mn, Cu, and Zn) in propolis from mining exploitation areas in Romania, specifically in the counties of Alba, Hunedoara, Maramureș, and Caraș-Severin. Although mining operations are closed, the anthropogenic impact varies due to differences in the surface areas of the zones affected, the areas occupied by waste heaps, local hydrological conditions, and partial ecological rehabilitation efforts. To highlight the impact of contamination, a reference area considered unaffected by anthropogenic activities was used as a benchmark for each county. The values obtained in the investigated area were compared with those from this control zone to determine the differences and the specific impact of pollution. Maximum values were recorded in Roșia Montană for Pb (9.27 mg·kg⁻¹), Cd (0.17 mg·kg⁻¹), and As (0.87 mg·kg⁻¹); in Băile Borșa for Fe (150.23 mg·kg⁻¹) and Zn (2.9 mg·kg⁻¹); in Certeju de Sus for Cu (6 mg·kg⁻¹) and Cr (7.01 mg·kg⁻¹); and in Moldova Nouă for Mn (25.43 mg·kg⁻¹). The maximum content values of phenols (189.49 mg·kg⁻¹ in Alba County) and flavonoids (88.06 mg·kg⁻¹ in Caraș-Severin) were recorded, as well as the minimum IC₅₀ antioxidant activity (0.33 µg·mL⁻¹). Propolis from these areas showed antimicrobial activity against five bacterial strains (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Streptococcus mutans) and five fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Cryptococcus neoformans, and Penicillium chrysogenum), although such antimicrobial and antifungal activities were more intense in unpolluted areas. The present study reveals that propolis is a natural indicator of heavy metal pollution in mining areas. These data support the usefulness of propolis due to its high capacity to accumulate and reflect environmental contaminants.

The objective of this paper was to study the phyto-inhibitory and antimicrobial activity of brown propolis collected from the counties of four regions in Romania. The main physico-chemical and functional properties of 16 samples of propolis from different landforms of geographical regions were determined. Their antimicrobial activities were established against 5 bacterial strains (Pseudomonas fluorescens, Bacillus subtilis, Bacillus cereus, Escherichia coli, and Proteus mirabilis) and 5 fungal strains (Alternaria alternata, Cladosporium cladosporioides, Fusarium oxysporum, Mucor racemosus, and Aspergillus niger). Simultaneously, the phyto-inhibitory effect of propolis samples on different cereals was highlighted: hexaploid bread wheat (Triticum aestivum), maize (Zea mays L.), oats (Avena sativa L.), and barley (Hordeum vulgare L.). Correlations between the antioxidant activity and total flavonoid and phenol content of the propolis samples were identified, respectively, and the statistical analysis highlighted that the diameter of the inhibition zone was influenced by the strain type (bacterial and fungal) and the geographical regions of propolis. Principal component analysis (PCA) indicated that out of seven principal components, only two exhibited > 0.5. Pearson’s correlation coefficient showed a low and moderate positive linear relationship between the diameter of the inhibition zone and the flavonoid and phenol concentration of the propolis samples.