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Exposure to metal dust is a significant occupational hazard for foundry workers. This study aimed to investigate exposure to potentially toxic metals and oxidative stress indices and assess the health risk of occupational exposure to metal dust among foundry workers. Environmental and biological exposures to a cocktail of metals were examined by measuring the concentration of Aluminum (Al), Zinc (Zn), Copper (Cu), Cadmium (Cd), Nickel (Ni), and Chromium (Cr) in the air of the workplace, as well as in the blood of the exposed workers. Malondialdehyde (MDA), reduced blood glutathione (GSH) and urinary 8- hydroxydeoxy guanosine (8-OH-dG) were measured as biomarkers of oxidative stress. All air measurements were below the maximum allowable limits (MAL) except for Al and Ni according to American Conference of Industrial Hygienists (ACGIH) and National Institute of Occupational Safety and Health (NIOSH). Here is significantly elevated Blood Al, Zn, Cu, and Pb levels in exposed workers. Moreover, MDA and 8-OHdG levels significantly increased (P<0.0001). In contrast, the mean level of GSH was reduced considerably in exposed workers compared to the control group (P<0.0001). The MDA acts as a marker with the highest Area Under the Curve (AUC), enabling effective differentiation between the exposed and control subjects (AUC = 0.968; Sensitivity = 90%, Specificity =100%; P <0.0001). Workers occupationally exposed to these metals for prolonged periods possessed higher metal levels in their bodies, which is associated with increased oxidative stress, which consequently causes DNA damage. [ABSTRACT FROM AUTHOR]

This study reports the antibacterial and antibiofilm activities of Magnesium ferrite nanoparticles (MgFe2O4) against gram-positive and gram-negative bacteria. The photocatalytic degradation of Carbol Fuchsin (CF) dye (a class of dyestuffs that are resistant to biodegradation) under the influence of UV-light irradiation is also studied. The crystalline magnesium ferrite (MgFe2O4) nanoparticles were synthesized using the co-precipitation method. The morphology of the resulting nanocomposite was examined using scanning electron microscopy (SEM), while transmission electron microscopy (TEM) was employed for further characterization of particle morphology and size. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were utilized to analyze the crystalline structure, chemical composition, and surface area, respectively. Optical properties were evaluated using UV–Vis spectroscopy. The UV-assisted photocatalytic performance of MgFe2O4 nanoparticles was assessed by studying the decolorization of Carbol fuchsin (CF) azo dye. The crystallite size of the MgFe2O4 nanoparticles at the (311) plane, the most prominent peak, was determined to be 28.5 nm. The photocatalytic degradation of 10 ppm CF using 15 mg of MgFe2O4 nanoparticles resulted in a significant 96% reduction after 135 min at ambient temperature (25 °C) and a pH value of 9. Additionally, MgFe2O4 nanoparticles exhibited potent antibacterial activity against E. coli and S. aureus in a dose dependent manner with maximum utilized concentration of 30 µg/ml. Specifically, MgFe2O4 nanoparticles demonstrated substantial antibacterial activity via disk diffusion and microbroth dilution tests with zones of inhibition and minimum inhibitory concentrations (MIC) for E. coli (26.0 mm, 1.25 µg/ml) and S. aureus (23.0 mm, 2.5 µg/ml), respectively. Moreover, 10.0 µg/ml of MgFe2O4 nanoparticles elicited marked percent reduction in biofilm formation by E. coli (89%) followed by S. aureus (78.5%) after treatment. In conclusion, MgFe2O4 nanoparticles demonstrated efficient dye removal capabilities along with significant antimicrobial and antibiofilm activity against gram-positive and gram-negative bacterial strains suggesting their potential as promising antimicrobial and detoxifying agents. [ABSTRACT FROM AUTHOR]

Synthesis of crystalline zinc copper ferrite nanoparticles was achieved via a simple co-precipitation method. Scanning electron microscope (SEM) is utilized to give the morphological characterization of the prepared samples. A transmission electron microscope (TEM) was employed for further identification and confirmation of the particle size and morphology. Moreover, X-ray diffraction (XRD) and Fourier transformation infrared (FTIR) spectroscopy were utilized to examine crystalline structure and chemical structure, respectively. The photocatalytic performance of Zn0.5Cu0.5Fe2O4 nanoparticles under UV light was assessed by decolorization of methyl orange (MO) azo dye. The efficiency of photocatalytic degradation of 20 ppm of MO by Zn0.5Cu0.5Fe2O4 nanoparticles 15 mg was 96% after 135 min at an ambient temperature of 25 °C and pH value of 3. Further interpretation was carried out and a proposed mechanism for the MO photodegradation over Zn0.5Cu0.5Fe2O4 nanoparticles was suggested. [ABSTRACT FROM AUTHOR]

The continued pollution, waste, and unequal distribution of the limited amount of fresh water on earth are pushing the world into water scarcity crisis. Consequently, development of revolutionary, cost-effective, and efficient techniques for water purification is essential. Herein, molten flux method was used for the preparation of micro-sized Al-doped SrTiO3 photocatalyst loaded with RhCr2O3 and CoOOH cocatalysts via simple impregnation method for the photo-assisted degradation of Congo red dye under UV and visible irradiation compared with P25 standard photocatalyst. In addition, photoelectrochemical analysis was conducted to reveal the separation and transfer efficiency of the photogenerated e−/h+ pairs playing the key role in photocatalysis. SEM and TEM analyses revealed that both P25 and the pristine SrTiO3 have spherical shapes, while Al-doped SrTiO3 and the sample loaded with cocatalysts have cubic shapes with a relatively higher particle size reaching 145 nm. In addition, the lowest bandgap is due to Al+3 ion doping and excessive surface oxygen vacancies, as confirmed by both UV–Vis diffuse-reflectance and XPS analyses. The loading of the cocatalysts resulted in a change in the bandgap from n-type (pristine SrTiO3 and Al-SrTiO3) into p-type (cocatalyst loaded sample) as exhibited by Mott–Schottky plots. Besides, the cocatalyst-loaded sample exhibited good performance stability after 5 cycles of the photocatalytic removal of Congo red dye. OH· radical was the primary species responsible for CR degradation as confirmed by experiments with radical scavengers. The observed performance of the prepared samples under both UV and visible light could foster the ongoing efforts towards more efficient photocatalysts for water purification. [ABSTRACT FROM AUTHOR]

The present investigation provides a cost-effective approach to the development of nanostructured g-C3N4 coated eggshell waste-derived Ca(OH)2 nanoparticles as a photocatalyst for the degradation of Eriochrome cyanin R (ECR), and disinfection of pathogenic bacteria. The g-C3N4/Ca(OH)2 nanocomposite was characterized via XRD, SEM, EDX, and TEM. XRD patterns and TEM images revealed the successful synthesis of the samples in nanoscale range. The efficacy of the g-C3N4/Ca(OH)2 nanocomposite was assessed with different parameters, including solution pH, initial concentration of a targeted contaminant, and loading of the g-C3N4/Ca(OH)2 nanocomposite. Notably, 0.01 g of the g-C3N4/Ca(OH)2 nanocomposite achieved an impressive 90.0% removal efficiency of ECR at the solution pH of 3.0. When isopropanol was added, the photodegradation of ECR dye by the g-C3N4/Ca(OH)2 nanocomposite was decreased (42%), suggesting that the OH⋅ radical was the primary species responsible for degradation. The tested samples are effective against various bacteria, including Eschericia coli (E. coli) and Staphylococcus aureus (S. aureus). Specifically, the g-C3N4/Ca(OH)2 nanocomposite was the most effective combination against S. aureus (13.9 mm ZOI and 12.5 µg/mL MIC), and E. coli (12.4 mm ZOI and 12.5 µg/mL MIC). In reaction mechanism determination, the amount of the synthesized nanomaterials is directly correlated with the quantity of E. coli protein removed, and they were accounted as 22.23, 55.10, and 101.44 µg/mL following incubation with g-C3N4, Ca(OH)2 NPs, and g-C3N4/Ca(OH)2 nanocomposite, respectively. [ABSTRACT FROM AUTHOR]