H Irvani, H Shojaee - Farah Abady, M Shahryari, M Nakhaei Pour,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Styrene monomer is a volatile organic compound that is used in the various industries. Due to the hazardous effects of this chemical substance on the environment and humans, control and elimination of this vapour is necessary. Therefore, the aim of this study was to remove the styrene vapors from air flow using photocatalytic activity of zinc oxide immobilized on ZSM-5 zeolite.
Materials and Methods: In this experimental study, the fabricated catalysts were characterized using analysis of BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dynamic Concentrator System were used to generate styrene vapors at a certain concentration and flow, and then removal efficiency of the styrene vapors was investigated using UV/ZnO and UV/ZSM-5/ZnO.
Results: The results of XRD analysis and SEM images showed that produced zinc oxide had nano dimensions. In addition, these nanoparticles was successfully stabilized on ZSM-5 zeolite. The results of the photocatalytic removal showed that ZnO and ZSM-5/ZnO catalysts at the concentrations of 50 ppm eliminated the styrene vapor 14% and 37%, respectively.
Conclusion: Findings of this study showed that stabilization of zinc oxide nanoparticles on ZSM-5 zeolite had an ssynergistic effect on the photocatalytic degradation of styrene. According to this finding, the use of adsorption-photocatalyst hybrid systems can be an appropriate technique to remove styrene vapors and other similar pollutants.
Bahram Kamarehie, Majid Irvani Mofard, Nahid Khoshnamvand, Mohammadreza Samaei, Faramarz Azimi, Ali Tolabi,
Volume 18, Issue 2 (9-2025)
Abstract
Background and Objective: Although hygiene standards are often not fully observed in the preparation of many foods, the demand for ready-made meals has increased due to urbanization and time constraints. This study aimed to investigate and compare the microbial load on surfaces, equipment, and restaurant workers' hands before and after disinfection with savory extract, and to compare its effectiveness with ethanol in restaurants across Shiraz.
Materials and Methods: Ten restaurants in Shiraz were selected through simple random sampling for this study. A total of 180 culture media were prepared to identify Staphylococcus aureus and Escherichia coli contamination. Microbial load was quantified using luminometry. Data were analyzed using descriptive statistics, including measures of central tendency and dispersion.
Results: Following intervention with savory extract, microbial analysis revealed maximum Staphylococcus aureus contamination (33 CFU) on workers' hands in Restaurant C, while Restaurant J showed the lowest contamination level (16 CFU). Notably, alcohol-based intervention completely eliminated both S. aureus and E. coli contamination (0 CFU) across all sampled restaurants.
Conclusion: The findings demonstrate significant deficiencies in both food contact surface sanitation and worker hand hygiene across the studied restaurants, posing substantial public health risks. These results underscore the critical need for: (1) enhanced food safety training programs for food handlers, (2) strict personal hygiene protocols, and (3) rigorous regulatory inspections to mitigate potential health hazards.
