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Metal organic framework (Zn-MOF)/polyvinyl alcohol (PVA) nanofibrous composite new material has been fabricated using electrospinning and is characterized by a variety of physicochemical analyses, including Fourier transmitting infrared spectroscopy, X-ray powder diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy, nitrogen adsorption surface, and thermo gravimetric-derivative of thermogravimetry. In this study, the effects of a systematic study including a fractional factorial design were studied for arsenic removal. The results showed that although conventional methods have a high level of arsenic removal, the fractional factor method results in a relatively high level of absorption of arsenic. This high level of arsenic removal allows the potential use of nano adsorbents in various environmental fields. The systematic study developed in this study can be used as a novel protocol to eradicate pollution from different areas, including water, air, and soil. KEYWORDS arsenic adsorption, fractional factorial design, systematic study, Zn-MOF/PVA nanofibrous composite, 1 | INTRODUCTION Inorganic materials with combination of functionalized polymers are very interesting way to achieve advanced properties in field of chemistry and material science. [1-7] Metal organic frameworks (MOFs) [...]

Drugs, especially antibiotics, as a group of emerging contaminants, pose a serious threat to the environment and aquatic ecosystems due to their adverse effects, cumulative properties, and developing drug resistancy. Therefore, this study aimed to evaluate the removal efficiency of tetracycline (TC) antibiotic from aqueous solutions using photocatalytic process in the presence of magnetic iron sulfide (Fe-S/CuS) nanoparticles on a laboratory scale. The magnetic nanocomposite was first characterized by transmission electron microscopy, X-ray diffractometer, vibration sampling magnetometer, Field-emission scanning electron microscopy, Fourier-transform infrared spectrometer, diffuse reflection spectroscopy, and energy-dispersive X-ray spectroscopy techniques. Factors, such as pH, reaction contact time, nanocomposite dose, and contaminant concentration on the removal efficiency were studied. All the experiments were performed at room temperature under UV-A light. The results of this study indicated that the highest removal efficiency of TC was obtained at optimum pH of 7. The results also showed that in the initial concentration of TC antibiotic (20 mg/L), the removal efficiency increased by increasing contact time and also by increasing the dose of the desired nanocomposite, the removal efficiency first increased and then decreased. Moreover, the synthesized nanocomposite had the ability to be reused with an 18% reduction in the removal efficiency in five consecutive cycles. Finally, the results of this study showed the acceptable efficiency of Fe-S/CuS nanocomposite in photocatalytic removal of TC antibiotic. [ABSTRACT FROM AUTHOR]

Background and Aims: Bioaerosols are airborne particles that contain bacteria, viruse, and fungi. Human show different reactions to bioaerosols. This study aimed to determine the density of bacterial particles cultivable in the inside and outside air of kindergardens in Birjand, Iran. Materials and Methods: This study was performed based on a descriptive-analytical and cross-sectional research approach. Birjand was divided into five regions based on their geographical location, and six kindergardens were randomly selected. The sampling was performed in the morning shift from all six selected kindergartens. Additionally, triptic soy agar was used as the culture medium, and the sampling was performed at a flow rate of 28.3 L/Min for 35 min at a distance of 0.8 to 1 M above the ground in the center of each class. The data were analyzed in SPSS software (version 16) through the Mann-Whitney and Kruskal-Wallis statistical tests. A p-value less than 0.05 was considered statistically significant. Results: According to the results, the highest mean bacterial and microbial load and suspended particles were obtained at 3.83±8.04 CFU/m3 and 196.13±382.54 CFU/m3 in February and March, respectively. There was no significant relationship among bacterial density, suspended particles, and temperature (P>0.05). However, a significant relationship was observed between the bacterial density and total suspended particles (P<0.05). There was also a significant relationship between the amount of suspended particles (PM1, PM2.5, PM10) and the environment inside and outside the kindergardens (P<0.05). Conclusion: It is possible to determine the concentration of bacterial contamination in terms of quantity, type of identified species, and the amount of airborne particles to prevent the adverse health effects. [ABSTRACT FROM AUTHOR]