Iranian Journal of

Background and Objective:  Arsenic has long been considered as a heavy metal and toxic pollutant due to its potential to harm the human health and the environment. Adsorption is one of the mechanisms for arsenic removal from wastewater. Therefore, the purpose of this research was to investigate the feasibility of synthesized chitosan-zirconium magnetic nano fiber on arsenic adsorption from wastewater and to evaluate its kinetic and isotherm models.
Materials and Methods: Synthesis of nanofibers was performed by electrospinning method and the optimal formulation was determined following the experimental design. Then, kinetics and isotherms of arsenic adsorption on the as synthesized nanofibers were investigated. The prepared nanofiber was characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM), Infrared Fourier Transform (FT-IR) and Vibrational Sampler Magnetic Meter (VSM).
Results: The optimal formulation was obtained: 2.84% chitosan, 0.97% nano-zirconium and 0.94% nano-iron. The adsorption of arsenic on synthetic fibers was found to follow quasi-first-order kinetics and the Freundlich isotherm. Furthermore, the effect of initial concentrations of arsenic, contact time, temperature and pH on arsenic adsorption were surveyed. The optimal condition for nitrate arsenic adsorption was obtained at initial concentration of 70 mg/L, 45 min contact time and at pH 3.
Conclusion: According to the results, the synthesized nanofiber displayed a regular network structure with the distribution of the Zr-nanoparticles in its shape. Also, according to the form of magnetometric analysis, it was found that chitosan-nanosirconium magnetic nanofibers are well magnetized and are free magnetic.  Finally, it can be concluded that the synthesized nanosorbent has a high potential for arsenic removal from industrial effluents.

Background and Objective: Conversion of houses into residential towers in worn-out urban textures increases population. Schools of the vicinity would face with multiplicity and limited space for students, leading to noise pollution. The purpose of this study was to evaluate the noise levels during morning and afternoon shifts among two primary schools in Zanjan.
Materials and Methods: Measurements had been done using sound level meter, KIMO DB100. The equivalent noise level (L_eq) measured during school year (2018-2019) in 10 stations. The measurements were done in three seasons (autumn, winter and spring) and in each season for two weeks. The data of the two schools were used for drawing charts and zoning by ArcGIS using IDW method. In addition, questionnaires were distributed among the teachers and school’ neighbors. The data were analyzed by SPSS software.
Results: The results showed that all the stations were tackled with noise pollution. The highest levels were related to school’s shift change and break times. The morning shift schools experienced higher levels of noise in comparison to the afternoon ones (1.87 and 2.1 dB, respectively for boys and girls). L_eq values for boys’ school was 2 dB higher than that of the girls’. The noise level in the schools were 72 dB, which is 17 dB higher than the standard level 55 dB.
Conclusion: The residents living close to the schools were exposed to noise pollution for almost 10 hours a day. This could be regarded as harmful. The zoning maps showed that southwest side of the yard, adjacent to the neighboring residential buildings, had the highest levels of noise. This study demonstrated the site selection for the schools were not properly done.  Having a control strategy is needed.

Background and Objective: Indoor air pollution in hospitals could be a serious health threat to the patients, medical staff, and visitors. In previous studies, the importance of paying attention to air quality during the Coronavirus pandemic has been proven. In this study, the effect of visiters' presence under normal conditions and the imposition of hospital restrictions at the time of pandemic on air quality and environmental parameters in a hospital has been evaluated.
Materials and Methods: Air sampling was carried out in Valiasr Hospital of Zanjan in two periods, September 2019 (morning and visiting hours) and during the pandemic in October 2020. All wards inside and the outside of the hospital were examined for air pollutants (PM_2.5, PM₁₀, NO₂, SO₂, CO₂) and environmental parameters (temperature, humidity, and sound levels).
Results: The results of this study showed that except for the sound levels, other pollutants are at an acceptable level. Particulate matter of different sizes in the air of the hospital has a correlation, often with an external source, and has been imported through construction activitie;. However, nitrogen dioxide concentration is dependent on urban traffic. Visiting hours are associated with an increase in the concentration of particulate matter and the sound levels. The pandemic had a positive effect in some wards, on some parameters and often improved the air quality due to the imposing strict health protocols.
Conclusion: This study showed that natural ventilation has a direct effect on the air quality inside of the hospital. It is also suggested that in wards where patients are sensitive or in the need of intensive care, restrictions on commuting and visitation be applied.

Background and Objective: Bioaerosols as small particles enter the body by inhalation and lead to respiratory diseases based on type, concentration, and exposure time. In sensitive workplaces such as medical centers, it is necessary to pay attention to the type and population of these pollutants and the possibility of nosocomial infections. In the present study, the population and type of bioaerosols (bacteria and fungi) in the air of different hospital wards under normal conditions, visiting hours, and Covid-19 pandemic was evaluated.
Materials and Methods: Air sampling was carried out in different wards and ambient air of Valiasr Hospital of Zanjan during September 2019 (morning and visiting hours) and October 2020 (Corona pandemic) using an air sampling pump (Flite 3- SKC Ltd) with a flow of 14.1 L/min and then cultured in Sabaroud dextrose agar and nutrient agar.
Results: The results showed that air pollution in wards such as infectious diseases and clinics in both periods was more than other wards. The microbial density during visiting hours (before the coronavirus outbreak) was almost 30% higher than normal conditions. In October 2020, due to the coronavirus outbreak and reduced traffic, microbial air pollution in the hospital decreased. In both periods of study, the frequency of gram-positive bacteria, especially Staphylococcus species (49%) was higher than other bacteria and among fungal species the frequency of Aspergillus (47%) was higher than others.
Conclusion: This study showed that traffic restrictions caused by the coronavirus pandemic reduce microbial density in hospital space and this achievement can be used in the future with the aim of improving air quality and controlling nosocomial infections.
 

Background and Objective: Based on its unique characteristics, oil industry wastewater must be treated before discharging into the environment. The study aimed to optimize the catalytic sonopraxone process in the treatment of petroleum wastewater using a statistical method.
Materials and Methods: The synthesis of Iron Oxide-Zinc Oxide was carried out by air oxidation and layer-by-layer self-assembly method. XRD, SEM, EDAX, FT-IR, BET, DRS, VSM and TGA techniques were used to investigate the structure. In this study, applied CCD method optimization of pH parameters, reaction time, ozone gas concentration, hydrogen peroxide concentration and catalyst amount in the process. In optimal conditions, BOD₅ and TPH removal values, reaction kinetics and synergistic effect of mechanisms were studied. COD, TPH and BOD₅ were measured by spectrophotometer (DR6000), GC-FID and incubator, respectively.
Results: The results indicated that the Fe₃O₄@ZnO structure is well formed. A quadratic model was proposed to model the process based on the correlation coefficient. Based on ANOVA analysis and p and f indices, the proposed model was reported to be significant. Optimum conditions include pH 6.4, ozone concentration 1.3 mg/L.min, hydrogen peroxide concentration 2.5 mL/L, reaction time 51 min and catalyst amount equal to 0.64 g/L. In these conditions, the amount of COD reduction was 82.3 and 70% theoretically and experimentally, respectively. Also, in optimal conditions, BOD₅ and TPH removal rates were 90.5% and 85.8%, respectively. The kinetics of the process follows the kinetics of the first order (R²=0.98) and the presence of different mechanisms together causes a synergistic effect and increases the efficiency of the process.
Conclusion: This process can improve the quality of oil effluent based on COD, BOD₅, and TPH removal.
 

Background and Objective: The use of pesticides poses serious risks to the health of living organisms. Knowing the type and amount of pesticide use can provide a good information base for managing potential risks from pesticide consumption. This study was carried out with the main objective of determining the types and amounts of pesticides used on agricultural land in East Azarbaijan Province in 2021.
Materials and Methods: Information about the pesticides have been gathered and analyzed by referring to the Agricultural Jihad Organization and other relevant authorities. Calculations related to the amount of pesticides used per unit area were made using the total area of agricultural lands in the province.
Results: Considering the frequency, 403 kinds of pesticides are used in the following order: Herbicides > Insecticides > Fungicides > Acaricides > Others > Disinfectants. Consdidering total consumption of 2873730 kg pesticides, the order based on the amount is: Insecticides > Herbicide > Fungicides > Miscellaneous > Acaricides and Disinfectants based on the amount. The total ratio of pesticides used to pesticides distributed through the official (government) channel is 2.51. The minimum, maximum, and mean consumption values in counties are 0.4, 21.4, and 4.21 ± 5.33 kg/ha, respectively, and for province is 2.38 kg/ha. There is a correlation between the amount of pesticide applied and the number of farmers and traders.
Conclusion: The consumption of pesticides in the province is higher than the world average. Appropriate management of pesticides is required from the viewpoints of environment and health protection.