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Nitrogen oxides (NOx) are one of the growing air pollutants in industrial countries, and their emissions are regulated by stringent legislation. Therefore, the design of the catalyst comprised of metal oxides and ZIFs a potential solution for improving selective catalytic reduction (SCR) of NOx. Here, an efficient strategy was described to fabricate Co-ZIF/WO3 heterostructures for SCR of NOx. First, WO3 nanostructures were fabricated by the solvothermal method, and subsequently epitaxial growth of ZIF-67 on the metal oxide surface to create a new type of semiconductor Co-ZIF/WO3 heterostructures. The obtained heterostructures were systemically characterized by wide-angle XRD, FESEM, UV DRS, FT-IR, AFM, and TEM spectroscopies. The Co-ZIF/WO3 heterostructures shift the temperature corresponding to the maximum conversion around 50 °C towards lower temperatures. The maximum conversion is substantially enhanced from 55% at 400 °C to 78% at 350 °C. The enhanced activity is attributed to better interaction and synergic effect of WO3 incorporated into ZIF-67 and also the electron transfer facility between the WO3 and Co species in Co-ZIF/WO3 heterostructures. Moreover, Co-ZIF/WO3 results in a distinct effect on the production of carbon monoxide (CO) in the product gas stream. The current study highlights some of the challenges in the development of semiconductor-based heterostructures for a decrease in air pollution.
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This study was aimed to investigate the synergistic effect of sulfite reducing agent on the UV/hematite (α-Fe2O3) photocatalytic process performance in the removal of ciprofloxacin from the aqueous solutions. For this purpose, influence of the operation parameters including initial antibiotic concentration, pH, sulfite to hematite molar ratio and the reaction time on the UV/hematite/sulfite (UHS) performance was evaluated. UV alone, UV/hematite (α-Fe2O3) (UH) and UV/sulfite (US) processes indicated to have little influence on the ciprofloxacin degradation. The simultaneous presence of hematite and sulfite in the reaction environment was significantly improved the degradation efficiency, as UHS process indicated an increase of 89%, 64% and 59% in the removal performance than that of UV alone, UH and US processes, respectively. Under the selected condition (pH of 7.0 and sulfite/hematite molar ratio of 1:3), 94% of ciprofloxacin (CFX) was degraded after 5 min of reaction. In addition, robs (mg L-1 min) value for UHS process was 25.26, 6 and 4.8 times that of UV alone, UH and US processes, respectively. The EEO and TCS values for UV alone, US, UH and UHS processes were (44.21 kWh/m-3 and 2.08 $ m-3), (10.5 kWh/m-3 and 1.1 $ m-3), (4.8 kWh/m-3 and 1.04 $ m-3) and (1.75 kWh/m-3 and 0.85 $ m-3), respectively. In addition, the study of the reaction mechanism showed hydroxyl and sulfate radicals play a vital role in the degradation of CFX by UHS process.
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Rayos Ultravioleta , Contaminantes Químicos del Agua , Compuestos Férricos , Ciprofloxacina , Contaminantes Químicos del Agua/análisis , SulfitosRESUMEN
A novel strategy was described to fabricate hematite-MOF materials with morphologies (core-shell) and (composite) as an efficient peroxymonosulfate (PMS) activator for degrading ciprofloxacin (CIP) antibiotics. First, α-Fe2O3 nanoparticles (NPs) with a size distribution range of 80 nm were prepared by surfactant-assisted reflux method. Then, cobalt-based metal-organic framework (ZIF-67) was grown onto the α-Fe2O3 NPs with ultrasonic and solvothermal method, which can control the nanostructures morphology. The physicochemical properties of these nanostructures were probed by ATR-IR, WA-XRD, FESEM, VSM, TEM, and EDS spectroscopy. The results showed that all the added CIP (20 ppm) antibiotics were completely degraded in 30 min in the α-Fe2O3/ZIF-67 (0.10 g/L) and PMS (0.20 g/L) system with rate constant of 0.130 min-1. To validate the merits of the α-Fe2O3/ZIF-67, α-Fe2O3@ZIF-67 core-shell nanostructures were also applied under similar conditions. The findings demonstrated that Co/Fe species within α-Fe2O3/ZIF-67 composite catalyzed PMS synergistically to the formation of the OH and SO4- and 1O2 for CIP degradation. Furthermore, α-Fe2O3/ZIF-67 showed good recyclability enabling facile separation of the catalyst from reaction mixtures using an external magnet. The current protocol can be a useful criterion in designing various Magnetic-MOF composites with controlled morphologies for environmental remediation.
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Ciprofloxacina , Nanocompuestos , Catálisis , Compuestos FérricosRESUMEN
This study investigates the concentrations of PM10-bound PAHs and their seasonal variations in three cities of Ahvaz, Abadan, and Asaluyeh in Iran. The mean concentrations of PM10 in two warm and cold seasons in Ahvaz were higher and in Abadan and Assaluyeh were lower than the national standard of Iran and the guidelines of the World Health Organization. The Σ16 PAHs concentration in ambient air PM10 during the cold season in Ahvaz, Abadan and Asaluyeh was 244.6, 633, and 909 ng m- 3, respectively, and during the warm season in Ahvaz, Abadan, and Asaluyeh was 242.1, 1570 and 251 ng m- 3, respectively. The high molecular weight PAHs were the most predominant components. The most abundant PAHs species were Pyr, Chr, B [ghi] P, and Flt. The results showed that the total PAHs concentration in the cold and warm seasons was dependent on industrial activities, particularly the neighboring petrochemical units of the city, vehicular exhausts, traffic and use of oil, gas, and coal in energy production. The total cancer risk values as a result of exposure to PAHs in ambient air PM10 in all three cities for children and adults and in both cold and warm seasons were between 1 × 10- 6 and 1 × 10- 4, and this indicates a potential carcinogenic risk. Therefore, considering the various sources of air pollutants and its role on people's health, decision makers should adopt appropriate policies on air quality to reduce the ambient air PAHs and to mitigate human exposure.
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The aim of this study was to determine the correlation between PM2.5 and NO2 pollutants and oxidative stress marker (8-isoprostane) and lung function tests (FVC and FEV1) in healthy children who were living and studying in three different areas of Ahvaz city including A1: Naderi site with high traffic, A2: Alavi Alley site with average traffic, and A3: Ein 2 site with low traffic (a rural area on the suburb of Ahvaz). 30 students in the 12-13 year-old range were selected from each studied zone (1, 2 and 3 sites) during three months of year. Of each student, one sample was taken every two weeks to measure 8-isoprostane of exhaled breath condensate (EBC). Air pollution data were collected from three air quality monitoring stations. Also, the relationship between air pollution and 8-isoprostane as well as lung function tests were determined using generalized estimating equations (GEE). The mean concentration of PM2.5 and NO2 in A1, A2 and A3 areas were 116, 92 and 45 (µg/m3) also 77, 53 and 14 (ppb) respectively. Among all studied students, there was a significant correlation between the increase of mean concentration of PM2.5 and NO2 in 1-4 before sampling day, increased 8-isoprostane concentration and decreased FEV1, while there was no significant correlation between them and decreased FVC. In A1 site, an increase in IQR (13 µg/m3) PM2.5 and IQR (6.5 ppb) NO2 on 1-4 days before sampling was associated with 0.38 unit (95% CI: 0.11, 0.65) and 1.1 unit (95% CI: 0.85, 1.35) increase in 8-isoprostane concentration, also decreased 121 ml and 190 ml FEV1, respectively. Results showed that the short-term exposure to traffic-related air pollution can decrease the values of lung function indices and increase the oxidative stress. It may adversely affect children's lungs.
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Dust storm in Khuzestan region is strongly influenced by transportation and influx of large amount of particulate matter from internal sources (Hawizeh Marshes and East Ahwaz) and external sources (the Arabian Desert in Saudi Arabia, Jordan, Syria and the Sahara Desert). Particulate matter is one of the main components of indoor and outdoor air quality that can be very dangerous for human. The principal objective of this study was the pinpoint of the source of airborne particulate matter by the NOAA HYSPLIT model in Ahvaz City, southwest of Iran. The investigation of dust storm and their origin was performed by the GFSG Meteorological Data (backward trajectories ending analysis of the NOAA HYSPLIT model) and collecting particulate samples with high-volume air samplers during the fall and winter seasons. The results showed the average ambient particulate matter concentration in the cold and warm seasons was 158 and 161 µg/m3, respectively. Moreover, the average particulate matter concentration in the cold season was significantly higher than the standard level as presented in the National Ambient Air Quality Standard. Consequently, it seems essential to develop green space, decrease particulate emission from source and make determined efforts to control dust at governmental and international scales.
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Contaminantes Atmosféricos/análisis , Polvo/análisis , Material Particulado/análisis , Contaminación del Aire/análisis , Ciudades , Monitoreo del Ambiente/métodos , Irán , Imágenes Satelitales , Estaciones del AñoRESUMEN
Cardiovascular disease is one of the main causes of death in Iran. The aim of this study was to determine the relation between air pollution and cardiovascular hospital admissions in Ahwaz, Iran. Daily information about cardiovascular hospital admissions (based on the ICD-10) and data on air pollutants during 2008-2018 were inquired. A quasi-Poisson regression combined with linear distributed lag models; adjusted for trend, seasonality, temperature, relative humidity, weekdays and holidays was used to assess the relation between hospital admission for cardiovascular diseases and the average daily air pollution. The results of this study showed a significant increase in cardiovascular hospital admissions in the total population and women's population in relation to O3. There was a significant increase in hospital admissions for cardiovascular diseases in the whole population as well as gender and age groups associated with NO2 and NO. A significant increase was found in hospital admissions for cardiovascular diseases in relation to CO in the 65-74-year-old population. Finally, the results of this study showed that there was a significant increase in hospital admissions for cardiovascular disease associated with SO2. The main results of the present study confirm the deleterious short term impact of air pollution on cardiovascular morbidity in Ahvaz city. This evidence empasizes the need to implement policies for reducing air pollution.
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Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Enfermedades Cardiovasculares/epidemiología , Material Particulado/análisis , Admisión del Paciente/estadística & datos numéricos , Anciano , Enfermedades Cardiovasculares/terapia , Ciudades , Humanos , Irán , Tamaño de la Partícula , Distribución de PoissonRESUMEN
According to studies, high concentration of fluoride in drinking water has adverse health effects such as dental and skeletal fluorosis. This data analyzes the concentrations and health risks of fluoride in 30 drinking water samples collected from 11 villages of the Khash city, Sistan and Baluchistan province in Iran. Fluoride concentration was measured using SPADNS method according to the standard method for examination of water and wastewater. Data indicated that average fluoride concentration in drinking water was 0.731â¯mgâ¯L-1. The mean estimated daily intake (EDI) values for fluoride in different groups of infants, children, teenagers and adults were 0.0058, 0.0414, 0.0292 and 0.0234â¯mg/kg, respectively. Also, risk assessment data indicated that hazard quotient (HQ) value of groundwater samples was less than one in 90% of samples in age groups of infants, children, teenagers and adults.
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This data article aimed to investigate the quality of drinking water of Qorveh and Dehgolan Counties in Kurdistan province based on the water quality index (WQI) and agricultural quality index based on RSC, PI, KR, MH, Na, SAR and SSP indices. Also, Piper diagram was used to determine hydro chemical features of the groundwater area. The calculation of WQI for groundwater samples indicated that 36% of the samples could be considered as excellent water and 64% of the samples were classified as good water category. The results of the calculated indices for agricultural water quality indicate that water quality in all collected samples are in a good and excellent category. The Piper classification showed that dominant type of groundwater hydro chemical faces of region was calcium bicarbonate (Ca-HCO3-).
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The human body is primarily water and healthy drinking water is vital to human life. Today, the bottled-water industry has been widely developed in most countries and more than 150 several brands of bottled water are produced in Iran. Considering the increasing consumption of bottled water and its potential for contamination with harmful chemical and microbial agents such as nitrate, the aim of this study was to assess the nitrate concentration and also the microbial quality of bottled water in a number of brands produced in the Torbat-e Heydarieh city in 2017. In present descriptive-analytical research, random sampling (80 samples) was done by collecting 1.5â¯l bottled water with different production dates from 20 factories. These samples were collected in four different seasons. Measurement of nitrate concentration and microbial quality including total and fecal coliforms, were performed according to the Standard Methods for the Examination of Water and Wastewater. The results indicated that, in general, the mean concentration of nitrate in all samples was range 0.6-16â¯mg/L and all samples are within the national standard of Iran (less than 50â¯mg/L) and international standards. Also, total coliforms and fecal coliforms in any of the studied samples were zero.
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The main of this data was determine the concentrations and health risks of fluoride in 66 drinking water samples collected from villages of the Iranshahr city, Sistan and Baluchestan Province in Iran. Fluoride concentration was measured by the standard SPADNS method. Data indicated that fluoride concentration in drinking water ranged from 0.25 to 1.72â¯mgâ¯L-1 and average of fluoride concentration was 0.27â¯mgâ¯L-1. The mean estimated daily intake (EDI) values for fluoride in different groups of infants, children, teenagers and adults were 0.0021, 0.0151, 0.0107 and 0.0086â¯mg/kg, respectively. Also, risk assessment data indicated that hazard quotient (HQ) value of groundwater samples is more than 1 in 6% of groundwater samples in age groups of children and teenagers.
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In this article the data of the groundwater quality of Aras catchment area were investigated for estimating the sodium absorption ratio (SAR) in the years 2010-2014. The artificial neural network (ANN) is defined as a system of processor elements, called neurons, which create a network by a set of weights. In the present data article, a 3-layer MLP neural network including a hidden layer, an input layer and an output layer had been designed. The number of neurons in the input and output layers of network was considered to be 4 and 1, respectively, due to having four input variables (including: pH, sulfate, chloride and electrical conductivity (EC)) and only one output variable (sodium absorption ratio). The impact of pH, sulfate, chloride and EC were estimated to be 11.34%, 72.22%, 94% and 91%, respectively. ANN and multiple linear regression methods were used to estimate the rate of sodium absorption ratio of groundwater resources of the Aras catchment area. The data of both methods were compared with the model׳s performance evaluation criteria, namely root mean square error (RMSE), mean absolute error (%) and correlation coefficient. The data showed that ANN is a helpful and exact tool for predicting the amount SAR in groundwater resources of Aras catchment area and these results are not comparable with the results of multiple linear regressions.
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The aim of this study was to evaluate the groundwater quality Indices of Groundwater resource for Agricultural Use in jolfa city (Iran) during one decade (2003-2013). Data showed in the first and end year of the study period, the Mean±SD of Sodium Adsorption Ratio (SAR) and Sodium Percentage (Na%) indices 5455.77±3878.02, 3638.69±3565.19 and 51.49±15.65, 41.58±17.69, respectively. The data indicate that the, in terms of sodium percentage and sodium adsorption ratio, the water quality in this area is not suitable for irrigation.