Journal of Environmental Health and Sustainable Development
Volume:7 Issue: 2, Jun 2022

The present study aimed to investigate the change of air pollutants in 2020 in Qom compared to the same period in 2019 in five scenarios.

The hourly air quality data was obtained from air quality monitoring stations of Qom Environmental Protection Organization (EPO). The meteorological parameters were obtained from Iranian Meteorological Organization website. The data were analyzed using Excel, SPSS, and WRPLOT view.

In the first month of the COVID-19 crisis, NO2, SO2, and CO decreased by 26.4, 39, and 0.2 µg/m3 compared to same period in 2019, respectively; however, PM2.5 and O3 increased by 7.1 and 2.3 µg/m3, respectively. In Iranian Nowruz holidays, an increase of 2.9 µg/m3 in O3 mean concentration and a decrease of 8.1, 23.8, 22.8, and 0.2 µg/m3 in mean concentration of PM10, NO2, SO2, and CO were experienced. The prevailing wind direction during the 2020 in each scenario was from the west of Qom city.

Gaseous pollutants decreased during the crisis, but particulate pollutants increased slightly compared to the same period in 2019. The lockdown may have had the most impact in decreasing pollutants. A slight increase in wind speed from the west could be a factor in increasing particles. This crisis provided an opportunity to assess the role of policies, such as traffic reduction plans or discarding worn-out cars or urban management to improve air quality.

Exposure to the low frequency electric and magnetic fields (ELF-EMF) is very common in workers occupied in the combined cycle power plant during work shifts  The present study aimed to measure ELF-EMF flux density among shift and non-shift workers, determine job stress among workers and office workers, and identify major factors associated with job stress in the studied groups.

In this cross-sectional study, the exposed group was divided into 75 shift workers and 75 non-shift workers. Seventy-five office workers were selected as the reference group. The participants’ exposure to ELF-EMF was measured by the EMF-828 device. In addition, Osipow Occupational Stress Questionnaire was used to assess the participants’ stress levels.

Maximum levels of ELF-EMF among shift workers, non-shift workers, and office workers were 28.67 μT, 23.43 μT, and 0.06 μT, respectively.  Although the explosion rate to ELF-EMF was higher in the shift and non-shift workers than the office one's, this rate in both of them were lower than the recommended limit as suggested by the American Conference of Governmental Industrial Hygienists (ACGIH). The highest stress score was related to shift workers exposed to ELF-EMF, in which 42.7% of them experienced moderate to high levels of job stress. Multivariate linear regression analysis showed a significant association between shift work and exposure to ELF-EMF with increased stress.

The findings suggested that exposure to ELF-EMF, even at low intensities, is associated with increased stress. Moreover, Shift work is another risk factor for stress.

Corrosion and scaling are important factors affecting drinking water quality, causing health and economic problems. This study aimed to investigate the indicators of corrosion and scaling in Rafsanjan drinking water.

The present descriptive cross-sectional study was conducted in winter 2018 and spring 2019 in Rafsanjan. The 56 samples were randomly taken from the drinking water distribution and transmission networks. Physicochemical parameters, such as pH, temperature, total dissolved solids (TDS), total hardness (TH), calcium hardness (CH), electrical conductivity (EC), and alkalinity were measured.  Finally, corrosion and scaling indices, including langelier index (LI), ryznar index (RI), aggressiveness index (AI), and Puckorius index (PI) were calculated and analyzed.

The mean temperature, pH, CH, TH, TDS, alkalinity, and EC were 17.79 ± 0.80 °C, 8.08 ± 0.11, 56.34 ± 2.72 mg/L.CaCO3, 140.86 ± 6.81 mg/L.CaCO3, 530 ± 110 mg/L, 181.21 ± 13.65 mg/L, and 840 ± 180 µs/cm, respectively. The mean corrosion and scaling indices, including LI = 0.18 ± 0.12, RI = 7.72 ± 0.14, AI = 12.09 ± 0.11, and finally PI = 7.96 ± 0.10 were obtained.

Based on the obtained data, drinking water in the transmission and distribution network of Rafsanjan has scaling properties. Water scaling and deposition causes problems, such as blockage of water transmission and distribution pipes, reduction of flow rate and increase of pressure drop in the network, and finally increase of water facilities operation costs. Therefore, measures should be considered to control the scaling of water in this region.

Road dust is a group of solid particles that are presented in the urban areas and are originated from both natural and human-induced sources. This study aims to determine concentrations of heavy metals in urban dusts in Behbahan to identify their natural or anthropogenic sources.

In this study, a total of 20 samples were collected from main roads with different land uses, including residential, industrial, and commercial areas in Behbahan city, Khuzestan province.

The results of mineralogy identification showed that calcite, dolomite, quartz, albite, and gypsum were the most identified minerals in dust samples. In addition, heavy metals of As, Co, Cr, Cu, Mn, Fe, Ni, Zn, Pb, Sb, U, Cd, Hg, and Mo were investigated in the collected settled road dust. The results indicated that the level of heavy metals, such as Co and Sb in the places with high traffic load were much higher than other areas. The highest Igeo value for Pb, Cu, and Sb were 1.39, 2.19, 2.46, respectively, suggesting that Pb, Cu, and Sb in the road dust were originated from the anthropogenic sources. Moreover, the results demonstrated that road dust may pose serious health threats to humans (both adults and children).

In this study, the concentration of heavy metals in road dust of Behbahan was investigated. The concentration of heavy metals, such as Cu, Zn, Ni, As, Cr, Pb, U, and Fe in the road dust of the commercial section were much higher than other sections.

Nitrophenol compounds are toxic compounds found in industrial wastewaters. 2,4-dinitrophenol is the most dangerous compound among phenolic compounds. The aim of this study was to evaluate the removal of 2,4-DNP from wastewater by microwaved dried sludge adsorbent.

The results of 2,4-DNP removal were discontinuously obtained by the high performance liquid chromatography (HPLC) at a wavelength of 360 nm with various effective factors, such as contact time, pH, initial concentration of 2,4-DNP, and microwaved sludge dose. Finally, the results were analyzed using the kinetics and isotherm models. The equilibrium time was obtained 120 min. The maximum removal rate was obtained at pH 7.

The findings indicated that the removal efficiency increased by increasing the adsorbent dose and decreasing the 2,4-DNP concentration. It was revealed that the removal of 2,4-DNP by microwaved sludge was 86%. The correlation coefficient value of linear and non-linear regression showed that kinetic studies follow the pseudo-second order model and isotherm studies follow the Freundlich isotherm model. The adsorption method relied entirely on pH and affected the adsorbent area attributes, ionization rate, and Delete percentage. When the pH was high, there was competition for the adsorption sites between hydroxide ions (OH) and 2,4-DNP molecules. At first, the adsorption process was high speed and gradually reached a stable level, because after a while, the adsorption sites become saturated.

As the absorbent dose increases, the efficiency of the adsorption process increases, because larger amounts of adsorbent cause higher adsorption places.

Biodegradation of azo dyes under harsh environmental conditions has been of great interest for the treatment of colored effluents. The present study aims to evaluate Klebsiella quasipneumoniae GT7 for degrading azo dye Carmoisine under extreme pH conditions and high salinity.

The growth profiles of bacteria were compared under different conditions of salinity and pH, using the optical density and viability measurements. Kinetic patterns of decolourization by GT7 were investigated under different concentrations of NaCl and/or pH, through the spectrophotometry method. Moreover, thin layer chromatography (TLC) was used to evaluate the biotransformation of Carmoisine into aromatic amines. Scanning electron microscopy (SEM) was carried out to analyze any morphological changes in bacteria under stress conditions.

GT7 showed OD-based growth and sustainable viability under [NaCl] ≤ 15% and/or initial pH between 3-11. The viable but nonculturable (VBNC) state explained the bacteria's survival under attenuated growth due to bacterial inefficiency to maintain cytoplasmic osmotic balance, vital turgor pressure, and pH homeostasis. Biodecolourization was accomplished during 48h, where Carmoisine was 50mg/l, [NaCl] ≤ 20%, and/or initial was pH 5-11. TLC, OD600nm and pH measurements as well as visual observation of bacterial pellets at the end of the decolourization confirmed biodegradation as the dominant mechanism, except for pH 3, where dye was removed via adsorption to the cell surface. SEM showed morphological alteration of GT7 from rod to coccoid shape as an approach to resist the harsh conditions ratio.

GT7 is shown as an efficient strain for azo dye degradation in harsh environmental conditions.

Perchloroethylene (PCE) is one of the most well-known chlorinated organic compounds recently detected in aqueous environments. The presence of PCE in aquatic ecosystems has caused many health problems and environmental challenges. Therefore, its removal and treatment from aqueous environments are essential.

The electro-Fenton (EF) process was carried out in a cylindrical reactor containing 250 mL contaminated water with PCE. The effects of parameters, including solution pH (3-12), current density (2-10 mA cm-2), H2O2 concentration (20-70 µL H2O2 per 250 mL sample.), PCE concentration (5-50 mg L-1), and electrolysis time (1-15 min) on PCE degradation were investigated. The kinetics and radical’s scavenger of the EF process were examined to detect the exact mechanism of PCE degradation.

The degradation of the PCE of 98.1% was obtained in the optimum condition, including solution pH of 5, the current density of 8 mA cm-2, H2O2 concentration of 50 µL per 250 mL sample, PCE concentration of 15 mg L-1, and electrolysis time of 10 min. The kinetics studies of the EF process indicated that the obtained results were in satisfactory agreement with the first-order model (R2 = 0.9858, Kapp = 0.2822). Also, the addition of ethanol and tertiary butanol caused an inhibiting effect.

The EF process was effectively applied to degrade PCE from polluted water as an efficient technique.  The obtained results indicated that the generation of •OH throughout the EF process was the key mechanism that controlled the EF process.

Electrospun nanomembranes have been used for effective air filtration due to their potential for active surface modification. This study aims to synthesize polyurethane (PU) nanofiber membrane incorporated with different amounts of β-cyclodextrin (β-CD) to capture volatile organic compounds (VOCs) along with aerosol filtration from the air.

First, PU was synthesized by MDI method. A 10 wt% PU solution in DMF/MEK (1:1 wt) was prepared. Various amounts of β-CD powder (0, 1, 2, 3, and 5 wt% of PU) were dispersed in the prepared PU solution. Electrospining process was carried out under determined parameters (20 kV applied voltage, tip-to-collector distance of 10 cm, solution feed, and rate of 1 ml/h). The chemical structure and morphology of the produced samples were assessed by FTIR and SEM, respectively. Finally, air filtration and toluene adsorption of different electrospun membranes were measured.

The highest filtration performance was observed for PU with 1 wt% β-CD nanofiber. Due to increased efficiency (83.13%) and low-pressure drop (∆P = 19 pa), this sample had a considerable quality parameter. The results demonstrated that the membrane loaded with β-CD was able to adsorb hazardous and carcinogenic VOCs. It was confirmed that adding β-CD into PU improves the adsorption capacity due to forming a π complex and having a different tendency against capturing a variety of VOCs.

The study results revealed that the PU nanofiber incorporated with β-CD, along with the ease of regeneration, can make them attractive for air filtration and VOCs adsorption.