margherita ferrante

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.

Cesium radioactive isotopes (134Cs and 137Cs) are dangerous to human health due to their long half-life and high solubility in water. Nuclear experiments, wars, and nuclear plant accidents have been the main sources of Cs release into the environment. In recent years, several methods have been introduced for the elimination of Cs radioactive isotopes from contaminated water. This study provides an overview of the available published articles (2008–2016) regarding the remediation of waters polluted by Cs isotopes. The maximum adsorption capacity (MAC) of Cs isotopes corresponded to natural chabazite (273.24 mg Cs/g adsorbent), hollow Prussian blue (PB) nanoparticles (262 mg Cs/g adsorbent), and Prussian blue implemented non-woven fabric (260 mg Cs/g adsorbent). Using natural chabazite and PB adsorbents, along with another adsorbent (PB graphene oxide hydrogel), Cs radioactive isotopes can be effectively removed from the aqueous solutions.