The multiple modes of SARS-CoV-2 transmission including airborne, droplet, contact, and fecal–oral transmissions that cause coronavirus disease 2019 (COVID-19) contribute to a public threat to the lives of people worldwide. Herein, different databases are reviewed to evaluate modes of transmission of SARS-CoV-2 and study the effects of negative pressure ventilation, air conditioning system, and related protection approaches of this virus. Droplet transmission was commonly reported to occur in particles with diameter >5 µm that can quickly settle gravitationally on surfaces (1–2 m). Instead, fine and ultrafine particles (airborne transmission) can stay suspended for an extended period of time (≥2 h) and be transported further, e.g., up to 8 m through simple diffusion and convection mechanisms. Droplet and airborne transmission of SARS-CoV-2 can be limited indoors with adequate ventilation of rooms, by routine disinfection of toilets, using negative pressure rooms, using face masks, and maintaining social distancing. Other preventive measures recommended include increasing the number of screening tests of suspected carriers of SARS-CoV-2, reducing the number of persons in a room to minimize sharing indoor air, and monitoring people’s temperature before accessing a building. The work reviews a body of literature supporting the transmission of SARS-CoV-2 through air, causing COVID-19 disease, which requires coordinated worldwide strategies.

In this study, at first were prepared novel multi-walled carbon nanotubes modified with catalytic nanoparticles of iron oxide and silver (MWCNTs-Fe₃O₄/Ag) by mixing the magnetic particles. Due to their excellent absorption and desorption capability towards hydrophobic compounds, the magnetic MWCNTs were used as adsorbent of magnetic solid-phase extraction (MSPE) to extract phthalate acid esters (PAEs). Our results showed the highest concentration of phthalate esters of bis(2-ethylhexyl)phthalate (DEHP) which is much higher than the standard level in the four samples (6766.6, 9201, 9301.6, and 14,008 ng/L). Finally, the established MSPE-GC/MS method was successfully applied to the determination of PAEs from carbonated soft drinks and the MSPE-GC/MS method developed in current study provides a new option for the detection of PAEs from carbonated soft drinks with complex matrices.

Discharge of heavy metals such as hexavalent chromium (Cr (VI)) and nickel (Ni (II)) into aquatic ecosystems is a matter of concern in wastewater treatment