Recycled Synthetic Polymer-Based Electrospun Membranes for Filtering Applications

Synthetic polymers have been widely applied in various commercial and household applications owing to their fascinating properties of low-cost, lightweight, and processability. However, increasing population and living standards and rising demand for non-biodegradable polymers have led to the accumulation of plastic pollution resulting in the current environmental crisis. Current waste management methods such as landfilling or incineration do not solve these environmental issues. On the other hand, recycling plastic waste is the most valuable strategy for dealing with waste as raw material for high-value products. One of such products is filter membranes. Polymer fiber membranes as masks in pandemics have been one of the most sought-after products in recent years. Some types of plastic waste became a material source for the development of filter materials, which could contribute to the protection of human health. Utilizing the simple, cheap, and industrially available technological solution is also needed. Given the number of advantages, electrospinning is such a beneficial solution. The electrospun polymer waste-based membranes show excellent filtration performance and can carry many other functionalities. Therefore, this review article presents a brief overview of electrospun nanofibrous membranes based on synthetic plastic waste and summarizes the filtration performance of such membranes. This review will discuss the future perspectives of electrospun membranes as well

Influence of variable weather on incident solar radiation and its spectral composition in the Ostrava region, Czech Republic

Incident solar radiation is influenced by many factors, including distance from the equator, altitude, time of year, and season. Absorption of radiation and its scattering are connected with the properties of atmospheric compounds. Cloud cover and air pollution are connected with tropospheric properties. Using our data, the influence of weather changes on the dose of solar irradiance reaching the Earth’s surface and its spectral composition are described. Solar radiation components were measured continuously by a system of sensors situated in the Botanical Garden of the University of Ostrava, Czech Republic. Data for 2014 were chosen for analyses. Days were divided into categories of sunny days and cloudy days according to weather conditions and daily radiation patterns. Percent differences in received solar radiation between sunny and cloudy days were calculated for eight months (Jan, Feb, Mar, Jun, Jul, Aug, Sep, and Dec). Differences in received solar radiation between clean and polluted days were calculated for sunny and cloudy days in December 2014. Mean incident solar radiation during cloudy days was reduced by 61% from the value for sunny days (in summer months) and by 64% from the value for sunny days in winter months. The largest influence of clouds on received solar radiation was during September and the smallest was during June. There was a reduction in incident solar radiation caused by the atmospheric pollutant PM10 during winter months. This reduction amounted to 10% during sunny days and 21% during cloudy days for December 2014. Clouds significantly reduced incident solar radiation as did the air pollutant PM10, but there were probably other factors also contributing to the reduction in incident solar radiation