Ion Untea

Climate change: some insights from mean surface temperature statistics

The actual way to tackle with climate change – the setting of a 2°C limit for the increase of the global mean surface temperature (MST) value – is rather unsafe as, at planet scale, the warming is far from uniform. The latitude zones are characterized not only by different climates, but also by different rates of climate parameters modification. Computer analysis of statistical data for more than 100 years shows that the warming rates of the MST and current temperature anomalies are approximately double when one compares the land/ocean areas or the 64N–90N band to the ones near the equator line. Therefore, the zone differences should be taken into consideration as a useful environment indicator for the setting of sustainability targets. The most intense rise of the surface temperature is present and will continue at increased rate in the zone comprising the Arctic area. Statistical treatment also shows a negative feedback of the planet, opposing the global warming process. The polar zones are the ones with lesser abatement tendency. The other areas, despite differences in heating rates, present almost similar values for the attenuation index.

Photocatalytic membrane system: Obtaining procedure and environmental application

This study reveals the synthesis of a membrane system by a simple and efficient procedure. The conditions used for preparing a membrane system to a substrate have a great effect on its performance. The determination of a suitable immobilisation procedure for specific application becomes complicated with the methods developed over the years. A hybrid coating of fiberglass served as substrate to obtain a photocatalytic system. The working procedure is based on the immersion of fiberglass in suspension consisting of sodium silicate solution and titanium dioxide. The new synthesised membrane system was characterized using X-ray spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. The present study is focused on the procedure for obtaining new materials for environmental applications and performance evaluation of membrane system in advanced oxidation processes. The photocatalytic activity of the membrane system was evaluated through the oxidation process of organic compounds from wastewater. A synthetic solution by 4-chlorophenol was used as test substance. Removal of phenols compounds from wastewater is extremely important from an environmental perspective.

Photo-catalytic oxidation of 4-chlorophenol using TiO 2 -functionalized membranes

This work presents a hybrid method for advanced removal of 4-chlorophenol from water by combining the membrane and photo-catalytic processes. The hybrid method consists of photo-catalytic oxidation procedure using a photo-catalytic reactor equipped with a TiO2-functionalized membrane obtained by the sol-gel method. The photo-catalytic activity is dependent on the alcohol solvent type used for synthesis, which determines the TiO2 deposition and characteristics. At higher reaction time, the regenerated cellulose membrane becomes slightly unstable due to UV radiations and a strong oxidizing potential of the reaction medium.