Asmaa El-Mekawy

Climate change due to the air pollution is actually one of the largest environmental challenges worldwide. Preparation and development of stable and highly efficient nanocomposite membranes remain a significant goal because of its enormous importance of controlling the environment. This study investigated a simple synthesis of poly (vinyl alcohol)/graphene oxide (PVA/GO) nanocomposite membrane for air pollutant remediation. The chemical and physical structures, morphologies, and conductivities were investigated as a function of the GO loading. The objective of the present study was to evaluate the efficiency of novel PVA/GO membranes in the removal of both formaldehyde (FA) as a pollutant VOCs model and SO₂ as a model of greenhouse gases. Furthermore, the purpose of this study is to identify good predictors for selecting the appropriate optimal GO content in GO/PVA nanocomposites that exhibit higher air pollutant removal performance as well as design an economical GO/PVA nanocomposite air purification system for removal of the air pollutants in the field. To our knowledge, field application of GO/PVA nanocomposite volatile organic compound (VOCS) filters and control of SO₂ gas pollutants from indoor air has not yet been realized. The nanocomposite membranes with an optimum GO content exhibited higher removal performance for the FA gas pollutant, this enhancement reached 90% in the laboratory scale. However, during the application in the field, it showed 75% FA removed from the indoor air. These new nano-membranes reveal also wide efficiencies of SO₂ removal (80%) when applied in the field. Therefore, this filter system proved an excellent efficacy in the removal of air pollutants and could be more promising in various industrial applications.

Ancient archaeological buildings are witness on human civilization and cultures. Saving and the conservation of cultural heritage is an urgent priority in Egypt and worldwide. ElManial palace and museum is one of the most important Egyptian ancient archaeological buildings and has great historical and cultural value due to the presence of personal valuable property and memorabilia of Prince Mohammed Ali Tewfik objects which reflecting the settings and lifestyle of the late 19th and early 20th century Egyptian royal prince and heir apparent. Unfortunately the palace is situated in very crowded and polluted place, so thus study was done for measuring the effect of pollutants on the palace and monuments collections on it. RH%, temperature, particulate matter (PM) and its ionic species and gaseous air pollutants (sulphur dioxide, nitrogen dioxide, ammonia, hydrogen sulfide and formaldehyde) were measured inside and outside the museum. The annual mean concentration of SPM in outdoor and reception hall exceeded both national and international limits. A/C ratios for all locations were greater than one, indicating that SPM were in acidic state, which had hazard effect on the palace and its heritage constituents. HCHO and NH3 gases were high compared to other studies. SO2 and NO2 gases were more than international limits which form a critical danger on the palace.

Greater Cairo (Egypt) is a megalopolis where the studies of the air pollution events are of extremely high relevance, for the geographical-climatological aspects, the anthropogenic emissions and the health impact. While preliminary studies on the particulate matter (PM) chemical composition in Greater Cairo have been performed, no data are yet available on the PM’s toxicity. In this work, the in vitro toxicity of the fine PM (PM_2.5) sampled in an urban area of Greater Cairo during 2017–2018 was studied. The PM_2.5 samples collected during spring, summer, autumn and winter were preliminary characterized to determine the concentrations of ionic species, elements and organic PM (Polycyclic Aromatic Hydrocarbons, PAHs). After particle extraction from filters, the cytotoxic and pro-inflammatory effects were evaluated in human lung A549 cells. The results showed that particles collected during the colder seasons mainly induced the xenobiotic metabolizing system and the consequent antioxidant and pro-inflammatory cytokine release responses. Biological events positively correlated to PAHs and metals representative of a combustion-derived pollution. PM_2.5 from the warmer seasons displayed a direct effect on cell cycle progression, suggesting possible genotoxic effects. In conclusion, a correlation between the biological effects and PM_2.5 physico-chemical properties in the area of study might be useful for planning future strategies aiming to improve air quality and lower health hazards.

A batch process was used to evaluate the potential of regeneration of spent activated carbon (AC) by solvent extraction technique with synergetic to ultra-sonication. Experiments were undertaken as a function of the initial concentration of toluene. Freundlich and Langmuir models were used to study the adsorption isotherms and the data well fitted the Langmuir expression. The maximum adsorption capacities of toluene were found to be 0.108 µg/g activated carbon for Type-I Langmuir. Extraction of the used AC by both methanol solvent and ultrasonic radiation yielded up to 95% reactivation of the spent AC in the first run. Nearly up to 88 % recovery of activity could be achieved after further regeneration and reusing of the spent AC. The results indicate that the coupling of solvent extraction with ultrasonic waves in the AC treatment is comparable and perhaps superior to the conventional regeneration techniques in many cases. This is mainly due to the single step process applied which is less energy consuming; in addition to the nearly comprehensive recovery of the adsorptive capacity of spent AC.