Bentonite sample
enriched in organic matters (oil shale) was functionalized
with −SO3H sulfonated carbonaceous bentonite (S-CB)
by sulfonation process as a low-cost and effective acidic catalyst
for the transesterification spent sunflower oil (SFO). The sulfonation
effect was followed by several analytic techniques including X-ray
diffraction, Fourier transform infrared, and scanning electron microscopy
analysis. The catalytic performance of the sulfonated product was
evaluated based on a statistical design which was built according
to the response surface methodology and the central composite rotatable
design. Using the S-CB acidic catalyst in the transesterification
of spent SFO resulted in an actual biodiesel yield of 96% at studied
conditions of 85 min at reaction interval, 50 °C as temperature,15:1
as methanol/oil ratio, and 3.5 wt % as S-CB loading. Moreover, the
optimization function suggested enhancement to obtained yield up to
97.9% by selecting the values of temperature at 62 °C, the time
at 98.5 min, the methanol/SFO ratio at 14.4:1, and S-CB loading at
3.4 wt %. The technical evaluation of the SFO biodiesel reflected
the suitability of the product to be used as biofuels according to
international standards. The kinetic behavior of the SFO transesterification
reaction over S-CB is of pseudo-first order properties and of low
activation energy. Finally, the synthetic S-CB as a solid acidic catalyst
is of significant reusability and was reused five times with remarkable
biodiesel yields.
A taxonomic revision of the genus Amaranthus (Amaranthaceae) in Saudi Arabia, based on both field surveys and examination of harbarium specimens, is here presented. Collected exsiccata are kept the Herbaria PNUH and RO. An extensive literature was also analysed. Sixtheen non-hybrid taxa (twelve species) are recognized. Data about nomenclature (accepted names, main synonyms, and types), morphology, chromosome number, chorology (for native taxa) or alien status (for exotic taxa), occurrence in Saudi Arabia, ecology (preferential habitat, phenology, elevation), and taxonomic annotations are provided for each taxon. A diagnostic key is proposed. Four taxa (A. graecizans subsp. graecizans, A. graecizans subsp. sylvestris, A. graecizans subsp. thellungianus, and A. sparganicephalus) are native, whereas the other ones are to be considered aliens. A. dubius and A. blitoides var. blitoides are new for the national flora. Furthermore, the name A. sparganicephalus is neotypified on a specimen deposited at E and a nomenclatural change (A. blitum var. nanus comb. nov.) is proposed.
In this study, we have opened a great route to fabricate a high-performance nanocomposite for various functional applications based on the composite of a natural stone. A clay sample (black shale (B.Sh)) was collected from the Abu-Tartur area in Egypt. The black shale was organically modified with organic materials in our laboratory, which is called organic-black shale (O-B.Sh). The samples were characterized by XRD, FTIR, SEM, and XRF. These techniques confirmed that the samples have multi-oxide phases with approximately SiO2 at 54.1%, Al2O3 at 24.73%, Fe2O3 at 6.02%, K2O at 1.12%, MgO at 1.09%, and Na2O of 0.09%, as calculated by XRF. The two samples were applied to the adsorption processes of the radioactive technetium materials, which have been used for the medical treatment of the cancer institute of upper Egypt. The adsorption processes were performed at various concentrations of the radioactive material and various amounts of clay samples. The as-collected B.Sh sample showed an adsorption activity of 65%, however, the organically modified materials showed a high adsorption rate toward technetium reaches to 100% in a very short time, and without any further process. The present collected materials are very promising to withdraw the radioactive materials from the saline solution to save human and environmental health. We believe that these multi-compound composites may open a new approach for creating new fabric composites with high performance toward various applications.
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