233 research outputs found
Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees
email Suzanne orcd idCopyright: © 2015 Williams et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
“Microwave approach and thermal decomposition: A sustainable way to produce ZnO nanoparticles with different chemo-physical properties”
An easy synthesis for preparing bio-based hybrid adsorbent useful for fast adsorption of polar pollutants
For the first time, γ-Al2O3 and Bio-Based Substances (BBS) hybrids (A-BBS) were prepared through a simple electrostatic interaction occurring between alumina, used as a support, and BBS (Bio-Based Substance from composted biowastes) carrying positive and negative charges, respectively. We evaluated the optimal amount of BBS to be immobilized on the support and the stability of the resulting A-BBS in order to use this novel hybrid material as an adsorbent for the removal of polar pollutants. Characterization was carried out by X-Ray Diffraction (XRD) for evaluating the crystal structure of the support, Fourier transform infrared spectroscopy (FT-IR) to evidence the presence of BBS on the hybrid material, thermogravimetric analysis (TGA) to measure the thermal stability of the hybrid materials and quantify the BBS amount immobilized on the support, N2 adsorption at 77 K for the evaluation of the surface area and porosity of the systems, Zeta potential measurements to evaluate the effect of BBS immobilization on the surface charge of the particles and choose the substrates possibly interacting with them. Firstly, we tested the adsorption capability of three samples differently coated with BBS toward cationic species considering various adsorbate/adsorbent ratio. Crystal Violet (CV) was chosen as model pollutant to compare the performance of the hybrid materials with those of other materials described in the literature. The adsorption data were modeled by Langmuir and Freundlich adsorption isotherms. Then, we studied the adsorption capability of the developed material towards molecules with different structures; for this purpose, two contaminants of emerging concerns (carbamazepine and atenolol) were tested. The results indicate that A-BBS could be applied in wastewater treatment for the removal of a significant amount of polar species. In addition, a comparison with literature data concerning CV adsorption was carried out in order to evaluate the environmental impact of synthetic routes used to prepare different adsorbents
Novel magnetite nanoparticles coated with waste sourced bio- based substances as sustainable and renewable adsorbing materials
This study examines the possibility of using bio-based product isolated from urban solid wastes as a material for environmental technological applications. To this end, Fe3O4 nanoparticles coated with different amounts of soluble bio-based products (SBO) were synthesized as low-cost nanoadsorbent for the removal of pollutants in wastewater. Particles of 10 nm diameter with Fe3O4 core and SBO shell were obtained. The concentration of SBO employed in the synthesis had no effect on the size and structure of the NPs, but ruled the pHPZC and aggregation of the nanoparticles in water. The cationic dye crystal violet (CV) was used as a model pollutant to test the adsorption capacity of the nanoparticles. The results indicated that both the medium pH and NP dosage were significant parameters to enhance the removal of CV. The results contribute to the studies which show how wastes can become a source of revenue through the industrial exploitation of their chemical value.Fil: Magnacca, Giuliana. Università di Torino; ItaliaFil: Allera, Alex. Università di Torino; ItaliaFil: Montoneri, Enzo. Università di Torino; ItaliaFil: Celi, Luisella. Università di Torino; ItaliaFil: Benito, Damián Ezequiel. Universidad Nacional de La Plata. Laboratorio de Investigación y Desarrollo de Métodos Analíticos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Gagliardi, Leonardo Gabriel. Universidad Nacional de La Plata. Laboratorio de Investigación y Desarrollo de Métodos Analíticos; ArgentinaFil: Martire, Daniel Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Gonzalez, Monica Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Carlos, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin
A Way to Close the Loop: Physicochemical and Adsorbing Properties of Soybean Hulls Recovered After Soybean Peroxidase Extraction
Enhanced fabrication of silicon carbide membranes for wastewater treatment: From laboratory to industrial scale
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Green surface modification of polyvinyl alcohol fibers and its application for dye removal using Doehlert experimental design
Dissolved organic carbon retention by coprecipitation during the oxidation of ferrous iron (EGU2018-3906)
Although the importance of Fe (hydr)oxides for soil organic matter (OM) stabilization and C retention by surface adsorption is well known, only recently has coprecipitation been recognized as an important process responsible for C storage in hydromorphic soils, such as rice paddy soils. Under periodic fluctuations in redox conditions the interaction between dissolved organic carbon (DOC) and Fe (hydr)oxides may not only involve organic coatings
on mineral surfaces, but also Fe-DOC coprecipitates that form during the oxidation of soil solutions containing important amounts of DOC and Fe2+.
The aim of this work was to provide new insights into the mechanisms involved, and the amount and selectivity of C retained during the coprecipitation process. A series of Fe-OM associations with increasing C loading was synthesized at pH 6 by surface adsorption or coprecipitation (oxidation of ferrous iron) utilizing rice-straw derived dissolved organic matter. The kinetics of Fe2+ oxidation and complexation, and the total and selective retention of DOC during the coprecipitation process were evaluated. Moreover, synthesized associations, as well as a field coprecipitate collected in situ from a paddy soil, were studied by X-ray diffraction, N2 gas adsorption-desorption isotherms, electrophoretic mobility measurements and thermogravimetric analyses. Coprecipitation resulted in higher organic C contents (49-213 mg g-1) with respect to adsorbed systems (18-47 mg g-1), and favoured the inclusion of OM within highly aggregated associations having particularly low BET specific surface areas. Coprecipitates sampled in situ also showed a similar retention of organic C confirming that this process may contribute significantly to the OM stabilization in paddy topsoils. The mechanisms involved in the retention of straw-derived DOM during coprecipitation were shown to be strongly dependent on C/Fe ratio of the solution. Although the overall coprecipitation process was highly selective for aromatic constituents, initial complexation of Fe2+ and precipitation as C-rich metal salts involved the selective interaction with aliphatic carboxylic constituents. The contribution of the latter mechanism to total C retention during coprecipitation was shown to increase with increasing solution C/Fe ratios. These aliphatic complexes formed during coprecipitation may play an important, though often underestimated, role in C stabilization in hydromorphic. The process-related selectivity of specific constituents of DOM during coprecipitation highlights the involvement of specific mechanisms, i.e. complexation, adsorption, salt precipitation, while ruling out non-selective, physical occlusion of OM within the forming coprecipitat
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