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Wyszukujesz frazę "Fe3O4" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Halloysite composites with Fe3O4 particles: the effect of impregnation on the removal of aqueous Cd(II) and Pb(II)
Autorzy:
Maziarz, Paulina
Matusik, Jakub
Powiązania:
https://bibliotekanauki.pl/articles/127631.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
Fe3O4 particles
halloysite
adsorption
Cd(II)
Pb(II)
Opis:
In this study, halloysite-Fe3O4 composites were synthesized by a chemical-precipitation method to facilitate magnetic separation of the sorbents from aqueous solution. The research focused on the effect of Fe3O4 phase on the halloysite sorption properties. The X-ray diffraction (XRD) results confirmed successful deposition of Fe3O4 particles on a halloysite surface. They showed that the coating with Fe3O4 particles enhanced the halloysite adsorption affinity toward Cd(II) and Pb(II). The highest adsorption capacity was determined for the composites having 10% of the surface deposited with Fe3O4. In this case, the adsorption capacity for Cd(II) and Pb(II) was 33 and 112 mmol•kg-1, respectively. The point of zero charge (pHPZC) and desorption results indicated that the removal mechanism of metals is mainly related to chemisorption involving reaction with hydroxyls of either halloysite or Fe3O4 phase. The ion exchange is of limited importance due to the low cation exchange capacity (CEC) of halloysite - Fe3O4 composites.
Źródło:
Mineralogia; 2017, 48, 1/4; 107-126
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Magnetite Oxide Nanoparticles and Tungsten Oxide Nanoparticles on Phosphate Removal from Aqueous Solutions
Autorzy:
EL-Baz, Amro
Mokhtar, Mona
Abdo, Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/24201790.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
phosphate removal
nanoparticles
Fe3O4 NPs
WO3 NPs
adsorption
desorption
Opis:
Phosphate (P) removal from aqueous solutions were studied by a new mineral adsorbent, tungsten (VI) oxide (WO3) nanoparticles (NPs), which has not been the subject of much research in the field of removing P contaminants from agricultural wastewater. In this paper, P was removed from aqueous solutions by a new mineral adsorbent, WO3 NPs and it was compared with magnetite (iron IV) oxide (Fe3O4) nanoparticles (NPs) under the same ambient operating conditions i.e., The influence of the dosage of adsorbents, initial P concentration, contact time, pH and temperature. The values that achieved the best removal were recorded. It was concluded that the best limits for pH were at 2–3, contact time at 40 minutes, temperature at 45 °C and adsorbent dose at 1.0 g/L. Best results of the variables were applied on samples of real agricultural wastewater, which achieved removal ratio of 77.3% and 75.42% for Fe3O4 and WO3 NPs, respectively. SEM, EDX and FTIR images and analyses were conducted to describe the characteristics of nano-adsorbents used before and after P adsorption in aqueous solutions. The P adsorption kinetics for aqueous solutions were examined by fitting results of the experiment to both the first & second pseudo-kinetically models. The outcome indicated that kinematic data fit better with pseudo-second-order kinetic models. Moreover, the information captured from equilibrium adsorption was analyzed using isothermal methods (by Langmuir & Freundlich Forms). Their results showed that the Freundlich form is considered more suitable than Langmuir form in analyzing the biosorption of P ions. The thermodynamic demeanor of P adsorption by Fe3O4 and WO3 NPs was analyzed and evaluated, and the thermodynamic data analyses confirmed the process of P adsorption was spontaneous. The ΔG° value was negative, while ΔH° and ΔS° values found to be positive, which means that the adsorption of P was a spontaneous, random and endothermic operation. In general, Fe3O4 and WO3 nanoparticles had a high efficiency in removing phosphate from water. In addition, WO3 NPs has been identified as one of the most promising adsorbents due to its rapid and effective adsorption of pollutants.
Źródło:
Journal of Ecological Engineering; 2023, 24, 3; 287--303
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Covalent immobilization of laccase on Fe3O4-graphene oxide nanocomposite for biodegradation of phenolic compounds
Autorzy:
Rouhani, Shamila
Azizi, Shohreh
Maaza, Malik
Mamba, Bhekie
Msagati, Titus A. M.
Powiązania:
https://bibliotekanauki.pl/articles/2032944.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phenol
adsorption
biodegradation
Fe3O4
Trametes versicolor
laccase
fenol
adsorbcja
biodegradacja
lakaza
Opis:
Laccase from Trametes Versicolor (E.C. 1.10.3.2) was immobilized on the Fe3O4–graphene hybrid nanocomposite through the covalent attachment method (Lac/Fe3O4/GO). The effect of immobilization conditions on the activity and recovered activities such as contact time, the concentration of glutaraldehyde and enzyme was evaluated. The recovered activity of the immobilized laccase on the Fe3O4–graphene oxide nanocomposite was ca. 86%. Immobilized laccase unlike free laccase retained the activity and exhibited higher resistance to temperature and pH changes and also improved storage and thermal stability. Approximately 70% of relative activity for immobilized laccase was remained after being incubated for 2 h at 55 °C, but free laccase only remained 48%. Immobilized laccase retained 88% of initial activity after storage for 20 days, however, the free laccase only 32%. Finally, Lac/Fe3O4/GO capability was evaluated by the oxidation of phenol, p-chlorophenol, and 2,4-dichlorophenol. Lac/Fe3O4/GO was characterized by SEM, EDX, FT-IR, and AGFM.
Źródło:
Environment Protection Engineering; 2021, 47, 1; 85-99
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of Calcium Oxide from Green Mussel Shell with Iron Oxide as a Potential Adsorbent for the Removal of Iron and Manganese Ions from Acid Mine Drainage
Autorzy:
Purwaningrum, Widia
Hasanudin, Hasanudin
Rachmat, Addy
Riyanti, Fahma
Hariani, Poedji Loekitowati
Powiązania:
https://bibliotekanauki.pl/articles/2202252.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
CaO/Fe3O4
green mussel shell
adsorption
iron
manganese
acid mine drainage
Opis:
Acid mine drainage (AMD) has the characteristics of high heavy metal ion content and low pH. This study aimed to synthesize the CaO/Fe3O4 composite for the adsorption of iron and manganese ions from acid mine drainage. CaO was synthesized from the shells of green mussels (Perna viridis). The CaO/ Fe3O4 composites were characterized using XRD, BET surface area, SEM-EDS, and VSM. The functional groups of the composite before and after adsorption were analyzed using FTIR. The adsorption of Fe(II), Fe(III), and Mn(II) ions was carried out with the batch method to determine the effect of pH, contact time, and initial concentration of metal ions. The CaO/ Fe3O4 composite has magnetic properties, as indicated by the saturation magnetization value of 65.49 emu/g. The Langmuir and Freundlich isotherm models were used to describe the adsorption isotherm of the composite for Fe(II), Fe(III), and Mn(II) ions. Investigations were also conducted on adsorption kinetics, including pseudo-first-order and pseudo-second-order, as well as adsorption thermodynamics comprising free energy, enthalpy, and entropy. Pseudo-first-order and Langmuir isotherms are suitable to describe the adsorption of Fe(II), Fe(III), and Mn(II) ions with adsorption capacities of Fe(III) > Fe(II) > Mn(II). Moreover, the adsorption of all ions using the composite occurred spontaneously. The removal effectiveness for Fe and Mn ions from AMD using CaO/ Fe3O4 composite, reached 90.41 and 97.59%, respectively, in volume 100 mL AMD, composite mass 0.4 g, and a contact time of 60 minutes.
Źródło:
Journal of Ecological Engineering; 2022, 23, 11; 188--201
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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