14 documents found, page 1 of 2
Communication - On the possibility of Fe electrowinning from hematite suspensio...
Lopes, Daniela V.; Frade, Jorge R.; Kavaleuski, Andrei V.Iron electrowinning offers a greener path for steel production. While alkaline media has received the most significant attention, the acidic media declined due to low Faradaic efficiency and difficulties imposed by fragile deposits. This study proposes, for the first time, prospects for acidic Fe electrowinning using a mixed-acid electrolyte (H2SO4+C2H2O4), comparing the deposition from hematite suspensions and...
Phosphorus removal from urban wastewater through adsorption using biogenic calc...
Santos, Andreia F.; Lopes, Daniela V.; Alvarenga, Paula; Gando-Ferreira, Licínio M.; Quina, Margarida J.Phosphorus (P) removal from urban wastewater is increasingly relevant in the wastewater treatment sector. The present work aims to contribute to the study of the adsorption process as a P removal technology. Biogenic calcium carbonate from industrial eggshell waste prepared by milling and calcination was used as an adsorbent. Batch adsorption experiments were conducted using real wastewater with 40 mg P/L (orth...
Exploring the high-temperature thermoelectric performance of la-substituted Ca3...
Constantinescu, Gabriel; Lopes, Daniela V.; Amir Khizi, Parisa; Vieira, Miguel A.; Kavaleuski, AndreiIt is well-known that the electrical properties of the Ca3Co4O9 thermoelectric (TE) compound are strongly influenced by the valence of the substituting cation, while its solubility and “functional” impact depend largely on the preparation and/or processing methods used. Furthermore, this material’s hybrid crystal structure allows for different cation substitutions in/from different sublattices. This research wo...
Catalytic O2-steam gasification of biomass over Fe2-xMnxO3 oxides supported on ...
Ruivo, Luis C. M.; Gomes, Helena; Lopes, Daniela V.; Yaremchenko, Aleksey; Vilas-Boas, Catarina; Tarelho, Luís A. C.; Frade, Jorge R.In the present study, catalytic gasification of biomass was investigated by incorporation of a supported Fe2-xMnxO3 catalyst into the freeboard zone of a bubbling fluidized bed gasifier. The material was processed by combining incipient wetness impregnation with microwave-assisted firing methods. These catalysts were characterized by elemental, structural and microstructural analyses, and redox testing by therm...
Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite m...
Sergiienko, S.A.; Tobaldi, David M.; Lajaunie, Luc; Lopes, Daniela V.; Constantinescu, Gabriel; Shaula, A.L.; Shcherban, Nataliya D.MXenes, a family of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides based on earth-abundant constituents, are prospective candidates for energy conversion applications, including photocatalysis. While the activity of individual MXenes towards various photocatalytic processes is still debatable, these materials were proved to be excellent co-catalysts, accelerating the charge separatio...
Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic F...
Constantinescu, Gabriel; Mikhalev, Sergey M.; Lisenkov, Aleksey D.; Lopes, Daniela V.; Sarabando, Artur R.; Ferro, Marta C.; Silva, Tiago F. daThis work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar...
Exploring the high-temperature electrical performance of Ca3-xLaxCo4O9 thermoel...
Constantinescu, Gabriel; Rasekh, Shahed; Amirkhizi, Parisa; Lopes, Daniela V.; Vieira, Miguel A.; Kovalevsky, Andrei V.; Diez, Juan C.; Sotelo, AndresAliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical prop-erties and the solubility, and impact of the substituting cation also depends largely on the prepara-tion and processing method. It is also well-known that the monoclinic symmetry of this material’s composite crystal structure allows for a significant hole transfer from the rock salt-type Ca2CoO3 buffer layers to the hex...
Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic F...
Constantinescu, Gabriel; Mikhalev, Sergey M.; Lisenkov, Aleksey D.; Lopes, Daniela V.; Sarabando, Artur R.; Ferro, Marta C.; Silva, Tiago F. daThis work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar...
Exploring the high-temperature electrical performance of Ca3−xLaxCo4O9 thermoel...
Constantinescu, Gabriel; Rasekh, Shahed; Amirkhizi, Parisa; Lopes, Daniela V.; Vieira, Miguel A.; Kovalevsky, Andrei V.; Diez, Juan C.; Sotelo, AndresAliovalent substitutions in Ca3Co4O9 often result in complex effects on the electrical properties and the solubility, and impact of the substituting cation also depends largely on the preparation and processing method. It is also well-known that the monoclinic symmetry of this material’s composite crystal structure allows for a significant hole transfer from the rock salt-type Ca2CoO3 buffer layers to the hexag...
Alkaline electrochemical reduction of a magnesium ferrospinel into metallic iro...
Lopes, Daniela V.; Lisenkov, Aleksey D.; Sergiienko, Sergii A.; Constantinescu, Gabriel; Sarabando, Artur; Quina, Margarida J.; Frade, Jorge R.The electrochemical reduction of iron oxides in alkaline media arises as a novel approach for ironmaking and iron-rich waste valorisation. Strong advantages and attractive aspects of alkaline electroreduction include lower electric energy consumption, absence of CO2 emissions, and non-polluting valuable by-products such as H2 and O2. Another potential advantage originates from the compatibility of this concept ...