9 documents found, page 1 of 1
Recovery of Nd3+ and Dy3+ from E-Waste Using Adsorbents from Spent Tyre Rubbers...
Nogueira, Miguel; Matos, Inês; Bernardo, Maria; Pinto, Filomena; Fonseca, Isabel Maria; Lapa, NunoABSTRACT: This paper investigates the use of spent tyre rubber as a precursor for synthesising adsorbents to recover rare earth elements. Through pyrolysis and CO2 activation, tyre rubber is converted into porous carbonaceous materials with surface properties suited for rare earth element adsorption. The study also examines the efficiency of leaching rare earth elements from NdFeB magnets using optimised acid l...
Valorisation of spent tire rubber as carbon adsorbents for Pb(II) and W(VI) in ...
Bernardo, Maria; Lapa, Nuno; Pinto, Filomena; Nogueira, Miguel; Matos, Inês; Ventura, Márcia; Ferraria, Ana Maria; Rego, Ana Maria Botelho doABSTRACT: Spent tire rubber-derived chars and their corresponding H3PO4 and CO2-activated chars were used as adsorbents in the recovery of Pb(II) ion and (W(VI)) oxyanion from synthetic solutions. The developed chars (both raw and activated) were thoroughly characterized to have insight about their textural and surface chemistry properties. H3PO4-activated chars presented lower surface areas than the raw chars ...
Cr(III) dynamic removal in a fixed-bed column by using a co-gasification char
Dias, Diogo; Bernardo, Maria; Pinto, Filomena; Fonseca, Isabel Maria; Lapa, NunoABSTRACT: A char (GC) obtained from the co-gasification of rice husk and polyethylene was used in a fixed-bed column with continuous flow for Cr(III) removal assays from synthetic and industrial wastewaters. For comparison purposes, a commercial activated carbon (CAC) was also used. The best experimental conditions in the continuous removal assays were the following ones: Cr(III) inflow concentration = 5 mg L-1...
Cr(III) dynamic removal in a fixed-bed column by using a co-gasification char
Dias, Diogo; Bernardo, Maria; Pinto, Filomena; Fonseca, Isabel Maria; Lapa, NunoABSTRACT: A char (GC) obtained from the co-gasification of rice husk and polyethylene was used in a fixed-bed column with continuous flow for Cr(III) removal assays from synthetic and industrial wastewaters. For comparison purposes, a commercial activated carbon (CAC) was also used. The best experimental conditions in the continuous removal assays were the following ones: Cr(III) inflow concentration = 5 mg L-1...
Highly efficient porous carbons for the removal of W(VI) oxyanion from wastewaters
Dias, Diogo; Don, Davide; Jandosov, Jakpar; Bernardo, Maria; Pinto, Filomena; Fonseca, Isabel Maria; Sanches, André; Caetano, P. S.; Lyubchyk, SvitlanaABSTRACT: Pyrolysis chars derived from rice wastes were chemically activated and used in W(VI) oxyanion adsorption assays in synthetic and mining wastewaters. For comparison purposes, a commercial activated carbon (CAC) was also used. Different experimental conditions were tested in the adsorption assays: solid/liquid ratio (S/L), initial pH, contact time, and initial W concentration. The porous carbon P2C+KOH ...
Cr(III) removal from synthetic and industrial wastewaters by using co-gasificat...
Dias, Diogo; Lapa, Nuno; Bernardo, Maria; Ribeiro, W.; Matos, Inês; Fonseca, Isabel Maria; Pinto, FilomenaABSTRACT: Blends of rice waste streams were submitted to co-gasification assays. The resulting chars (G1C and G2C) were characterized and used in Cr(III) removal assays from a synthetic solution. A Commercial Activated Carbon (CAC) was used for comparison purposes. The chars were non-porous materials mainly composed by ashes (68.3-92.6% w/w). The influences of adsorbent loading (solid/liquid ratio - S/L) and in...
Activated carbons from the co-pyrolysis of rice wastes for Cr(III) removal
Dias, Diogo; Bernardo, Maria; Lapa, Nuno; Pinto, Filomena; Matos, Inês; Fonseca, Isabel MariaABSTRACT: Rice husk and polyethylene were mixed (50 % w/w each) and submitted to a pyrolysis assay. Four physical activations with CO2 were performed on the resulting co-pyrolysis char (PC). The activation at 800 °C, for 4h, generated the activated carbon (PAC3) with the best textural properties. PC, PAC3 and a commercial activated carbon (CAC) were characterized and submitted to Cr(III) removal assays. PC had ...
Cattle fat valorisation through biofuel production by hydrogenation in supercri...
Morais, Ana Rita C.; Lopes, André; Costa, Paula; Fonseca, Isabel Maria; Nogueira, Isabel N.; Oliveira, Ana Cristina; Lukasik, Rafal M.The use of residues or wastes in biofuel production is a potential solution to the questioned increase of the food market price. The hydrogenation (more specifically hydrodeoxygenation) of residues or wastes rich in free fatty acids seems to be an interesting option for the valorisation of this type of feedstock. The major obstacle of this process is the high temperature and high H2 pressure process requirement...
Sorption of lead (Pb2+) from aqueous solutions using chars obtained in the pyro...
Bernardo, Maria; Mendes, S.; Lapa, Nuno; Gonçalves, Maria Margarida; Mendes, Benilde; Pinto, Filomena; Fonseca, Isabel MariaCarbonaceous solid products resulting from thermochemical processes (pyrolysis, gasification), commonly known as chars, are emerging as low-cost sorbents of metallic contaminants, being their effectiveness already demonstrated in several studies (Inyang et al., 2012; Fuente-Cuesta et al., 2012; Ko³odyñska et al., 2012; Quek and Balasubramanian, 2009; Devecia and Kar, 2013). Given the fact that the commercial vi...