38 documents found, page 1 of 4
Valorization of chicken feathers using aqueous solutions of ionic liquids
Polesca, Cariny; Passos, Helena; Neves, Bruno M.; Coutinho, João A. P.; Freire, Mara G.The poultry-processing industry generates large quantities of waste rich in keratin, a fibrous protein representing around 90 wt % of chicken feathers, which is currently disposed of in landfilling or incinerated. Keratin is commonly recognized as a renewable biopolymer resource used for biomaterials preparation (e.g., films and hydrogels) with interest for biomedical applications. Even though research on kerat...
The role of biomass elemental composition and ion-exchange in metal sorption by...
Carreira, Ana R. F.; Veloso, Telma; Macário, Inês P. E.; Pereira, Joana L.; Ventura, Sónia P. M.; Passos, Helena; Coutinho, João A. P.The use of macroalgae, microalgae and cyanobacteria for metal sorption has been widely reported. Still, there are no studies allowing a direct comparison of the performance of these biomasses, especially while evaluating metal competition. The simultaneous sorption of Co2+, Cu2+, Ni2+ and Zn2+ present in a multi-elemental solution by six macroalgae, two microalgae and three cyanobacteria was evaluated. Brown ma...
Simple gold recovery from e-waste leachate by selective precipitation using a q...
Nogueira, André F.M.; Carreira, Ana R.F.; Vargas, Sílvia J.R.; Passos, Helena; Schaeffer, Nicolas; Coutinho, João A.P.Precipitation processes, if selective, present a simple and economical alternative for the recovery of critical metals from primary and secondary ores including electronic wastes. In this work, the recovery of gold by precipitation from both mono-elemental solutions and real CPU leach solution was demonstrated using hydrophilic quaternary ammonium salts. The gold precipitation yield is shown to be dependent on ...
Cyanobacteria as candidates to support mars colonization: growth and biofertili...
Macário, Inês P. E.; Veloso, Telma; Frankenbach, Silja; Serôdio, João; Passos, Helena; Sousa, Clara; Gonçalves, Fernando J. M.; Ventura, Sónia P. M.Cyanobacteria are indicated as organisms that can possibly support Mars colonization, contributing to the production of oxygen and other commodities therein. In this general context, the aim of this work was to evaluate the ability of three species of cyanobacteria (Anabaena cylindrica, Nostoc muscorum, and Arthrospira platensis) and a green microalga (Chlorella vulgaris) to grow using only the resources existi...
Sustainable development of biomaterials using ionic liquids
Polesca, Cariny; Passos, Helena; Coutinho, João A. P.; Freire, Mara G.This review summarizes and critically addresses the advances achieved on the processing of biomaterials, namely films, scaffolds, and nanoparticles, using ionic liquids as alternative solvents. Biomaterials composed of proteins, polysaccharides, and their blends are here considered. Despite their relevance, the low solubility of these compounds in most solvents represents a major limitation on biomaterials proc...
Cyanobacteria as Candidates to Support Mars Colonization: Growth and Biofertili...
Macário, Inês P. E.; Veloso, Telma; Frankenbach, Silja; Serôdio, João; Passos, Helena; Sousa, Clara; Gonçalves, Fernando J. M.; Ventura, Sónia P. M.Cyanobacteria are indicated as organisms that can possibly support Mars colonization, contributing to the production of oxygen and other commodities therein. In this general context, the aim of this work was to evaluate the ability of three species of cyanobacteria (Anabaena cylindrica, Nostoc muscorum, and Arthrospira platensis) and a green microalga (Chlorella vulgaris) to grow using only the resources existi...
Crustacean waste biorefinery as a sustainable cost-effective business model
Vicente, Filipa A.; Ventura, Sónia P. M.; Passos, Helena; Dias, Ana C. R. V.; Torres-Acosta, Mario A.; Novak, Uroš; Likozar, BlažMarine-derived food wastes mainly include seafood, fish and feed production resources. From the crustaceans traded annually, 6 to 8 million tonnes of valuable shrimp, lobster and/or crab shells waste are produced worldwide. In this systemic work, the researchers with complementary technical expertise, covering the fields of chemical engineering design, chemistry, materials, predictive environmental sciences and...
Factors driving metal partition in ionic liquid-based acidic aqueous biphasic s...
Carreira, Ana R.F.; Passos, Helena; Schaeffer, Nicolas; Svecova, Lenka; Papaiconomou, Nicolas; Billard, Isabelle; Coutinho, João A.P.The factors influencing metal partition in acidic aqueous biphasic systems (AcABS) containing phosphonium-based ILs are still poorly explored. To assess their influence the effect of the IL counter anion, acid and its concentration, and temperature, were systematically evaluated on the extraction of four transition metals (Cu(II), Co(II), Ni(II), and Mn(II)) and the lanthanide Ce(IV). The AcABS based on HCl sho...
Amino-acid-based chiral ionic liquids characterization and application in aqueo...
Carreira, Ana R. F.; Rocha, Samuel N.; Silva, Francisca A. e; Sintra, Tânia E.; Passos, Helena; Ventura, Sónia P. M.; Coutinho, João A. P.By using amino acids as anions, ten chiral ionic liquids (CILs) composed of tetrabutylammonium or cholinium as cations were synthesized by neutralization reactions and further characterized by assessing their optical rotation, thermophysical properties (melting and decomposition temperatures, density, viscosity and refractive index) and ecotoxicity against the marine bacterium Aliivibrio fischeri. The CILs are ...
Selective sequential recovery of zinc and copper from acid mine drainage
Passos, Helena; Cruz, Brayan; Schaeffer, Nicolas; Patinha, Carla; Silva, Eduardo Ferreira da; Coutinho, João A. P.The observed imbalance between the unsustainable consumption of available natural metal resources and finite deposits makes the recovery and recycling of metals from metal-containing wastes an imperative. Here, ionic-liquid-based aqueous biphasic systems (IL-based ABSs) are proposed as an efficient alternative for selective metal recovery from real copper acid mine drainage (AMD) effluents. ABSs composed of dif...