133 documents found, page 1 of 14
Multicomponent adsorption of pentavalent As, Sb and P onto iron-coated cork gra...
Ariana M. A. Pintor; Cátia C. Brandão; Rui A. R. Boaventura; Cidália M. S. BotelhoThe assessment of multicomponent adsorption of pentavalent metalloids is important since they are often found together in groundwaters and mining runoff. For this purpose, adsorption of As(V), Sb(V) and P(V) onto ironcoated cork granulates was studied in binary and ternary systems. Data from equilibrium and kinetic studies revealed that uptake of these contaminants is a multilayer, heterogeneous process well de...
Development and characterization of a novell-asparaginase/MWCNT nanobioconjugate
Raquel O. Cristóvão; Mafalda R. Almeida; Maria A. Barros; João C. F. Nunes; Rui A. R. Boaventura; José M. Loureiro; Joaquim L. Faria; Márcia C. NevesThe enzymel-asparaginase (ASNase) presents effective antineoplastic properties used for acute lymphoblastic leukemia treatment besides their potential use in the food sector to decrease the acrylamide formation. Considering their applications, the improvement of this enzyme's properties by efficient immobilization techniques is in high demand. Carbon nanotubes are promising enzyme immobilization supports, since...
Quality assessment of water intended for human consumption from Kwanza, Dande a...
Juliana M. Paca; Francisca M. Santos; José C.M. Pires; Anabela A. Leitão; Rui A. R. BoaventuraAngola is one of the countries with a high rate of waterborne diseases, due to the scarcity and poor quality of water for human consumption. The watercourses are receptors of many effluents, mainly domestic sewage, due to a precarious or inexistent sanitation system and a small number of wastewater treatment plants. Therefore, this study aims: (i) to evaluate the water quality (physicochemical and microbiologic...
An innovative multistage treatment system for sanitary landfill leachate depura...
Vítor J. P. Vilar; Tânia F. C. V. Silva; Petrick A. Soares; Diego R. Manenti; Amélia Fonseca; Isabel Saraiva; Rui A. R. BoaventuraIn this work, an innovative methodology for the treatment of landfill leachates, after aerobic lagooning, is proposed and adjusted at pilot-scale. This methodology involves an aerobic activated sludge biological pre-oxidation (ASBO), a coagulation/sedimentation step (240 mg Fe3+/L, at pH 4.2) and a photo-oxidation through a photo-Fenton (PF) reaction (60 mg Fe2+, at pH 2.8) combining solar and artificial light....
Photocatalytic reduction of Cr(VI) over TiO2-coated cellulose acetate monolithi...
Belisa A. Marinho; Raquel O. Cristóvão; Ridha Djellabi; José M. Loureiro; Rui A. R. Boaventura; Vítor J. P. VilarThe major drawback of TiO2 based advanced oxidation processes (AOPs) is the use of massive amounts of dispersed nanoparticles that are hard to recover after the water treatment and potentially harmful for humans due to their very small size. The stabilization of the nanoparticles in an adequate inert support is a good strategy to overcome such limitations. In the present work, the photoreduction of Cr(VI) to Cr...
Photo-Fenton oxidation of 3-amino-5-methylisoxazole: a by-product from biologic...
Bianca M. Souza; Belisa A. Marinho; Francisca C. Moreira; Márcia W. C. Dezotti; Rui A. R. Boaventura; Vítor J. P. VilarThe present study aims to assess the removal of 3-amino- 5-methylisoxazole (AMI), a recalcitrant by-product resulting from the biological breakdown of some pharmaceuticals, applying a solar photo-Fenton process assisted by ferrioxalate complexes (SPFF) (Fe3+/H2O2/oxalic acid/UVA-Vis) and classical solar photo-Fenton process (SPF) (Fe2+/ H2O2/UVA-Vis). The oxidation ability of SPFF was evaluated at different iro...
Intensification of heterogeneous TiO2 photocatalysis using an innovative micro-...
Vítor J. P. Vilar; Batuira M. da Costa Filho; Ana L. P. Araújo; Gabriela V. Silva; Rui A. R. Boaventura; Madalena M. Dias; José C. B. LopesThe main goal of this work is to overcome barriers in heterogeneous TiO2 photocatalysis application towards indoor air decontamination by process intensification. The photocatalytic oxidation (PCO) of gas-phase n-decane was studied using a micro-meso-structured-photoreactor irradiated by simulated solar light, consisting of chambers and channels mechanically engraved in an acrylic slab. The network of chambers ...
Arsenic removal from water using iron-coated seaweeds
Bárbara R. C. Vieira; Ariana M. A. Pintor; Rui A. R. Boaventura; Cidália M. S. Botelho; Sílvia C. R. SantosArsenic is a semi-metal element that can enter in water bodies and drinking water supplies from natural deposits and from mining, industrial and agricultural practices. The aim of the present work was to propose an alternative process for removing As from water, based on adsorption on a brown seaweed (Sargassum muticum), after a simple and inexpensive treatment: coating with iron-oxy (hydroxides). Adsorption eq...
Ferrioxalate complexes as strategy to drive a photo-FENTON reaction at mild pH ...
Vítor J. P. Vilar; André A. Nogueira; Bianca M. Souza; Márcia W. C. Dezotti; Rui A. R. BoaventuraThe present study is about the use of ferrioxalate photoactive complexes as a strategy to drive a photo Fenton reaction at mild pH conditions, applied to the oxidation of antibiotic levofloxacin (LEV) in pure water and spiked in urban wastewater after secondary treatment. The oxidation ability of the solar photo Fenton mediated by ferrioxalate complexes (SPFF) was evaluated at different pH values (3.0 to 6.0) f...
Combination of chemical coagulation, photo-Fenton oxidation and biodegradation ...
Carmen S. D. Rodrigues; Ana R. Neto; Rose M. Duda; Roberto A. de Oliveira; Rui A. R. Boaventura; Luís M. Madeirahe post-treatment of biodigested sugarcane vinasse was envisaged in the present study following three different approaches: i) coagulation/flocculation Approach 1; ii) combination of coagulation/flocculation with photo-Fenton reaction Approach 2; iii) coagulation/flocculation followed by biological degradation and photo-Fenton reaction Approach 3. The coagulation/flocculation per se provided a slight increase i...