788 research outputs found
Energetic and biochemical valorization of cork boiling wastewater by anaerobic digestion
In addition to energy benefits, anaerobic digestion offers other interesting advantages. The cork industry is of great environmental, economic and social significance in the western Mediterranean region, with Portugal being the world-leading producer and exporter. Cork boiling wastewater (CBW) is a toxic and recalcitrant
organic effluent produced by this sector, which constitutes a serious environmental hazard. However, there is no documented research on anaerobic treatment/valorization
performed with this effluent. The work presented here was developed with the aim to use the anaerobic digestion process to convert the CBW polluting organic load into
an energy carrier gas and valuable molecules for industry
Cork boiling wastewater anaerobic digestion process leads to biogas and valuable enzymes production
Cork is the outer bark of the cork-tree (Quercus suber L.) and it is a very important industrial sector in western Mediterranean region, being Portugal the
world-leading producer and exporter (1). The anaerobic digestion has never been applied to the treatment and valorization of the industrial cork effluents (cork boiling wastewater, CBW). The goal of the present work is evaluate the role of this biological process in providing valuable biomolecules, i.e. enzymes, during the conversion of CBW. Anaerobic experiments were conducted under mesophilic conditions of temperature and the obtained results suggest that CBW is an interesting substrate to be treated and valorised through the anaerobic digestion. Besides the energy recovery through biogas production by anaerobic digestion of CBW, the increase in the reactor effluent of valuable biomolecules is an aspect of great industrial interest. The identification and characterization of such products of high added value creates a supplementary prospect of effluent valorisation, contributing to the cork sector profits. During the CBW anaerobic digestion process several important alterations on the enzymatic capacity of the digested flow were observed. For instance, the laccase activity contained in the CBW was implemented by anaerobiosis and the xilanase was formed during the process. Laccases exhibit low substrate specificity and can be used in different industrial sectors (i.e. paper manufacturing, wine stabilization and
wastewater treatment) (2). Xylanases are enzymes involved in the hydrolyse carbohydrates and are used in the pulp, paper and food industries (3). The production of enzymes with commercial interest offers an additional opportunity for the biotechnological valorisation of the CBW, contributing to make the process more interesting and cheaper
Raça Sorraia: primeiro nascimento mundial por transferência embrionária
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Removal efficiency of Cu2+, Cd2+ and Pb2+ by waste brewery biomass : pH and cation association effects
In this work two distinct (flocculent and non-flocculent) yeast wastes from Portuguese breweries were used for the
selective removal of Cu2+, Cd2+ and Pb2+ from aqueous solutions. One of the goals was to establish both the pH profiles
for the removal of each metal ion (1.0 mM) and the effect on the biomass biosorption capacity of pH adjustment during
the process. The effect of the presence of multiple metal ions, in the 0.1-1.0 mM range, on metal removal efficiency
was also studied. The results showed that, in the absence of pH adjustment, the optimum initial pH for the removal of
three cations was in the 4.5-5.5 range for both types of biomass. However, a gradual pH increase was observed during
the removal process, up to a final equilibrium value of 7.0-8.0. Regarding the biomass efficiency for metal removal in
multi-cation systems, it was verified that only Cu2+ was significantly affected by the presence of the other metals in
solution and only when the non-flocculent yeast biomass was used as biosorbent. Cd2+ was only slightly affected by the
presence of both Cu2+ and Pb2+, and Pb2+ removal was not affected by the presence of any or both of the interferent
metals for the two biosorbents used in this work. The highest and lowest metal removal yields were obtained for Pb2+
and Cu2+, respectively.Fundação para a Ciência e a Tecnologia (FCT) - Praxis XXI 2/2.1/Bio/3 7/94
NMR conformational study of diamagnetic complexes of some triazatriacetate macrocycles
The conformational properties of the diamagnetic complexes formed by five triazatriacetic macrocyclic ligands with monovalent (alkaline) and divalent (alkaline-earth, Zn2+ and Cd2+) cations have been studied by proton nuclear magnetic resonance spectroscopy (1H NMR) in aqueous solution as a function of pH and temperature. These structurally related triazatriacetic ligands, 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA), 1,4,7-triazacyclodecane-N,N',N''-triacetic acid (DETA), 1,4,8-triazacycloundecane-N,N',N''-triacetic acid (UNTA), 1,5,9-triazacyclododecane-N,N',N''-triacetic acid (DOTRA), and 9,10-benzylidene-1,4,7-triazacyclotridecane-N,N',N''-triacetic acid, (BUNTA) have triazamacrocyclic rings with different sizes and flexibilities, bearing three pendant acetate arms. In the case of the alkaline-earth, Zn2+ and Cd2+ cations, only one complex form (1:1) has been detected for all the ligands studied. In most cases the metal ion is coordinated to all the ligand ring nitrogens and to all or some of the carboxylate groups of the pendant arms, except when a poor fit of the cations into the macrocyclic hole occurs, such as for the Ba2+ complexes of DETA, UNTA and DOTRA and the Ca2+ and Sr2+ complexes of BUNTA. The resonance patterns of the ring proton resonances, determined by the long lifetime of the metal-nitrogen bonds, indicate that the six-membered rings formed upon chelation are conformationally rigid and the five-membered rings are conformationally flexible. The multiplicity of the acetate proton resonances shows that the metal-oxygen bonds are long-lived or short lived depending whether the acetates are bound to nitrogens involved in two ring bridges of equal or unequal sizes.http://www.sciencedirect.com/science/article/B6TG5-3T829PD-1D/1/7651a74d4d83a8b051a5d0b9286244e
Treatment of wastewaters contaminated with heavy metals using aerobic granules in a sequencing batch reactor
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Straightforward method for the preparation of lysine-based double-chained anionic surfactants
Double-chained surfactants with potential biocompatibility have been prepared in high yields by lysine acylation with four natural saturated fatty acids (C(6) to C(12)) and with cis-undec-5-enoic acid. The surfactants were found to assemble into nanotubules in aqueous medium and, when mixed with a commercial cationic surfactant, to spontaneously form liposomes
Bioactive compounds through anaerobic digestion of heterotrophic microalgae residues
Several important biomolecules are available into anaerobically digested effluents that were obtained from the biodiesel production process using heterotrophically grown microalga Chlorella protothecoides. Defatted microalgae residues and crude glycerol may undergo anaerobic digestion, separately and in admixture, providing methane/hydrogen and a digestate exploitable for agriculture applications. Furthermore, industrial interesting bioactive compounds such as polyphenols provided with antioxidant activity can be obtained. Anaerobic process offers a promising chance and can be advantageously combined with algae lipid-extraction techniques in order to make it more sustainable
In vitro polarized Raman analysis for the evaluation of the efficacy of CPP-ACP remineralizing mousse in tooth hypomineralization
UID/FIS/ 04559/2020The purpose of this in vitro study is to evaluate the efficacy of a commercially available tooth mousse in the remineralization of human enamel in cases of Molar-incisor-hypomineralization (MIH). Treatment protocol with GC Tooth Mousse containing Casein phosphopeptide amorphous calcium phosphate (CPP-ACP) was applied to 12 teeth (4 healthy, 4 hypomineralized with white opacities and 4 hypomineralized with yellow opacities) and the samples were evaluated with polarized Raman microscopy. The depolarization ratio of the symmetric stretching band of phosphate band was compared in each sample before and after treatment with the tooth mousse. The mean depolarization ratio values decreased in all three groups, after the treatment protocol, with significant differences (p < 0.05) for the two hypomineralized teeth’ groups. These results allowed us to conclude that there was an improvement in mineral density and organization of the hypomineralized enamel after treatment with CPP-ACP tooth mousse.publishersversionpublishe
Evaluation of the Efficacy of CPP-ACP Remineralizing Mousse in MIH White and Yellow Opacities—In Vitro Vickers Microhardness Analysis
Funding Information: This research was funded by Fundação para a Ciência e Tecnologia (FCT) (Portugal) by the research center grant UID/FIS/04559/2021 to LIBPhys from the FCT/MCTES/PIDDAC, Portugal. This research was also funded by Cuf, SA by Inês Cardoso-Martins PhD scholarship. Publisher Copyright: © 2022 by the authors.Remineralization of tooth enamel can be partially achieved by the application of a casein phosphopeptides and amorphous phosphate (CPP-ACP) complex. However, evidence to support its effectiveness in Molar-incisor-hypomineralization (MIH)-affected teeth is scarce. The study’s aim is to evaluate the efficacy of CPP-ACP mousse in remineralizing MIH-affected enamel using a Vickers microhardness test. Two groups of enamel opacities of hypomineralized permanent teeth, white (group A) and yellow (group B) lesions (n = 14), went through a 28-day treatment protocol with GC Tooth Mousse. Before and after treatment, microhardness was measured in three different areas of each tooth (hypomineralized, transition, and outside the hypomineralized area). Data were analyzed using parametric and non-parametric tests with a significance of p < 0.05. The mean microhardness values increased in the hypomineralized and transition areas in both groups after the treatment protocol (in group A, 105.38 ± 11.70 to 158.26 ± 37.34; 123.04 ± 22.84 to 156.33 ± 35.70; in group B, 108.63 ± 14.66 to 143.06 ± 22.81; 132.55 ± 20.66 to 146.00 ± 12.88) and the differences pre/post-treatment were statistically significant within each group (p < 0.001 for both groups). Between groups, there was a statistically significant difference in the same areas (hypomineralized: p = 0.003; transition: p = 0.008) with a higher improvement in enamel hardness in group A. Topical application of CPP-ACP showed an increase in the physical strength of the hypomineralized and transition areas of MIH-affected enamel, likely due to an increase in mineral content.publishersversionpublishe
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