221 research outputs found

    Wastewater Treatment by Advanced Oxidation Process and Their Worldwide Research Trends

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    Background: Water is a scarce resource and is considered a fundamental pillar of sustainable development. The modern development of society requires more and more drinking water. For this cleaner wastewater, treatments are key factors. Among those that exist, advanced oxidation processes are being researched as one of the sustainable solutions. The main objective of this manuscript is to show the scientific advances in this field. Methods: In this paper, a systematic analysis of all the existing scientific works was carried out to verify the evolution of this line of research. Results: It was observed that the three main countries researching this field are China, Spain, and the USA. Regarding the scientific collaboration between countries, three clusters were detected—one of Spain, one of China and the USA, and one of Italy and France. The publications are grouped around three types of water: industrial, urban, and drinking. Regarding the research, 15 clusters identified from the keywords analyzed the advanced oxidation process (alone or combined with biological oxidation) with the type of wastewater and the target pollutant, removal of which is intended. Finally, the most important scientific communities or clusters detected in terms of the number of published articles were those related to the elimination of pollutants of biological origin, such as bacteria, and of industrial nature, such as pesticides or pharmaceutical products

    Ozonation, photocatalysis and photocatalytic ozonation of diuron. Intermediates identification

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    Authors thank economic support received from Gobierno de Extremadura and CICYT of Spain through Projects GRU10012 and CTQ2012-35789-C02-01, respectively. Mr. Rafael Rodríguez Solís also thanks Gobierno de Extremadura, Consejería de Empleo, Empresa e Innovación, and FSE Funds for his Ph.D. grant (PD12058).Aqueous 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) has been oxidized by ozonation, photocatalysis and photocatalytic ozonation. Diuron degradation takes place via radical pathway through hydroxyl radicals in those systems involving ozone. Diuron elimination in photocatalytic ozonation is not enhanced if compared to single ozonation; however, TOC removal was significantly improved. Specifically, 80% TOC removal in 2 h was reached in photocatalytic ozonation while single ozonation just led to 25% TOC reduction. Photocatalysis required 9 h to reach 25% TOC reduction. Ten transformation by-products generated during the application of the three technologies were tentatively identified by liquid chromatography–quadrupole time-of-flight mass spectrometry (LC–QTOF–MS/MS). Single ozonation and photocatalytic ozonation led to the formation and complete elimination of all by-products. Low weight carboxylic acids evolution suggests that high TOC removal in photocatalytic ozonation is linked to its capacity to oxidize small oxygenated compounds and release of inorganic chloride and nitrate. Toxicity evolution to Vibrio fischeri in photocatalytic ozonation displayed an increase in inhibition at the initial stages (>90% of inhibition), followed by a decrease of this parameter as the reaction progressed. The final treated sample shows a lower toxicity than the initial one (55% vs 20%).Gobierno de Extremadura GRU10012CICYT of Spain CTQ2012-35789-C02-01Gobierno de Extremadura, Consejería de Empleo, Empresa e InnovaciónFSE Funds PD1205

    Assessment of animal welfare in sport horses in the equestrian discipline of endurance by adapting the AWIN protocol

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    Oral session 1[EN] The World Health Organisation (WHO) considers an animal to be in a satisfactory state of welfare when it is healthy, comfortable and well nourished, can express its innate behaviour and is not in pain, fear or stress

    Copper-Catalyzed Oxidation of Alkenes and Heterocycles

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    A variety of copper species catalyze the allylic oxidation of olefins and the introduction of an ester group at the α-position of a heterocycle. Both transformations are closely related in terms of reaction conditions and radical species involved. This short review highlights the progress made in these two types of oxidations, emphasizing work that has occurred within the last fifteen years

    Macroecological patterns of the phytoplankton production of polyunsaturated aldehydes

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    The polyunsaturated aldehydes (PUAs) are bioactive metabolites commonly released by phytoplankton species. Based primarily on laboratory experiments, PUAs have been implicated in deleterious efects on herbivores and competing phytoplankton species or in the regulation of the rates of bacterial organic matter remineralization; however, the role of the PUAs at an ecosystem level is still under discussion. Using data of PUA production in natural phytoplankton assemblages over a wide range of conditions, we analyzed macroecological patterns aiming for a comprehensive environmental contextualization that will further our understanding of the control and ecologic role played by these compounds. PUA composition changed from the predominance of decadienal in oligotrophy, octadienal in eutrophy, and heptadienal at intermediate conditions. The production of PUAs per unit biomass also showed a strong relationship with the trophic status, sharply increasing towards oligotrophic conditions and with small-sized cells reaching the highest production rates. High ratios of dissolved inorganic nitrogen to dissolved inorganic phosphorus also promoted PUA production, albeit to a considerably lesser extent. Although the allelopathic use of PUAs to outcompete other phytoplankton or reduce herbivory may be key in some environments and interactions, the macroecological patterns found here, showing higher production towards the poorest waters and among the small species typically populating these environments, support and link at the large scale the hypotheses of the nutrient-derived stress as driver for the production of PUAs together with the use of these compounds as boosters for the nutrient remineralization

    Visibility graphs of ground-level ozone time series: A multifractal analysis

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    A recent method based on the concurrence of complex networks and multifractal analyses is applied for the first time to explore ground-level ozone behavior. Ozone time series are converted into complex networks for their posterior analysis. The searched purpose is to check the suitability of this transformation and to see whether some features of these complex networks could constitute a preliminary analysis before the more thorough multifractal formalism. Results show effectively that the exposed transformation stores the original information about the ozone dynamics and gives meaningful knowledge about the time series. Based on these results, the multifractal analysis of the complex networks is performed. Looking at the physical meaning of the multifractal properties (such as fractal dimensions and singularity spectrum), a relationship between those and the degree distribution of the complex networks is found. In addition to all the promising results, this novel connection between time series and complex networks can deal with both stationary and non-stationary time series, overcoming one of the main limitations of multifractal analysis. Therefore, this technique can be regarded as an alternative to give supplementary information within the study of complex signals

    Relationships between Reference Evapotranspiration and Meteorological Variables in the Middle Zone of the Guadalquivir River Valley Explained by Multifractal Detrended Cross-Correlation Analysis

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    The multifractal relationship between reference evapotranspiration (ET0), computed by the Penmann-Monteith equation (PM), relative humidity (RH) and mean surface temperature (Tmean) was studied in the middle zone of the Guadalquivir River Valley (south Spain) in a previous study. This work extends that study to the average wind speed (U2) and solar radiation (SR), focusing on more recent years. All agro-meteorological variables were analyzed by multifractal detrended cross-correlation analysis (MFCCA) and multifractal detrended fluctuation analysis (MFDFA). The outcomes revealed persistent long-term autocorrelations, with Tmean and RH having the highest persistence (H>0.75). More precise results of multifractal properties than in the previous study were obtained for ET0, Tmean, and RH due to the elimination of trends in the signals. Only medium and large fluctuations in ET0 showed multifractal cross-correlations with its controlling factors, except for U2. Moreover, joint scaling exponents differed from individual exponents. These phenomena contrast with what has been observed in previous cross-correlation studies, revealing that some differences exist in the dynamics of multifractality among the analyzed variables. On the other hand, the Tmean–ET0 relation showed that extreme events in ET0 are mainly ruled by high temperature fluctuations, which match conclusions drawn in the previous study

    Multifractal analysis application to the study of fat and its infiltration in Iberian ham: Influence of racial and feeding factors and type of slicing

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    This paper explores the multifractal features of different commercial designations of Iberian ham (acorn 100% Iberian ham, acorn Iberian ham, feed/pasture Iberian ham and feed Iberian ham). This study has been done by taking as input the fatty infiltration patterns obtained from digital image analysis of ham cuts comparing mechanic and manual slicing. The yielded results show the multifractal nature of fatty connective tissue in Iberian ham, only when knife cutting is applied, confirming the differences between the designations according to their genetics and feeding. Thus, the multifractal parameters presented in this work could be considered as additional information for checking Iberian ham quality by using non-destructive methods based on the combination of image analysis and predictive techniques. Meat industry can take advantage of these methods to evaluate meat products, especially when fat-connective tissue with complex pattern distribution is involved

    Comparative characterization of three Tetraselmis chui (Chlorophyta) strains as sources of nutraceuticals

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    Species of the genus Tetraselmis have traditionally been used as a valuable nutritional source in aquaculture for their high fatty acid content (5-10% dry weight). Their use in nutraceutical production for humans is growing worldwide. Among them, Tetraselmis chui is generally reported in the literature as rich in polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We evaluated the potential of three T. chui strains for the production of these nutraceuticals: the model strain CCAP 8/6, which is broadly used in the aquaculture industry due to its high PUFA content, and two strains (TCBG-1 and TCBG-2) isolated from Guanabara Bay (Rio de 28 Janeiro, Brazil). The two Brazilian strains grew faster than CCAP 8/6 with higher percentage of PUFAs (up to 70% of total FA at the exponential growth phase). They also produced unique fatty acids in significant quantities: TCBG-1 produced arachidonic acid (ARA) and EPA during the exponential phase (> 20% of total FA), while TCBG-2 produced these PUFAs in addition to DHA (>18% of total FA) at the late exponential phase. A two-stage growth system using co-cultures of the two Brazilian strains is proposed as an optimal model for PUFA production, based on their simultaneous scaling cultivation in photobioreactors. Furthermore, both strains are suitable candidates for upscaling in open systems in tropical regions since they are adapted to the environmental conditions in Guanabara Bay, where they form massive blooms by outcompeting other microalga
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