11 research outputs found

    Application of coagulation by sweep for removal of metals in natural water used in dairy cattle

    Get PDF
    Use contaminated water to wash the teats of animals and tools, among others, is due to the presence of potential pathogens and pesticide residues, antibiotics and metalsin raw milk. Washing with water of excellent quality, premilkingis a key to reduce the contamination of milk and prevent these compounds are adsorbed on the skin of theudder and then migrate to milk gun. Aluminum sulfate, ferricchloride and chitosan for the removal of turbidity, colorand TOC in natural waters used in the daily activities of a dairy herd, plus the removal of metals such as copper, cobalt and zinc was assessed found was used frequently in natural waters in some regions of Colombia, in this case using the sweep coagulation to improve the removal efficiency. Ferric chloride was the most effective coagulant for conventional removal of turbidity, color and TOC removal percentages greater than 70% and a coagulant dose of 60 mg/L, while for the optimum metal removal doses were 235 mg/L and 500 mg/L aluminum sulfate, and 300 mg/Land 510 mg/L of ferric chloride, achieving removal percentages above 80 % for most metals. Chitosan did not showlarge removal efficiencies compared to other coagulants

    Sensitive spectrophotometric determination of hydrogen peroxide in aqueous samples from advanced oxidation processes: Evaluation of possible interferences

    Get PDF
    Hydrogen peroxide (H2O2) determination in real watersamples was carried out in a simple and sensitiveway. The resulting optimal operating conditions froma 23 full factorial experimental design were 450 nm, 50mm and 6x10-3 M for the absorption wavelength, thequartz cell path length and the final concentration ofthe ammonium monovanadate solution, respectively;allowing the quantification of H2O2 up to 2.94x10-3mM. The proposed analytical method was validatedand the effect of the background matrix was investigated,obtaining a selective method. Additionally, thedeveloped analytical method was applied for studyingthe evolution of H2O2 in the decontamination of watercontaining 6.73x10-5 mM of anthracene and 1.19x10-5mM of benzo[a]pyrene using the UV/H2O2 system. Itwas found that the optimal H2O2 level enabling about45% of mineralisation and a removal of the targetpolycyclic aromatic hydrocarbons higher than 99%was 2.94x10-1 mM, remaining approximately 1.47x10-1 mM of H2O2 after 90 min of treatment

    Endocrine disruptive action of diclofenac and caffeine on Astyanax altiparanae males (Teleostei: Characiformes: Characidae)

    Get PDF
    Diclofenac (DCF) and caffeine (CAF) are persistent pharmaceuticals that occur in mixtures in the aquatic ecosystems causing effects in the reproductive physiology of aquatic organisms. This study evaluated the physiological reproductive responses of Astyanax altiparanae males exposed to nominal concentrations of DCF (3.08 mg L− 1) and CAF (9.59 mg L− 1) separately and combined, for 96 h. The steroids profile, estrogenic biomarker vitellogenin (vtgA), testes and liver morphology, and also mortality of males were assessed. DCF and CAF degradation was 5% of the initial concentration for 24 h. The LC50 of the DCF and CAF were 30.8 mg L− 1 and 95.9 mg L− 1, respectively. Males exposed to DCF and CAF exhibited a reduction of 17β-Estradiol (E2) concentration compared to control (CTL). Similarly, testosterone (T) was also reduced in the DCF treatment, but this response was not observed in 11-Ketotestosterone (11-KT). Males exposed to DCF + CAF combined did not exhibit differences in T, E2 and 11-KT steroids. The vtgA gene expression and the sperm concentration did not change among the treatments. Moreover, acute exposure revealed a hypertrophy of hepatocytes cells in the DCF and DCF + CAF treatments. In conclusion, DCF and CAF, isolated, exhibit an endocrine disruptive activity in A. altiparanae male, an opposite response observed with the mixture of both compounds that abolishes the endocrine disruptive effects. DCF seems to be more toxic for this species, altering also hepatocytes morphology.Fil: Godoi, Filipe G.A.. Universidade de Sao Paulo; BrasilFil: Muñoz Peñuela, Marcela. Universidade de Sao Paulo; BrasilFil: Olio Gomes, Aline D.. Universidade de Sao Paulo; BrasilFil: Tolussi, Carlos E.. Universidade Anhembi-Morumbi; BrasilFil: Brambila Souza, Gabriela. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Branco, Giovana S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Lo Nostro, Fabiana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Moreira, Renata. Universidade de Sao Paulo; Brasi

    Evolutionary Heritage Influences Amazon Tree Ecology

    Get PDF
    Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change

    Mapping density, diversity and species-richness of the Amazon tree flora

    Get PDF
    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Consistent patterns of common species across tropical tree communities

    Get PDF
    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Comparative Degradation of Alachlor Using Photocatalysis and Photo-Fenton

    No full text
    A comparative study about the degradation of alachlor in aqueous solutions under different photocatalytic systems, including TiO2, TiO2/H2O2, and TiO2/Na2S2O8 heterogeneous photocatalysis, Fe2+/H2O2, Fe3+/H2O2, and UV radiation, was carried out. In this way, times for alachlor total removal and mineralization followed the order photo-Fenton < photocatalysis with persulfate < photo-Fenton-like < photocatalysis with hydrogen peroxide < photocatalysis with TiO2. Ferric chloride was used as ferric ion source under Fenton-like reactions. Oxidation with Fe2+/H2O2 was faster than treatment with Fe3+/H2O2, but under UV irradiation, degradation rates were similar, indicating that FeCl3 could be a good source of ferric ions for alachlor degradation. Reduction of the sample toxicity was much faster in the photo-Fenton process than in TiO2 process (50% mortality reduction in 180 min compared to around 400 min—Daphnia Pullex assays). In addition, evaluation of the nitrogen and chloride contained in the treated samples confirmed a 100% conversion of the N and Cl content in the pollutant molecule. Finally, some of the degradation by-products for pollutant removal using TiO2 photocatalysis were identified. © 2018, Springer Nature Switzerland AG

    Harmonization of the quantitative determination of volatile fatty acids profile in aqueous matrix samples by direct injection using gas chromatography and high-performance liquid chromatography techniques: Multi-laboratory validation study

    Full text link
    The performance parameters of volatile fatty acids (VFAs) measurements were assessed for the first time by a multi-laboratory validation study among 13 laboratories. Two chromatographic techniques (GC and HPLC) and two quantification methods such as external and internal standard (ESTD/ISTD) were combined in three different methodologies GC/ESTD, HPLC/ESTD and GC/ISTD. Linearity evaluation of the calibration functions in a wide concentration range (10-1000mg/L) was carried out using different statistical parameters for the goodness of fit. Both chromatographic techniques were considered similarly accurate. The use of GC/ISTD, despite showing similar analytical performance to the other methodologies, can be considered useful for the harmonization of VFAs analytical methodology taking into account the normalization of slope values used for the calculation of VFAs concentrations. Acceptance criteria for VFAs performance parameters of the multi-laboratory validation study should be established as follows: (1) instrument precision (RSDINST≤1.5%); (2) linearity (R2≥0.998; RSDSENSITIVITY≤4%; REMAX≤8%; REAVER≤ 3%); (3) precision (RSD≤1.5%); (4) trueness (recovery of 97-103%); (5) LOD (≤3mg/L); and (6) LOQ (10mg/L

    Persistent effects of pre-Columbian plant domestication on Amazonian forest composition

    No full text
    corecore