25 research outputs found

    Long-Term Effects of Calcium-Based Liming Materials on Soil Fertility Sustainability and Rye Production as Soil Quality Indicators on a Typic Palexerult

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    [EN] Liming is a common practice used to improve acidic soil properties, as is essential for agricultural quality. A long-term field experiment with one lime rate (6000 kg/ha of carbonate calcium equivalent) and three calcium-based liming amendments (gypsum, limestone and sugar foam) was maintained on a Typic Palexerult for 10 years in order to determine changes in soil acidity and to assess the effects on crop (rye) yields. The soil acidity conditions decreased with all the amendments tested, but the sugar foam and limestone was more effective than gypsum over a long-term period. No significant changes in organic soil matter levels between the treatments tested were found. Interestingly, an increase in the leaching of organic soil matter was observed in limed soils. Lime application significantly increased the total rye biomass compared to the control soils during the whole experiment (2002–2011). Yield trends observed in spike and stem biomass were similar to those reported for total rye biomass. In this respect, at the end of the research, gypsum, limestone and sugar foam increased in relation to the total production of rye biomass by 16%, 32% and 38%, respectively, as compared to the control soils. Additionally, a significant and prolonged difference in calcium concentrations in rye stems between unlimed and limed subplots was observed. However, in spite of the results presented here, further investigations are needed to gain a better understanding of the long-term effects of liming on the chemical properties of soil.S

    Effects of overliming on the nutritional status of grapevines with special reference to micronutrient content

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    [EN] Aluminium plays a central role in soil acidity, which is one of the main constraints on grape production in humid, northern temperate viticultural regions. To decrease the acidity of vineyard soil, it is usually amended with alkaline materials that provide conjugate bases to weak acids (liming). However, one practical consideration is the danger of overliming, which has potential implications in terms of yield reduction and decreased bioavailability of several mineral nutrients. The main aim of this study was to evaluate the effects of overliming using dolomitic lime on grapevines growing on acid soil. The effects on the topsoil fertility parameters (0–30 cm), petiole and berry nutrient levels, berry weight and must quality properties were studied in a vineyard planted with Vitis vinifera L. cv. Mencía for three years (2014–2016). Data analysis performed using a mixed model that took into account both random effects (year of sampling) and fixed effects (liming treatments) showed that overliming decreased the manganese content in both leaf and berry tissues. Until now, nothing was known about the effects of overliming on both vine nutritional status and harvest quality properties, thus this study fills an important knowledge gap.SIThe authors are most grateful to Losada Vinos de Finca, S.A., for assisting with this research project

    Parametrization of a Modified Friedman Kinetic Method to Assess Vine Wood Pyrolysis Using Thermogravimetric Analysis

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    [EN] Common kinetic parameters were obtained for leached and non-leached samples of vine wood biomass. Both samples were considered to have different proportions of cellulose, hemicellulose, and lignin compositions as a result of the leaching process. The two samples were analyzed in terms of pyrolysis kinetic parameters using non-isothermal thermogravimetric analysis. Furthermore, the classic Friedman isoconversional method, a deconvolution procedure using the Fraser–Suzuki function, and a modified Friedman method from a previous study on the delay in conversion degree were satisfactorily applied. The observed difference when the deconvolution technique was applied suggests that the classic Friedman method is not adequate for studying the pyrolysis of individual vine wood biomass components. However, this issue was solved by studying the delay in conversion degree of both biomasses and calculating the kinetic parameters using the resulting information. This procedure was found to be useful for studying and comparing the kinetics of heterogeneous biomasses and has a sound scientific explanation, making this research a basis for future similar studies.S

    Evaluation of Joint Management of Pine Wood Waste and Residual Microalgae for Agricultural Application

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    [EN] This work addresses the joint management of residual microalgae and pine wood waste through pyrolysis to obtain a solid product for its use as soil amendment and two other by-products (liquid and gaseous) that can be used for energy purposes. Two management routes have been followed. The first route is through the co-pyrolysis of mixtures of both residual materials in several proportions and the later use of their solid fraction for soil amendment. The second route is the pyrolysis of pine wood waste and its direct combination with dried residual microalgae, also using it as soil amendment. The solid fraction assessment shows that from seven solid products (biochar) three stand out for their positive applicability in agriculture as soil amendment. In addition, they also present the benefit of serving as carbon sink, giving a negative balance of CO2 emissions. However, caution is suggested due to biochar applicability being subject to soil characteristics. To ensure the sustainability of the overall process, the energy available in liquid and gaseous fractions has been assessed for covering the drying needs of the residual microalgae in both cases. These results suggest that the pyrolysis process is a sustainable way to manage specific evaluated residues and their products.S

    Hydrothermal carbonization of olive tree pruning as a sustainableway for improving biomass energy potential: effect of reaction parameters on fuel properties

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    Hydrothermal carbonization (HTC) allows the conversion of organic waste into a solid product called hydrochar with improved fuel properties. Olive tree pruning biomass (OTP), a very abundant residue in Mediterranean countries, was treated by HTC to obtain a solid fuel similar to coal that could be used in co-combustion processes. Three different reaction temperatures (220, 250, and 280 °C) and reaction times (3, 6, and 9 h) were selected. The hydrochars obtained were extensively analyzed to study their behavior as fuel (i.e., ultimate, proximate, fiber and thermogravimetric analysis, Fourier-transform infrared spectroscopy (FTIR), activation energy, and combustion performance). The concentrations of cellulose, hemicellulose, and lignin in the samples depict a clear and consistent trend with the chemical reactions carried out in this treatment. Regarding O/C and H/C ratios and HHV, the hydrochars generated at more severe conditions are similar to lignite coal, reaching values of HHV up to 29.6 MJ kg-1. The higher stability of the solid is reflected by the increase of the activation energy (≈60 kJ mol-1), and ignition temperatures close to 400 °C. With this, HTC is a proper thermal treatment for the management of raw OTP biomass and its further conversion into a solid biofuel.Judith González-Arias would like to thank the Junta de Castilla y León (Consejería de Educación) fellowship, Orden EDU/1100/2017, cofinanced by the European Social Fund.info:eu-repo/semantics/publishedVersio

    Scaling-Up of the Production of Biochar from Olive Tree Pruning for Agricultural Use: Evaluation of Biochar Characteristics and Phytotoxicity

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    [EN] Due to the large acreage of olive trees in the Mediterranean basin, the biochar from olive tree pruning may become an important resource as part of circular economy strategies. However, so far, there is not much knowledge on whether the same characteristics are repeated in biochar once production is up-scaled to an industrial level. Accordingly, this study aimed to scale up the production of olive tree pruning biochar with three reactors (semi-pilot, pilot and industrial) to ascertain the production parameters that determine the characteristics of the obtained biochar and its possible toxicity to use in agriculture or environmental applications. First, the production conditions in the semi-pilot reactor were optimised by testing three temperatures (400, 500 and 600 °C), with the result that 600 °C was the optimal production temperature because of a high carbon content (70.88%), moderate pH (8.1), good carbon sink (R50 > 0.5) and low contents of PAHs (<6 mg/kg) and heavy metals, resulting in a phytostimulanting effect for all the crops studied. Then, the production was upscaled, using 600 °C as pyrolysing temperature. At the industrial scale, accurate temperature control is essential because when temperatures above 650 °C were reached, the biochar showed a pH above 11, resulting in severe phytotoxicity. The longer retention time of the material in the industrial pyrolysers improved the carbon stability and, therefore, the biochar’s role as a carbon sink. Consequently, it was proven that it is possible to produce olive tree pruning biochar adequate for agriculture and environmental applications with large-scale equipment, and the two most important factors needing control are the temperature and retention time.SIThis research was co-funded by the research project “Desarrollo de fertilizantes avanzados a partir de subproductos del olivar y bioestimulantes microbianos” (BIFEROLIVA) [IDI-20191225] co-funded by Cortijo de Guadiana S.A. and CDTI (Spanish Ministry of Science and Innovation)

    El Problem Based Learning plus, PBL+, a examen, una metodología ecléctica y flexible, para competencias prácticas en ingeniería

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    [ES] Problem Based Learning Plus (PBL+) es una metodología docente para alcanzar las competencias prácticas en ingeniería, incluyendo a ingenieros químicos, ambientales y agrónomos, y también a biotecnólogos especializados en procesos de producción. PBL+ se basa en la metodología PBL tradicional, pero combina otras metodologías de enseñanza-aprendizaje: la clase invertida, el uso de rúbricas para la evaluación de la actividad, el aprendizaje colaborativo y en algunos casos, el aprendizaje-servicio. Un aspecto relevante es que los estudiantes son libres de elegir el problema sobre el que van a trabajar. Aún más importante es que el problema a resolver debe ser una situación real a la que se enfrenta la empresa. Son los estudiantes los que entran en contacto con una empresa cuyo campo de actividad corresponda a las competencias de la asignatura y seleccionan, junto con un representante de la empresa, el problema a resolver. De este modo, los estudiantes tienen un papel activo en la definición de las prácticas de la asignatura. Esta forma flexible de construir el currículo del estudiante ha demostrado motivarlos, siendo una excelente estrategia para abordar problemas reales de su especialidad. No obstante, no todos los sectores de la ingeniería están dispuestos a compartir sus problemas con los estudiantes. En este sentido, la industria biotecnológica es muy reticente a hacerlo, mientras que el sector agrario es proclive a ello. En este trabajo, se resumen los resultados de la evaluación a la que se ha sometido el PBL+ durante 4 cursos consecutivos, aplicando 9 indicadores que evalúan 7 resultados de aprendizaje. Además, se resume el tipo de problemas sobre los que han trabajado los estudiantes de ingeniería agronómica durante los 4 cursos, que corresponden a los problemas que más preocupan a las empresas del sector: el 60% de los problemas están relacionados con aspectos fitosanitarios, principalmente plagas o enfermedades emergentes. En segundo lugar, el 30% corresponde a alteraciones en el crecimiento de los cultivos por factores abióticos. El 10% restante consiste en adaptar los procesos productivos a los cambios legislativo

    Clinical validation of risk scoring systems to predict risk of delayed bleeding after EMR of large colorectal lesions

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    [Background and Aims]: The Endoscopic Resection Group of the Spanish Society of Endoscopy (GSEED-RE) model and the Australian Colonic Endoscopic Resection (ACER) model were proposed to predict delayed bleeding (DB) after EMR of large superficial colorectal lesions, but neither has been validated. We validated and updated these models.[Methods]: A multicenter cohort study was performed in patients with nonpedunculated lesions ≥20 mm removed by EMR. We assessed the discrimination and calibration of the GSEED-RE and ACER models. Difficulty performing EMR was subjectively categorized as low, medium, or high. We created a new model, including factors associated with DB in 3 cohort studies.[Results]: DB occurred in 45 of 1034 EMRs (4.5%); it was associated with proximal location (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.31-6.16), antiplatelet agents (OR, 2.51; 95% CI, .99-6.34) or anticoagulants (OR, 4.54; 95% CI, 2.14-9.63), difficulty of EMR (OR, 3.23; 95% CI, 1.41-7.40), and comorbidity (OR, 2.11; 95% CI, .99-4.47). The GSEED-RE and ACER models did not accurately predict DB. Re-estimation and recalibration yielded acceptable results (GSEED-RE area under the curve [AUC], .64 [95% CI, .54-.74]; ACER AUC, .65 [95% CI, .57-.73]). We used lesion size, proximal location, comorbidity, and antiplatelet or anticoagulant therapy to generate a new model, the GSEED-RE2, which achieved higher AUC values (.69-.73; 95% CI, .59-.80) and exhibited lower susceptibility to changes among datasets.[Conclusions]: The updated GSEED-RE and ACER models achieved acceptable prediction levels of DB. The GSEED-RE2 model may achieve better prediction results and could be used to guide the management of patients after validation by other external groups. (Clinical trial registration number: NCT 03050333.)Research support for this study was received from “La Caixa/Caja Navarra” Foundation (ID 100010434;project PR15/11100006)

    Valorization of agricultural olive waste as an activated carbon adsorbent for the remediation of water sources contaminated with pharmaceuticals

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    The present study investigates the performance of activated carbon from olive pomace (ACOP) in the removal of hydrophilic organic pharmaceutical micropollutants such as the antibiotic sulfamethoxazole (SMX) from water. The adsorption behavior of two chemically modified ACOP was investigated considering their interesting textural properties, relevant surface functions and charges. The performances in terms of adsorption capacity were investigated and optimized with respect to the main operating conditions. Comparison of SMX adsorption capacities on ACOP with commercial powdered activated carbon and nanoporous carbonaceous materials prepared from argan shells revealed that ACOP enabled the highest adsorption capacities (39.68 mg g−1). The adsorption behavior was attributed not only to the textural properties, such as the large surface area (1857 m2 g−1) and porosity, but also to the charge and functional groups of the surface

    Parametrization of a Modified Friedman Kinetic Method to Assess Vine Wood Pyrolysis Using Thermogravimetric Analysis

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    Common kinetic parameters were obtained for leached and non-leached samples of vine wood biomass. Both samples were considered to have different proportions of cellulose, hemicellulose, and lignin compositions as a result of the leaching process. The two samples were analyzed in terms of pyrolysis kinetic parameters using non-isothermal thermogravimetric analysis. Furthermore, the classic Friedman isoconversional method, a deconvolution procedure using the Fraser&ndash;Suzuki function, and a modified Friedman method from a previous study on the delay in conversion degree were satisfactorily applied. The observed difference when the deconvolution technique was applied suggests that the classic Friedman method is not adequate for studying the pyrolysis of individual vine wood biomass components. However, this issue was solved by studying the delay in conversion degree of both biomasses and calculating the kinetic parameters using the resulting information. This procedure was found to be useful for studying and comparing the kinetics of heterogeneous biomasses and has a sound scientific explanation, making this research a basis for future similar studies
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