In the present study, microplastics (MPs) and metal concentrations were studied in the widely consumed tilapia (Oreochromis niloticus) fishes (n = 15) collected from a metropolitan reservoir of the ...Atoyac River basin, Mexico. Nearly 139 fibers were extracted from the gastrointestinal tracts and assessed using optical microscopy to evaluate their physical characteristics. The colour distribution of the fibers was mainly black (40%), blue (19%), red and white (14%). SEM images represented the surface morphology, while the elemental composition of the fibers was studied using EDX spectra. Polymer characterization using μFTIR aided in confirming the fibers as plastics (polyamide, polyester, and synthetic cellulose) and non-plastics (natural cellulose). Henceforth, ∼33% of the fibers, provisionally thought to be plastics, were natural fibers. The total metal concentrations were higher in the liver (259.24 mg kg−1) than the muscle (122.56 mg kg−1) due to diverse metabolic functions in the hepatic tissues. Human health risk assessment in terms of Hazard Index (HI) presented Pb and Zn values above unity in both adults and children, prompting regulatory measures. Statistical tests between MPs and fish biometry did not present any substantial correlations. The present study also affirmed that the presence of MPs and metals in fishes of a highly contaminated region is not only governed by their bioavailabilities, but also on the physiological characteristics of the individual organism.
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•Microplastic prevalence of 53.67% was found in Freshwater Tilapia from a metropolitan reservoir.•HI values > 1 for Pb and Zn in adults and children prompt remedial actions.•No significant correlations between MPs and fish biometry/metal levels.
This data article presents a simulation model based on quantum mechanics and energy potentials for obtaining simulation data that allows, from the perspective of materials informatics, the prediction ...of the electrodeposition mechanism for forming nanostructured metallic coatings. The development of the research is divided into two parts i) the formulation (Quantum mechanical model and Corrected model for electron prediction; using a modified Schrödinger equation) and ii) the implementation of the theoretical prediction model (Discretization of the model). For the simulation process, the finite element method (FEM) was used considering the equation of electric potential and electroneutrality with and without the inclusion of quantum leap. We also provide the code to perform QM simulations in CUDA®, and COMSOL® software, the simulation parameters, and data for two metallic arrangements of chromium nanoparticles (CrNPs) electrodeposited on commercial steel substrate. (CrNPs-AISI 1020 steel and CrNPs-A618 steel). Data collection shows the direct relationship between applied potential (VDC), current (A), concentration (ppm), and time (s) for the homogeneous formation of the coating during the electrodeposition process, as estimated by the theoretical model developed. Their potential reuse data is done to establish the precision of the theoretical model in predicting the formation and growth of nanostructured surface coatings with metallic nanoparticles to give surface-mechanical properties.
This article presents a computational numerical model for the simulation and analysis of quantum chemistry and Gibbs free energy theory using static (ANNS), dynamic (DANN), and chaotic neural ...networks (CANN). The model calculates the physical-surface mechanics of hardness, adhesion, and strength. They resulted in nanostructured metal coatings with electrodeposited chromium nanoparticles on low-carbon steel. The ANNS, DANN, and CANN simulations showed that model-obtained values for analyzed properties presented an approximation of 99 % concerning theoretical matters taken as base. Likewise, model accuracy was verified by comparison with reference data (datasheet). The proposed model is not limited to the analyzed case and provides consistent results for predicting surface physical-mechanical properties of electrodeposited coating-substrate arrangements, with a minimum error percentage of 1–1.5 % over learning.
•A diesel-contaminated soil from an agricultural area in Mexico was successfully treated•The advanced oxidation process by itself was able to remove up to 84% of the TPH in 48 h.•The sorption process ...with AC by itself was able to remove 58% of the TPH in 60 min•Coupling both processes achieved a up to 98% TPH removal, fulfilling the permissible limit of 1200 mg/Kg.•Soil quality changed as a result of the contamination, and further changes were detected after the treatment.
In central Mexico (state of Puebla), hydrocarbon spillages associated to fuel theft are common. The soil that surrounds these spillages is left useless due to hydrocarbon contamination. Given the increasing number of spillages and the extension of polluted land that they represent, a recovery plan for these soils does not exist. This work proposes the application of advanced oxidation, activated carbon sorption, and the combination of both, as a remediation proposal. Starting with a total petroleum hydrocarbon (TPH) concentration of 55,141 mg/Kg, advanced oxidation degraded a maximum of 84%, sorption removed up to 58%, and the combination of both methods achieved a removal up to 98%. The time invested in the application of both techniques was 50 h, being quite low in comparison with other available methods. The treated soil presented changes in some parameters, including a pH value of 3.8. It is considered that the paired methods of advanced oxidation and sorption represent a good alternative to decontaminate hydrocarbon-contaminated soils.
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Sanitary landfills are the most used way to dispose of the garbage generated in the country. In landfills, it is essential to know the amount of waste that is collected and disposed of, as well as ...its characteristics, such as density, composition, humidity, and calorific value, to design collection, transport, and final disposal systems. This work aims to determine the economic and environmental potential of the methane gas production of generated clean energy in a landfill in Mexico. This work considers standards developed for measuring gases released into the environment. An in situ sampling was carried out in a sanitary landfill in 36 biogas wells using a GA5000 analyzer. The emission of 28,965 tons of methane gas and 83,244 tons of carbon dioxide per day is estimated at the landfill. A negative externality can become positive when the use of solid urban waste produces electrical energy by capturing the greenhouse gases generated in the decomposition of the waste present in the landfill.
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•A quantum chemical model is development for coatings electrodeposition process.•The relationship properties-particle size and deposition technique are studied.•Theoretical results ...demonstrated that coatings growth is function of I, V, Cr.•The developed model has the predictive ability for the electrochemical deposition.
In this paper the deposition and surface growth of chromium nanoparticles (CrNPs) coatings on a commercial steel substrate by electrodeposition at a constant current, is presented; both theoretically through a theoretical-computational model applying a modified Schrödinger equation, energy potentials and electrochemistry and phitosynthesis of Cr Nanoparticles . For the simulation process, the finite element method (FEM) was used considering the equation of electric potential and electroneutrality with and without the inclusion of a quantum leap. The theoretical results are in accordance with the experimental results, considering a three-level multifactorial experiment design with current, voltage and ion concentration as factors and the formation and growth of the coatings as a response function. The results obtained indicate the presence of electro-diffusion at the substrate-coating interface. The developed model has the predictive ability of 97 ± 2 % for the electrochemical deposition of CrNPs on a steel substrate.
Bimetallic Pd/Pt nanoparticles were synthesized by bio-reduction method. The structural characterizations were performed by high resolution transmission electron microscope and energy dispersive ...spectroscopy. The size distribution, shapes, structures and elemental distribution were studied for the synthesized samples. Molecular simulation methods based on quantum mechanics have been applied to acquire the further information on their structural stability, electronic properties etc. The results show that the particle size for the pH = 4 was bimodal with an average particle size of 3.2 nm and a variance of 1.8 nm. While for pH is 7 the average is 3.9 nm about the variance increase up to 3.7 nm, and larger particles can be found. By the HREM micrographs, it is identified fcc-like clusters with a few planar defects, which may be pure Pd or Pt, or bimetallic Pd/Pt. Theoretically the most stable configuration corresponds to the Pd18Pt37 eutectic-like structure, which implies a cluster in cluster form.
En este trabajo se presenta el diseño y síntesis de nanopartículas de cromo (CrNPs) inocuas (Cr (III) y Cr (0)), mediante el método de biorreducción utilizando lirio acuático Eichhornia crassipes. ...Las CrNPs se utilizarán como material de aporte en un método alternativo de cromado por electrodeposición, donde se sustituye el baño electrolítico convencional por una solución acuosa de CrNPs reduciendo los impactos del cromado convencional. Para el diseño de la síntesis se utilizó modelado y simulación computacional para evaluar la relación de los parámetros tamaño-forma-estructura con las propiedades mecánicas superficiales asociadas a las CrNPs; obteniendo los valores necesarios para la elaboración de recubrimientos superficiales nanoestructurados. Los resultados muestran que CrNPs de 40 nm de diámetro, forma esférica y estructura cúbica centrada en el cuerpo (CCC) presentan una dureza de 10.652 GPa y 5.713 GPa para Cr y el recubrimiento de Cr-Fe respectivamente, un trabajo de adhesión de 3.1268 J/m2, y una fuerza de adhesión de 1.88656x108 N/m2; equivalentes a las obtenidas para cromado duro industrial. En la síntesis de CrNPs se utilizó un método extracelular utilizando Eichhornia crassipes. Se encontraron nanopartículas de Cr0 (53%) y Cr2O3 (43%) con un tamaño de cluster de 39 ± 7.8 nm con forma esférica. Para la caracterización de CrNPs se utilizó espectroscopia UV-visible, microscopía electrónica de transmisión y microscopia electrónica de barrido para determinar tamaño, forma y estructura de las CrNPs. Finalmente, se realizó una prueba de electrodeposición de las CrNPs biosintetizadas sobre un sustrato de hierro y se confirmó visualmente el recubrimiento superficial nanoestructurado.
The article presents an open-access code, written in CUDA® and C++ programming language, applicable for generating computational models of nanostructured surface coatings deposited by ...electrodeposition. The code uses the Schrödinger equation, energy potentials, and electrochemistry as a theoretical basis to determine the deposition and electrodeposition energies, allowing the prediction of the formation and growth of these coatings. Likewise, the parameter variation enabled within the code provides for determining the main electrodeposition parameters (voltage, current, concentration, and residence time) for experimental depositions. The code can be easily implemented for any metallic coating-substrate arrangement where the filler material is nanomaterials.
•Development of an open source in CUDA® for analysis of nanostructured coatings.•Open source to analyze the formation and growth of nanostructured metallic coatings.•Open source for custom coating-substrate model generation.
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