Abstract (Introduction): Vinasse is generated as a residue in the production of ethanol by fermentation-distillation of molasses/sugar cane juice, at a rate of 13 L/L of ethanol. It is an acid liquid, brown in color, characterized by high mineralization and Chemical Oxygen Demand (COD) values of up to 150 000 mg/L, being highly polluting. (Objective): The objective of this research was to evaluate a vinasse treatment process with hydrogen peroxide as a source of hydroxyl radicals at laboratory scale. (Methodology): The vinasse samples, from different distilleries in the province of Tucumán, were characterized following standardized techniques of Standard Methods. The oxidation tests were carried out with different peroxide/vinasses ratios, in a semi-batch reactor, under ambient conditions, measuring COD as an indicator parameter of the treatment. (Results): After 5 days, an 85 % decrease in COD and an increase in the Biodegradability Index were achieved. The kinetics of the oxidative reaction was first order with respect to COD, with an apparent rate constant of 0.3694 1/day. (Conclusions): Although the COD values allowed by local regulations (250 mg/L) were not reached, the proposed treatment is encouraging due to its simplicity, representing a potential option to the environmental challenge represented by vinaze in Latin America.

Resumen (Introducción): La vinaza se genera como residuo en la producción de etanol por fermentación-destilación de melazas/jugos de caña de azúcar, a razón de 13 L/L de etanol. Es un efluente líquido, ácido caracterizado por una elevada mineralización y valores de demanda química de oxígeno (DQO) de hasta 150 000 mg/L, siendo altamente contaminante. (Objetivo): Ealuar un proceso de tratamiento de vinazas con peróxido de hidrógeno, como fuente de radicales hidroxilos, en escala laboratorio. (Metodología): Las muestras de vinazas, de destilerías de la provincia de Tucumán, se caracterizaron según técnicas normalizadas de Standard Methods. Los ensayos de oxidación se realizaron con distintas relaciones de peróxido/vinaza, en un reactor semibatch, en condiciones ambientales, midiendo DQO como parámetro indicador del tratamiento. (Resultados): Al cabo de cinco días se logró una disminución de DQO del 85 % y un aumento del Índice de Biodegradabilidad. La cinética de la reacción oxidativa fue de primer orden respecto de DQO, con una constante aparente de velocidad de 0.3694 1/día. (Conclusiones): Si bien no se lograron los valores de DQO permitidos por la normativa local (250 mg/L), el tratamiento propuesto es alentador por su simpleza, representando una opción potencial al desafío ambiental que representan las vinazas en América Latina.

The present work focused on the screening process of different inorganic oxides and different temperatures for the epoxidation reaction of macaw palm vegetable oil without using solvent, a promising Brazilian biomass that can substitute other vegetable oils (e.g., soybean oil) in technological applications. This oil has an iodine value of 108.48 g of I2 per 100 g being categorized as a semi-dry oil. The epoxidized vegetable oil can be applied in manifold areas in polymer science. The epoxidation reaction here presented avoided organic solvents and organic acids and aimed to produce a greener route using metal oxides or niobium phosphate as a peroxide-activating catalyst. The experimental parameters were maintained as 10 mol% of catalyst loading and a time of 24 h; however, the temperature for some catalysts was changed to improve the epoxide conversion. Experiments were measured by proton nuclear magnetic resonance (1H NMR). Experiments using titanium oxide (TiO2) as a catalyst reached a conversion greater than 84.7%, while experiments using aluminium oxide (Al2O3) or lanthanum oxide (La2O3) achieved conversions of 22.6 and 30.1%, respectively. Furthermore, it was observed that both niobium compounds instantly react with hydrogen peroxide to form peroxy derivatives. solvent e.g., eg e (e.g. applications 10848 108 48 108.4 I semidry semi dry science peroxideactivating activating 1 mol 2 h however 1H H NMR. NMR . NMR) TiO2 TiO (TiO2 847 84 7 84.7% Al2O3 AlO Al O (Al2O3 La2O3 LaO La (La2O3 226 22 6 22. 301 30 30.1% respectively Furthermore derivatives e.g. (e.g 1084 4 108. (TiO 8 84.7 Al2O (Al2O La2O (La2O 3 30.1 e.g 84. 30.

Schiff bases are diverse organic compounds with an azomethine structure (–C=N–), holding potential in both chemistry and biology. They serve as catalysts, stabilizers, and exhibit various biological activities. The molecular structure of Schiff bases influences their biological properties, including antimicrobial effects. Redox-active compounds with more negative potentials tend to be more effective against microbes. In one of our recent studies, we explored the antimicrobial properties of two Schiff bases derivatives, SB-1 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino) and SB-2 ((E)-2-((4-nitrobenzilidene)amino)aniline). SB-1 showed antibacterial activity against certain Gram-positive bacteria, while SB-2 did not. The difference in their cyclic voltametric profiles, especially SB-1’s more negative reduction potential, prompted us to carry out further characterizations, including scan-rate studies, solvent analysis, and computational calculations. We found that SB-1, which presents a stable intramolecular hydrogen bond, undergoes irreversible oxidation, likely at the –NH2 group, and a quasi-reversible reduction via an intramolecular reductive coupling of the (–C=N–) azomethine group, supported by orbital theoretical calculations. This research sheds light on the potential applications of Schiff bases in antimicrobial contexts, guided by their redox properties and structure. –C=N–, CN –C=N– , C N biology catalysts stabilizers activities effects Redoxactive Redox active microbes studies derivatives SB1 SB 1 SB- E4amino33,5ditertbutyl2hydroxybenzylideneamino E4amino335ditertbutyl2hydroxybenzylideneamino Eaminoditertbutylhydroxybenzylideneamino E 4 amino 3 3,5 di tert butyl 2 hydroxybenzylidene 5 ((E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino SB2 E24nitrobenzilideneaminoaniline. E24nitrobenzilideneaminoaniline Enitrobenzilideneaminoaniline nitrobenzilidene aniline . ((E)-2-((4-nitrobenzilidene)amino)aniline) Grampositive Gram positive bacteria not profiles SB1s SBs s characterizations scanrate scan rate analysis calculations SB1, 1, bond oxidation NH2 NH –NH group quasireversible quasi reversible (–C=N– contexts –C=N E4amino33 5ditertbutyl2hydroxybenzylideneamino ditertbutyl hydroxybenzylideneamino 35 3, nitrobenzilideneaminoaniline ((E)-2-((4-nitrobenzilidene)amino)aniline (–C=N Eamino E4amino3 ditertbutylhydroxybenzylideneamino E4amino

The Schröeder-van Laar equation to predict the theoretical eutectic melting temperature values was applied to a set of fourteen binary mixtures (UR1 to UR14). The fourteen binary mixtures belong to a structurally diverse group of organic molecules. They are represented by the 5-membered heterocycles containing N-S and N-O rings, flexible methylene chains (RH), semi-rigid semi-fluorinated chains (RF), and hydrogen bonds (HB). A virtual screening totalizing ninety-one possible theoretical combinations was planned. The UR1 to UR14 were prepared by mixing individual components using the calculated mole fractions. The experimental (Te) and theoretical (Tt) temperatures for the eutectic melting points were determined using polarized optical microscopy (POM) and differential scanning calorimetry (DSC) techniques. Heterogeneous mixtures were formed for components with large structural diversity as seen by POM. During the melting of the mixtures, irregular behavior through the segregation of the components was recorded. The study showed that the similarities in structural diversities favor the formation of homogeneous mixtures, with Te values approaching Tt, as predicted by the Schröeder-van Laar equation and by the theory of eutectic mixtures. Liquid crystal properties were affected in homogeneous binary mixtures containing one of the individual liquid crystal components. Schröedervan Schröeder van UR (UR UR14. . UR14) molecules 5membered membered 5 NS N S NO O rings RH, RH , (RH) semirigid semi rigid semifluorinated fluorinated RF, RF (RF) HB. HB (HB) ninetyone ninety planned fractions (Te Tt (Tt POM (POM DSC (DSC techniques recorded (RH (RF (HB

Layered double hydroxides (LDHs) and related materials have been studied for a long time and their application in catalytic processes remain attractive due to the tuned properties, morphologies and metal-support interactions obtained from a variety of composition and synthesis route. In this mini-review, some important reactions, such as photocatalysis, electrocatalysis, reduction, carbon-carbon cross-couplings and water-gas shift will be emphasized along with the role of LDHs as catalysts, co-catalysts or catalytic precursors when it was clearly indicated. (LDHs properties metalsupport metal support route minireview, minireview mini review, review mini-review reactions photocatalysis electrocatalysis reduction carboncarbon carbon crosscouplings cross couplings watergas water gas catalysts cocatalysts co indicated

ABSTRACT Exposing seeds to agents that elicit tolerance to abiotic stress, such as phytohormones and organic acids, during hydration and dehydration cycles can determine their response to later stimuli, e.g. exposure to salt stress. The aim of this study was to evaluate the action of priming cycles with different eliciting agents of salt stress tolerance on seeds of the cowpea varieties Sempre Verde and Pingo de Ouro. The seeds were subjected to the following treatments: 0.0 mM NaCl (control); 100 mM NaCl (salt stress); salt stress + three seed-priming cycles (PC) in water; salt stress + PC in gibberellic acid; salt stress + PC in hydrogen peroxide; salt stress + PC in salicylic acid; salt stress + PC in ascorbic acid. The following variables were analysed: germination, growth, dry weight, salt tolerance index, total soluble sugars, total free amino acids and proline. Salt stress (100 mM NaCl) reduced germination, length and biomass accumulation in the Sempre Verde and Pingo de Ouro varieties. These showed the best response to the priming cycles with gibberellic and salicylic acids, which promoted greater germination potential, length and biomass under a salt stress of 100 mM NaCl, affording greater tolerance via osmotic regulation, especially in the Sempre Verde variety. stimuli eg e g e.g treatments 00 0 0. control (control) 10 stress) seedpriming seed (PC water acid peroxide analysed growth weight index sugars proline (10 potential regulation variety (control 1 (1 (

The emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stands for being the most serious epidemic (so far) of the 21st century. However, only a few computational studies have investigated the molecular mechanisms underlying the neutralization of the spike protein by antibodies of different classes. Hence, bioinformatic methods were employed to unravel the factors contributing to the remarkable neutralization capacity exhibited by specific antibodies. Initially, crystallographic structures of IgA monomeric / dimeric, IgG, and IgM antibodies binding with the receptor-binding domain region of the SARS-CoV-2 spike protein were retrieved. Subsequently, rigid molecular docking and molecular dynamic simulations were performed over 100 ns with explicit water solvation. Lastly, an energy decomposition was conducted to estimate the binding affinity using the last frames from molecular dynamics. The results revealed a higher binding affinity for both monomeric and dimeric forms of IgA antibodies against the spike protein. Additionally, a greater number of hydrogen bonds were observed during their interaction with the spike protein, as well as greater structural instability along the time and especially a more thermodynamically favorable interaction affinity. In this way, the research contributes a small piece to the complex puzzle of understanding the humoral immune response induced by the SARS-CoV-2 virus. SARSCoV2 SARSCoV SARS CoV (SARS-CoV-2 so far st century However classes Hence Initially IgG receptorbinding receptor SARS-CoV- retrieved Subsequently 10 solvation Lastly dynamics Additionally way virus (SARS-CoV- SARS-CoV 1 (SARS-CoV

Computational predictive approaches present themselves as an attractive alternative in the search for new compounds that may present toxic or growth regulatory activity in Aedes aegypti. Aspergillus species is a producer of secondary metabolites with diverse biological activities. In this study, it was possible to evaluate the pharmacokinetic and toxicological properties in silico, as well as the prediction of the insecticidal biological activities of the juvenile hormone of natural substances produced by the genus Aspergillus. Initially, 187 molecules were cataloged from various species of Aspergillus spp., and only seven molecules of indole alkaloids were found to exhibit a toxic dose 50% (TD50) after conducting toxicity predictions. The molecular dynamic simulation trajectories were utilized to study parameters such as root mean square deviation, root mean square fluctuation, radius of gyration and intermolecular hydrogen bond to understand the behavior and stability of proposed compounds in the binding pocket of the target protein. The N-β-acetyltryptamine molecule showed a binding affinity value of –8.100 ± 0.200 kcal mol-1, which classifies the compound as a potential insecticidal agent against the Aedes aegypti vector. silico Initially 18 spp spp. 50 TD50 TD (TD50 predictions deviation fluctuation protein Nβacetyltryptamine N β acetyltryptamine 8100 8 100 –8.10 0200 0 200 0.20 mol1, mol1 mol 1, 1 mol-1 vector 5 TD5 (TD5 810 10 –8.1 020 20 0.2 mol- (TD 81 –8. 02 2 0. –8 –

The in silico study aimed to suggest phytochemicals from Commiphora leptophloeos leaves essential oil as therapies against coronavirus disease (COVID-19) (or severe acute respiratory syndrome coronavirus 2, SARS-CoV-2). For that, we used molecular docking (MD), absorption, distribution, metabolism, excretion, and toxicity (ADMET) parameters, and pharmacokinetic analysis. MD showed the presence of hydrophobic and hydrogen bonds for nine compounds. β-Selinene and bicyclogermacrene showed the best interaction values with the protein Mpro (ID: 6Y2F) (-5.9) and chimeric receptor complexed with its receptor human ACE2 (ID: 6VW1) (-6.1 and -5.5) proteins, as well as low gastrointestinal and high epithelial absorptions, medium permeability for Caco-2 cells and high epithelial permeability, low oral excretion, and were inhibitors of CYP2C19 and CYP2C9 enzymes. On the other hand, both were not permeable to the blood-brain barrier and inhibitors or substrates for glycoprotein-D, and showed carcinogenic potential, but only β-selinene was considered mutagenic. Although little bioavailable, both presented aspects structurally adequate, being compounds with moderate synthesis difficulty. Therefore, more analyses are necessary to evaluate the mechanism of action and unsatisfactory parameters foreseen in bioinformatic assays. COVID19 COVID 19 (COVID-19 2 SARSCoV2. SARSCoV2 SARSCoV SARS CoV . SARS-CoV-2) that MD, , (MD) absorption distribution metabolism excretion ADMET (ADMET analysis βSelinene β Selinene ID (ID 6Y2F YF Y F 5.9 59 5 9 (-5.9 ACE 6VW1 VW 6.1 61 6 1 (-6. 5.5 55 -5.5 proteins absorptions Caco2 Caco Caco- CYPC CYP C CYP2C1 CYP2C enzymes hand bloodbrain blood brain glycoproteinD, glycoproteinD glycoprotein D, D glycoprotein-D potential βselinene selinene mutagenic bioavailable adequate difficulty Therefore assays COVID1 (COVID-1 SARS-CoV-2 (MD 5. (-5. 6VW 6. (-6 -5. (COVID- SARS-CoV- (-5 (- -5 (COVID SARS-CoV ( -

In this work, using the PM3 semi-empirical method, the oxidation of the single-walled carbon nanotube (SWCNT) was studied by sulfuric and nitric acid for the incorporation of carbonyl (C=O), phenol (OH) and carboxylic (COOH) groups in the C=C bonds present on the surface of the nanotube. Subsequently, the crosslinking of the oxidized SWCNT (SWCNTox) and chitosan (Q) was observed through hydrogen bonds of the C=O and OH bonds with 2.34 Å, the process was endothermic and soluble in polar solvents due to the presence of OH and NH groups in the structure of SWCNTox/Q. The Monte Carlo modeling allowed to study the adsorption of pesticides in the SWCNTox/Q at different temperatures, where the QSAR (quantitative structure activity relationship) properties allowed predicting the behavior of the pesticides, that is, the degree of hydrophobicity (log P) and accessible surface area (ASA) were important parameters in the evaluation of SWCNTox/Q as an adsorbent and surface interacting with pesticides respectively. Finally, the adsorption was a physisorption process due to the electronegativity of the CO, OH, NH2, NH and C=O bonds. work PM semiempirical semi empirical method singlewalled single walled (SWCNT C=O, CO , C O (C=O) (OH COOH (COOH CC Subsequently SWCNTox (SWCNTox Q (Q 234 2 34 2.3 Å SWCNToxQ temperatures quantitative relationship is log P ASA (ASA respectively Finally NH2 (C=O 23 3 2.

Groundwater is considered an important source of water aid for human consumption. However, this water can be contaminated by impurities, such contamination spots that might reach the water tables. The aim of this study was to investigate the quality of shallow groundwater in Flores neighborhood, located in the municipality of Benevides, within Belém metropolitan region, State of Pará, Brazil. Recommendations described in Standard Methods for Examination of Water and Wastewater were followed at the time to determine physical-chemical parameters such as potential hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), apparent color, turbidity, total hardness (TH), ions and trace elements. Multivariate statistical analysis has shown that most predictive water-quality parameters set for human consumption are associated with natural events involving weathering and leaching processes. Nevertheless, parameters of nitrate, phosphate, EC, TDS and pH are also influenced by anthropic conditions in the surroundings, mainly phosphate and nitrate ions. Therefore, it can be concluded that shallow groundwaters in Flores neighborhood are unsuitable for human consumption, making it necessary for municipal public authorities to take action to solve the problem of water shortage in the borough, thus preventing the population from use those shallow groundwaters, as their consumption can bring health problems. However impurities tables Benevides region Pará Brazil physicalchemical physical chemical pH, , (pH) EC (EC) TDS, (TDS) color turbidity TH, TH (TH) elements waterquality processes Nevertheless surroundings Therefore borough problems (pH (EC (TDS (TH

RESUMO Santa Catarina é um importante produtor de banana, responsável por 722 toneladas anuais. Para cada 1.000 kg de banana colhida, são gerados aproximadamente 3.000 kg de pseudocaule, 650 kg de cascas e 350 kg de frutos rejeitados. Estudos avaliaram a utilização de resíduos de banana para produção de bioetanol. Resíduos sólidos como bagaço de pseudocaule de banana, cascas de banana e vinhaça (resíduo de caldo fermentado) são produzidos nesse processo. Este estudo teve como objetivo quantificar e caracterizar esses resíduos para produção de biogás e metano. Cascas de banana e vinhaça foram melhores por conterem menor teor de sólidos totais e relações C:N (carbono:nitrogênio) favoráveis (10 - 30:1), proporcionando maior potencial bioquímico de metano (260 mLCH4 gvs -1) em comparação ao pseudocaule de bananeira bagaço (201 mLCH4 gvs -1). No entanto, a vinhaça apresentou alto teor de sulfeto de hidrogênio (0,0783%), necessitando de dessulfurização do biogás gerado para seu uso seguro. No geral, os resultados indicam que o bagaço do pseudocaule da banana, as cascas de banana e a vinhaça têm potencial substancial para a produção de biogás e metano devido às suas altas taxas de degradação. A composição do biogás atende aos critérios de utilização, com concentrações adequadas de metano e dióxido de carbono, destacando a viabilidade desses resíduos para geração de energia e contribuindo para a sustentabilidade no cultivo da banana. 72 anuais 1000 1 000 1.00 colhida 3000 3 3.00 65 35 rejeitados bioetanol resíduo fermentado processo CN C N carbononitrogênio carbono nitrogênio (carbono:nitrogênio 10 (1 301, 301 30 , 30:1) 260 (26 mLCH -1 201 (20 1. . entanto 0,0783%, 00783 0,0783% 0 0783 (0,0783%) seguro geral degradação 7 100 00 1.0 300 3.0 6 ( 30:1 26 (2 20 0078 0,0783 078 (0,0783% 3. 30: 2 007 0,078 07 (0,0783 0,07 (0,078 0,0 (0,07 0, (0,0 (0, (0

ABSTRACT Santa Catarina is a significant banana producer, responsible for 722 tons annually. For every 1,000 kg of bananas harvested, approximately 3,000 kg of pseudostem, 650 kg of peels, and 350 kg of rejected fruit are generated. Studies have evaluated the use of banana residues for bioethanol production. Solid residues like banana pseudostem bagasse, banana peels, and vinasse (fermented broth residue) are produced during this process. This study aimed to quantify and characterize these residues for biogas and methane production. Banana peels and vinasse were more suitable for containing lower total solids content and favorable C:N (carbon:nitrogen) ratios (10-30:1), yielding higher biochemical potential of methane (260 mLCH4 gvs -1) compared to banana pseudostem bagasse (201 mLCH4 gvs -1). However, vinasse had a high hydrogen sulfide content (0.0783%), necessitating desulphurization for safe biogas use. The results indicate that banana pseudostem bagasse, banana peels, and vinasse have substantial potential for biogas and methane production due to their high degradation rates. The biogas composition meets the criteria for use, with adequate methane and carbon dioxide concentrations, highlighting the viability of these residues for energy generation and contributing to sustainability in banana cultivation. producer 72 annually 1000 1 000 1,00 harvested 3000 3 3,00 65 35 generated fermented residue process CN C N carbonnitrogen nitrogen (carbon:nitrogen 10301, 10301 10 30 , (10-30:1) 260 (26 mLCH -1 201 (20 1. . However 0.0783%, 00783 0.0783% 0 0783 (0.0783%) rates concentrations cultivation 7 100 00 1,0 300 3,0 6 1030 (10-30:1 26 (2 - 20 0078 0.0783 078 (0.0783% 1, 3, 103 (10-30: 2 ( 007 0.078 07 (0.0783 (10-30 0.07 (0.078 (10-3 0.0 (0.07 (10- 0. (0.0 (10 (0. (1 (0

Summary: Currently, agricultural activity is constantly threatened by the effects of climate change and radical expression of environmental factors as irregular rainfall distribution responsible for water availability and deficit. These factors generate water stress in productive systems, whose negative effect is reflected on morphological, physiological and biochemical aspects of vegetative growth. The use of biostimulants arises as a strategy to counteract this impact, improving crop efficiency in the use of resources and generating responses, as metabolite production, among other substances that mitigate the effects of oxidative stress. In this context, waxes, hydrogen peroxide (H2O2), salicylic acid (SA) and ALGAENZIMSMR were used on raspberry plants subjected to moderate water stress (-0. 8 MPa) to evaluate the fruit response in aspects of vegetative growth, physiological and biochemical quality. For the establishment, a completely randomized design was used with 5 treatments: Green Cover as 5 mL L-1, H2O2 10-4 M, salicylic acid 0.27 mM, ALGAENZIMSMR 7.5 mL L-1 and the control with 50% recovery of the transpired volume as well as water potential similar to the rest of plants and 4 replicates. The results showed that waxes, SA and algal extract increased the photosynthetic rate; the four treatments increased root length; waxes increased root height; and H2O2 increased root biomass. Compared to the control, higher levels of vitamin C and anthocyanins were produced in fruits - a very important aspect due to the functionality of these compounds in human health. Therefore, the use of these biostimulants are a very useful tool for crop management in environments with water restriction.

Resumen: En la actualidad la actividad agrícola se ve amenazada constantemente por los efectos del cambio climático y la expresión radical de los factores ambientales, como la irregularidad en la distribución pluvial responsable de la disponibilidad del agua y déficit, que genera estrés hídrico en los sistemas productivos, cuyo efecto negativo se refleja en aspectos de crecimiento vegetativo, morfológicos, fisiológicos y bioquímicos. El uso de bioestimulantes surge como estrategia para contrarrestar este impacto, mejorando la eficiencia de los cultivos en el uso de los recursos y generar respuestas, como la producción de metabolitos entre otras sustancias, que mitigan los efectos del estrés oxidativo. Bajo este contexto se planteó el uso de ceras, peróxido de hidrogeno (H2O2), ácido salicílico (AS) y algaenzims, sobre plantas de frambuesa sometidas a estrés hídrico moderado (-0.8 MPa) con el objetivo de evaluar la respuesta en aspectos de crecimiento vegetativo, fisiológicos y calidad bioquímica de frutos, para el establecimiento se empleó un diseño completamente al azar con 5 tratamientos: greencover as® 5 mL L-1, H2O2 10-4 M, ácido salicílico 0.27 mM, algaenzims® 7.5 mL L-1 y el control con recuperación del 50% del volumen transpirado y con potencial hídrico similar al resto de plantas y 4 repeticiones. Como resultados se obtuvo que las ceras, AS y el extracto de algas incrementaron la tasa fotosintética, los cuatro tratamientos aumentaron la longitud de raíces, las ceras la altura, y el H2O2 la biomasa de raíz. Por otro lado, en comparación con el control, se produjeron mayores niveles de vitamina C y antocianinas en frutos, un aspecto muy importante por la funcionalidad de estos compuestos en la salud humana. Por lo tanto, el uso de estos bioestimulantes se puede visualizar como una herramienta de gran utilidad para el manejo de cultivos en ambientes con restricción de agua.

Summary: The municipality of Medellín, Veracruz, México has a type A landfill, whose operation level has recently increased due to landfill closure in the city of Veracruz. The objective of this study is to analyze and evaluate the quality of groundwater surrounding the landfill of the municipality of Medellín., such as hydrogen potential (pH), electrical conductivity (EC), turbidity (T), chemical oxygen demand (COD), total phosphorus (TP), nitrates (NO3 -), total dissolved solids (TDS) and heavy metals Lead (Pb), cadmium (Cd) and copper (Cu) in seven groundwater wells near the landfill during the “north” and dry season. The physicochemical water results from the seven wells analyzed were within the maximum permissible limits of Mexican regulations: turbidity values exceeded international regulations and four wells were found contaminated according to COD levels. The concentrations of Pb and Cd in both seasons were higher than the maximum permissible limits for human consumption in accordance with national and international regulations. Therefore, the results indicated the negative influence of the landfill on groundwater quality.

Resumen: Los rellenos sanitarios se han vuelto una fuente de contaminación de aguas superficiales y subterráneas, debido a la generación de lixiviados que pueden llegar hasta los cuerpos de agua con efectos adversos al ambiente. El municipio de Medellín, Veracruz, México; cuenta con un relleno sanitario tipo A cuyo nivel de operación se ha incrementado recientemente debido a la clausura del relleno sanitario de la ciudad de Veracruz. El objetivo del presente estudio fue analizar la calidad del agua subterránea aledaña al relleno sanitario del municipio de Medellín. Se evaluaron potencial de hidrógeno (pH), conductividad eléctrica (CE), turbidez (T), Demanda Química de Oxigeno (DQO), Fósforo Total (PT), Nitratos, (NO3 -), Sólidos Disueltos Totales (SDT) y metales pesados Plomo (Pb), Cadmio (Cd) y Cobre (Cu) en 7 pozos de agua subterránea próximos al relleno sanitario durante la temporada de “nortes” y estiaje. Los resultados fisicoquímicos del agua de los 7 pozos analizados se encontraron dentro de los límites máximos permisibles de la normatividad mexicana; los valores de turbidez superaron la normatividad internacional y 4 pozos mostraron estar contaminados de acuerdo a los niveles de DQO. Las concentraciones de Pb y Cd en ambas temporadas se encontraron superiores a los límites máximos permisibles para consumo humano de acuerdo con la normatividad nacional e internacional. Los resultados indicaron la influencia negativa del relleno sanitario en la calidad del agua subterránea.

ABSTRACT Soil contamination with toxic metals brings along severe environmental issues. Among these metals, copper (Cu) is harmful to plant development when it reaches high contamination levels in the soil. Thus, identifying species capable of resisting this contamination type helps these sites’ revegetation and decontamination processes. Therefore, the present study aimed to investigate the tolerance of Cedrela fissilis plants to excess Cu through morphophysiological and biochemical variables. C. fissilis seedlings were subjected to five concentrations of Cu (0, 2, 4, 6, and 8 mg L-1). The experimental design was completely randomized, with five treatments and four repetitions. Morphophysiological (number of leaves, shoot height, root length, dry weight, morphological variables of the root system, and leaf area) and biochemical (antioxidant enzymes, lipid peroxidation, hydrogen peroxide concentration, and photosynthetic pigments) traits and Cu accumulated in roots and shoot were evaluated. High concentrations of Cu had a negative effect on the shoot and root dry weight, photosynthetic rate, stomatal conductance, and transpiration rate. Overall, Cu increased the activity of the antioxidant enzymes and lipid peroxidation. Therefore, Cu incidence in the nutrient solution has negatively influenced the biochemical and physiological traits of C. fissilis seedlings to the detriment of their growth. Thus, it was possible to identify sensitive behavior by the investigated species. Because of these features, C. fissilis seedlings can be used as markers for copper-contaminated areas. issues (Cu soil Thus sites processes Therefore C 0, 0 (0 2 4 6 L1. L1 L 1 . L-1) randomized repetitions number leaves height length weight system area peroxidation concentration pigments evaluated rate conductance Overall growth features coppercontaminated contaminated areas ( L-1 L-

RESUMO A contaminação do solo com metais tóxicos traz consigo graves problemas ambientais. Dentre esses metais, o cobre (Cu) é prejudicial ao desenvolvimento das plantas quando atinge elevados níveis de contaminação no solo. Assim, identificar espécies capazes de resistir a esse tipo de contaminação auxilia nos processos de revegetação e descontaminação desses locais. Portanto, o presente estudo teve como objetivo investigar a tolerância de plantas de Cedrela fissilis ao excesso de Cu através de variáveis morfofisiológicas e bioquímicas. Mudas de C. fissilis foram submetidas a cinco concentrações de Cu (0, 2, 4, 6 e 8 mg L-1). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Características morfofisiológicas (número de folhas, altura da parte aérea, comprimento da raiz, massa seca, variáveis morfológicas do sistema radicular e área foliar) e bioquímicas (enzimas antioxidantes, peroxidação lipídica, concentração de peróxido de hidrogênio e pigmentos fotossintéticos) e Cu acumulado nas raízes e folhas foram avaliados. Altas concentrações de Cu tiveram efeito negativo no peso seco da parte aérea e das raízes, na taxa fotossintética, na condutância estomática e na taxa transpiratória. No geral, o Cu aumentou a atividade das enzimas antioxidantes e a peroxidação lipídica. Portanto, a incidência de Cu na solução nutritiva influenciou negativamente as características bioquímicas e fisiológicas das mudas de C. fissilis em detrimento do seu crescimento. Assim, foi possível identificar o comportamento sensível da espécie investigada. Devido a essas características, mudas de C. fissilis podem ser utilizadas como bioindicadoras de áreas contaminadas por cobre. ambientais (Cu Assim locais Portanto C 0, 0 (0 2 4 L1. L1 L 1 . L-1) casualizado repetições número raiz seca foliar lipídica fotossintéticos avaliados fotossintética transpiratória geral crescimento investigada ( L-1 L-