Abstract The aim of the study was to determine the capacity of an ion exchange resin collector to concentrate anions and cations present in rainwater. An experimental quantitative methodology and various analytical techniques were applied. The results revealed that, for the analysis of anions, the presence of hydroxyl ions generates interferences, suggesting the need to use analytical techniques other than ion chromatography. In the case of cations, an acceptable recovery (70%-130%) was obtained for several elements, although not uniformly in all columns. Nickel, arsenic, cadmium and lead were identified as the most abundant elements in rainwater from forest ecosystems. These findings highlight the importance of improving the extraction process to optimize the recovery of all the elements present.

Resumen El estudio tuvo como objetivo determinar la capacidad de un colector de resinas de intercambio iónico para concentrar aniones y cationes presentes en el agua de lluvia en el Parque Natural del Señorío de Bértiz en Navarra (España). Se aplicó una metodología cuantitativa experimental y diversas técnicas analíticas. Los resultados revelaron que, para el análisis de aniones, la presencia de iones hidroxilo genera interferencias, lo que sugiere la necesidad de emplear técnicas analíticas distintas a la cromatografía iónica. En el caso de los cationes, se obtuvo una recuperación aceptable (70%-130%) para varios elementos, aunque no de manera uniforme en todas las columnas. Entre los elementos más abundantes en el agua de lluvia de los ecosistemas forestales se identificaron níquel, arsénico, cadmio y plomo. Estos hallazgos destacan la importancia de mejorar el proceso de extracción para optimizar la recuperación de todos los elementos presentes.

ABSTRACT Towards the end of 2023, the Ecuadorian government through the Agencia Nacional de Regulación, Control y Vigilancia Sanitaria (ARSA), reported lead contamination of several groceries, including milk, flour, and cinnamon, as well as their derivatives. Several laboratories and regulatory institutions had to develop and apply accurate methods for lead determination in these kinds of matrices. Here, we present an easy, low-cost method to treat food samples in order to measure Pb2⁺ and Cd2⁺ concentrations for comparative, legal, and sanitary reasons. Metal determination was made using Square Wave Anodic Stripping Voltammetry (SWASV), employing a glassy carbon electrode coated with a bismuth film into acidic medium. Experimental parameters were obtained and then a calibration curve was built. A linear relationship between peak current and lead and cadmium concentration was found; a limit of detection of 2.15 and 1.65 μM was calculated for Pb2⁺ and Cd2⁺, respectively. An intercomparison assay was also made with Atomic Absorption Spectroscopy. Finally, this electrochemical method was employed for the determination of lead and cadmium in six different food samples.

RESUMEN A finales del año 2023, el Gobierno Ecuatoriano por medio de la Agencia Nacional de Regulación, Control y Vigilancia Sanitaria (ARSA), anunció la contaminacion con plomo de varios productos de consumo, como leche, harina y canela, así como sus derivados. Varios laboratorios e instituciones regularorias desarrollaron y aplicaron metodos precisos para la determinación de este metal tóxico en este tipo de matrices. En este trabajo se presenta, un método fácil, de bajo costo para tratar muestras alimentarias y la medicion de Pb2⁺ y Cd2⁺, con fines de comparación y regulación sanitaria. La determinación de los metales tóxicos, se realizó usando voltamperometría de onda cuadrada con redisolución anódica, empleando un electrodo de carbono vítreo recubierto con películas de bismuto, en medio ácido. Con parámetros experimentales se construyó la curva de calibración, donde se encontró una relacion lineal entre la corriente de pico y la concentración de plomo y cadmio. Se obtuvo, un límite de detección de 2,15 y 1,65 μM para Pb2⁺ y Cd2⁺ respectivamente. A continuación, se realizó un ensayo de intercomparación con Espectroscopía de Absorción Atómica. Finalmente, se utilizó este método electroquímico para la determinación de plomo y cadmio en seis muestras alimenticias diferentes.

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.

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 Antecedentes. La diversa y creciente actividad antropogénica en los litorales del mundo ejerce presión en la forma y crecimiento de las conchas de diferentes moluscos bivalvos. Objetivos. Determinar los indicadores biométricos y crecimiento relativo de la concha de Saccostrea palmula y Crassostrea corteziensis en poblaciones silvestres del sureste del Golfo de California. Métodos. Se realizaron muestreos de ostiones estacionalmente (verano 2019 a primavera 2020) en las lagunas Altata (AL), Macapule (ML), Navachiste (NL) y El Colorado (ECL), Sinaloa, México (n = 300 por especie y sitio), para documentar posibles diferencias entre las medidas de la concha (longitud, altura y anchura), índices biométricos (elongación, compactación y convexidad), y alometría, con las concentraciones de los metales pesados (HM) como el arsénico (As); cadmio (Cd); cobre (Cu); hierro (Fe); plomo (Pb); y zinc (Zn) encontrados en el tejido blando de las dos especies. Resultados. Excepto para la altura, las demás dimensiones de la concha y el peso corporal presentaron diferencias significativas (p < 0.05) entre los sitios de muestreo para cada especie de ostión. La mayor elongación de la concha de S. palmula y C. corteziensis se encontró en ML y ECL, respectivamente (p < 0.05). En cada sitio de muestreo, las asociaciones morfométricas para las dos especies de ostión mostraron tendencia lineal y positiva, con diferente alometría negativa (b < 1). Las concentraciones de materia orgánica e inorgánica, así como de los HM analizados (excepto el Zn), mostraron correlaciones con algunos indicadores biométricos y alometría en los dos bivalvos, en la mayoría de las lagunas. Conclusiones. Los HM estuvieron relacionados con los indicadores funcionales de la concha y la alometría de ambos ostreidos en las diferentes lagunas.

ABSTRACT Background. The diverse and growing anthropogenic activity on the world’s coastlines puts pressure on the shape and growth of the shells of different bivalve mollusks. Goals. Determine the biometric indicators and relative growth of the shell of Saccostrea palmula and Crassostrea corteziensis in wild populations of the southeastern Gulf of California. Methods. Oyster samplings were performed seasonally (summer 2019 to spring 2020) in the Altata (AL), Macapule (ML), Navachiste (NL) and El Colorado (ECL) lagoons, Sinaloa, Mexico (n = 300 per species and site), to document possible differences between shell measurements (length, height and width), biometric indices (elongation, compaction and convexity), and allometry, with the concentrations of the heavy metals (HM) such as arsenic (As); cadmium (Cd); copper (Cu); iron (Fe); lead (Pb); and zinc (Zn) found in the soft tissue of both species. Results. Except for height, the other shell dimensions and body weight presented significant differences (p < 0.05) between the sampling sites for each oyster. The greatest shell elongation of S. palmula and C. corteziensis was found in ML and ECL, respectively (p < 0.05). At each sampling site, the morphometric associations for the two oyster species showed a linear and positive trend, with different negative allometry (b < 1). The concentrations of organic and inorganic matter as well as HM analyzed (except zinc) showed correlations with some biometric indicators and allometry in most of the lagoons in the two species. Conclusions. The HM were related to the functional indicators of the shell and allometry of both ostreids in the different lagoons.

Abstract: The study was conducted at the Jalpan de Serra dam, Querétaro, Mexico. In a mountain watershed with a history of artisanal mining activity in the upper part, runoff feeds the reservoir, transporting mining tailings. The Jalpan dam has been used for drinking water supply, agricultural irrigation activities and recreational purposes as a Ramsar site. The reason for the study has been the relevance and social impact of the reservoir sediments as a source of diffuse pollution. The objective was to determine the concentration of arsenic, cadmium and lead in the sediment and to evaluate the level of risk to human health and the environment. The methodology consists of the analysis by atomic absorption carried out in three sites sampled in the superficial layer of 10 cm depth, samples obtained with a PVC tube of 7 cm diameter, identified, preserved for transfer and digested with nitric acid. The results show mean arsenic concentrations of 4.278 mg/kg, cadmium 0.323 mg/kg and lead 4.873 mg/kg. In conclusion, the sediment analyzed does not represent a risk to human health or the environment of the reservoir according to NOM-147-SEMARNAT/SSA1-2004. This investigation demonstrates the lack of a policy or standard that establishes permissible limits for heavy metals in sediment.

Resumen: El estudio ha sido realizado en la presa Jalpan de Serra, Querétaro, México. En una cuenca de montaña con antecedentes de actividad minera artesanal en la parte alta, la escorrentía alimenta el embalse, transportando relaves mineros. La presa Jalpan se ha empleado para abastecimiento de agua de consumo humano, actividades de riego agrícola y fines recreativos como sitio Ramsar. El motivo de estudio ha sido la relevancia e impacto social que tienen los sedimentos del embalse como fuente de contaminación difusa. El objetivo ha sido conocer la concentración de arsénico, cadmio y plomo en el sedimento y evaluar el nivel de riesgo para la salud humana y del ambiente. La metodología consiste en el análisis por absorción atómica realizada en tres sitios muestreados en la capa superficial de 10 cm de profundidad, muestras obtenidas con un tubo de PVC de 7 cm de diámetro, identificadas, conservadas para su traslado y digeridas con ácido nítrico. Los resultados muestran concentraciones medias en arsénico de 4.278 mg/kg, cadmio 0.323 mg/kg y plomo 4.873 mg/kg. En conclusión, el sedimento analizado no representa riesgo para la salud humana o entorno del embalse según la norma NOM-147-SEMARNAT/SSA1-2004. Esta investigación evidencia la falta de una política o norma que establezca los límites permisibles de metales pesados en sedimentos.

RESUMEN Introducción: Hoy en día los contaminantes producidos en el agua superan las capacidades de sus mecanismos de descontaminación. Siendo necesario evaluar las aguas residuales pertenecientes al Central Refinería Ecuador. Objetivo: Evaluar la calidad del agua residual del Central Refinería Ecuador, para su posible aprovechamiento en riego agrícola. Materiales y Métodos: La calidad del agua residual se evaluó mediante ensayos físicos, químicos y microbiológicos. Resultados y Discusión: Los principales resultados físico, químicos y microbiológicos evaluados en dos momentos fueron: temperatura 46,6 y 43,6 ºC, conductividad eléctrica 2 359 y 1 366 µS cm-1, sólidos sedimentables 8 y 3,50 mL L-1. pH 5,80 y 6,30 unidades de pH, fósforo total 5 y 3,75 mg L-1, nitrógeno total 4,20 y 6,45 mg L-1, demanda química de oxígeno 1 832 y 1 742 mg L-1, demanda bioquímica de oxígeno 1 671 y 1 451 mg L-1, grasas y aceites 296,9 y 30,9 mg L-1; cadmio 0,06 y 0,16 mg L-1, cromo total 0,10 y 0,20 mg L-1, cobre 1,19 y 1,80 mg L-1, plomo 0,43 y 0,55 mg L-1, zinc 1,37 y 2,33 mg L-1, coliformes totales 8 800 000 y 1 60 000 mg L-1 y coliformes fecales 8 800 000 y 1 070 000 mg L-1. Conclusiones: El efluente no cumple con los requisitos de vertimiento de la NC 27, (2012)y es clasificada de mala calidad para ser aprovechada en el riego de la caña de azúcar según NC 855, (2011).

ABSTRACT Introduction: Nowadays the pollutants produced in water exceed the capabilities of its decontamination mechanisms. It is necessary to evaluate the wastewater belonging to the Central Refinería Ecuador (Sugar Refinery Ecuador). Objective: To evaluate the quality of the wastewater from the Central Refinería Ecuador (Sugar Refinery Ecuador) for its possible use in agricultural irrigation. Materials and Methods: The quality of the wastewater was evaluated through physical, chemical and microbiological tests. Results and Discussion: The main physical, chemical and microbiological results evaluated at two points in time were: temperature 46.6 and 43.6 ºC, electrical conductivity 2 359 and 1 366 µS cm-1, sedimentable solids 8 and 3.50 mL L-1. pH 5.8 and 6.3 pH units, total phosphorus 5 and 3.75 mg L-1, total nitrogen 4.20 and 6.45 mg L-1, chemical oxygen demand 1 832 and 1 742 mg L-1, biochemical oxygen demand 1 671 and 1 451 mg L-1, fats and oils 296.90 and 30.90 mg L-1; cadmium 0.06 and 0.16 mg L-1, total chromium 0.10 and 0.20 mg L-1, copper 1.19 and 1.80 mg L-1, lead 0.43 and 0.55 mg L-1, zinc 1.37 and 2.33 mg L-1, total coliforms 8 800 000 and 160 000 mg L-1 and fecal coliforms 8 800 000 and 1 070 000 mg L-1. Conclusions: The effluent does not comply with the discharge requirements of NC 27, (2012) and is classified of poor quality to be used for sugarcane irrigation according to NC 855, (2011).

Abstract Nonferrous metal smelting operations are a recognized source of metal accumulation in surrounding soils. In Mednogorsk, Russia, soil contamination results from atmospheric emissions from a local copper (Cu) smelter. This study aimed to assess health risks by analyzing the levels of Cu, arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in 20 Mednogorsk topsoil samples and three background area samples. The phytotoxicity of metals to Lolium perenne was also evaluated. The soil ingestion protocol of the US Environmental Protection Agency was used for health risk assessment. Phytotoxicity tests were performed on ryegrass using a standard protocol. The levels of Cu correlated with those of other elements, indicating that the smelter was the source. Of concern, the carcinogenic risk exceeded the 10−04 threshold in 85% and 15% of the samples for children under five years of age and adults, respectively. In addition, 60% of the samples exceeded the safe Pb threshold for children's health (80 mg kg−1). These risk levels are unacceptable and require specific intervention by the relevant authorities. However, only 20% of the samples showed high phytotoxicity, mostly in acidic soils (pH<4.0). This discussion focuses on the potential of soil phytostabilization to reduce human metal exposure, as the results provide valuable insights for managing metal pollution in regions affected by nonferrous smelter emissions worldwide.

Resumen Las fundiciones de metales no ferrosos son una fuente reconocida de acumulación de metales en los suelos circundantes. En Mednogorsk, Rusia, la contaminación del suelo se debe a las emisiones atmosféricas de una local fundición de cobre. Este estudio tiene como objetivo evaluar los riesgos para la salud humana mediante el análisis de los contenidos de cobre, arsénico, cadmio, plomo y zinc en 20 muestras de suelos de Mednogorsk y tres muestras de suelos del área no contaminada. Complementariamente, se evaluó la fitotoxicidad de los metales para una especie indicadora, Lolium perenne, utilizando un protocolo estándar. Para la evaluación de riesgos para la salud humana, se utilizó el protocolo de la Agencia de Protección Ambiental de los EEUU. Los contenidos de cobre se correlacionaron con los de otros elementos, lo que indica que la fundición de cobre es la fuente de emisión. Lo preocupante es que el riesgo cancerígeno superó el umbral de 10−4 en el 85% de las muestras para niños de edad <5 años y en el 15% de las muestras para los adultos. Además, el umbral de plomo considerado seguro para la salud infantil (80 mg kg−1) se superó en el 60% de las muestras. Estos niveles de riesgo son inaceptables y requieren una intervención específica por parte de las autoridades pertinentes. Sin embargo, sólo el 20% de las muestras mostraron alta fitotoxicidad en L. perenne, principalmente en suelos ácidos (con pH <4,0). Considerando estos resultados, se evalúe la factibilidad de un proceso de fitoestabilización del suelo para reducir la exposición humana a los metales. Los resultados proporcionan información valiosa para gestionar la contaminación por metales en regiones afectadas por emisiones de fundiciones no ferrosas en todo el mundo.

Anthropogenic activities in general and mining in particular, are at the root of the pollution of water resources by metals and metalloids in the Ivory Coast. These pollutants have harmful effects on the health of the population and therefore must be eliminated from the impacted water before consumption. Based on its mineralogical composition and physico-chemical properties, this study aimed to assess the capacity of Katiola clay (Côte d'lvoire) to remove metals (Hg, Pb, Cd) and arsenic in aqueous solutions. Adsorption was used to remove the chemical species. Different parameters that can influence the adsorption were studied (mass, pH, contact time and initial concentration). Relative to monometallic adsorption, the removal of chemical species decreased as follows: Pb<Hg<Cd<As. This removal reached 63.86% for Pb, 45.25% for Hg, 31.92% for Cd and 25.46% for As. The pseudo-second-order kinetic model better described the adsorption. As for the adsorption isotherms, the Langmuir model better represented the elimination of arsenic. While the Freundlich linearization better described the adsorption of metal cations (Pb, Hg and Cd). During polymetallic adsorption, lead and cadmium hindered the removal of arsenic. However, the use of the fine fraction of the clay saturated with sodium or magnesium optimized the adsorption efficiency of arsenic.

The purpose of the study was to calculate the effects of urban untreated wastewater irrigation on the heavy metals accumulation in vegetable samples consisting turnip (Brassica rapa), radish (Raphanus sativus), spinach (Spinacia olerácea), pumpkin (Cucúrbita moschata), cabbage (Brassica oleracea capitata), onion (Allium cepa), smooth luffa (Luffa aegyptiaca), coriander (Coriandrum sativum), vegetable gourd (Lagenaria siceraria) and carrot (Daucus carota subsp. sativus). This was accomplished by monitoring waste as well as fresh water-irrigated agricultural fields of Lakki Marwat, Pakistan. Flame atomic absorption spectrometer (FAAS) was used to assess the concentrations of these heavy metals. The concentration of a total of six metals including iron (Fe), zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), and cadmium (Cd) were detected and quantified in vegetable samples. Concentration of Pb was very low, while Fe concentration was higher in all the samples under investigation in the waste water-irrigated vegetables. The highest concentrations of Zn were observed in onion (441.3±2.7 mg.kg-1), and smooth luffa (293.1±0.5 mg.kg-1). Onion (361.95±2.3 mg.kg-1), turnip (292.15±5.6 mg.kg-1) and Spinach (280.25±4.8 mg.kg-1) showed exceedingly higher concentrations of Fe. Daily intakes of metals (DIM) were calculated for both adults as well as children. The DIM values for Ni and Cd exceeded the recommended value. The concentration of Fe and Zn was higher in wastewater-irrigated area samples as compared to fresh water-irrigated vegetables. The data obtained displayed a trend of heavy metal Fe>Zn>Cu>Ni>Cd>Pb. Our findings have demonstrated the accumulation of heavy metals in the vegetables irrigated by the wastewater as confirmed by flame atomic absorption spectroscopy.

RESUMEN Los pasivos ambientales mineros (PAM) son residuos con alta carga de metales que tienen el potencial de contaminar el suelo circundante, afectar negativamente la calidad del agua y aire, degradar los ecosistemas y provocar efectos tóxicos en la salud humana. Este estudio utilizó el tratamiento electroquímico como técnica de remediación para descontaminar un suelo afectado por PAM. A través de un diseño factorial mixto se investigó los efectos de las soluciones de mejora, ácido acético y ácido nítrico, y tres distancias del suelo respecto al ánodo, sobre la concentración residual y distribución espacial unidimensional de Pb, Cd y Zn. Los ensayos se realizaron por triplicado, en celdas de acrílico, durante cinco días, sometidos a 30 V de potencia y con ácido nítrico como fluido catódico. Los resultados demostraron que el ácido nítrico reduce 4.0, 11.5 y 11.3 veces el contenido de Pb, Cd y Zn en comparación con el ácido acético, es decir, que los mayores porcentajes de remoción del Pb, Zn y Cd fueron 40, 34 y 23 % respectivamente, al emplear ácido nítrico. Asimismo, la distribución espacial unidimensional de los metales en el suelo después del tratamiento, no fue un gradiente de concentración creciente desde la región anódica hacia la región catódica, sino una tendencia homogénea. Por tanto, emplear ácido nítrico como fluido de mejora confirmó la viabilidad del tratamiento electroquímico, aunque se debería potenciar en otras condiciones experimentales para alcanzar mayores tasas de remediación.

ABSTRACT Mining environmental liabilities (MEL) are metal-intensive wastes that have the potential to contaminate the surrounding soil, adversely affecting water and air quality, degrading ecosystems, and causing toxic effects on human health. This study used electrochemical treatment as a remediation technique to decontaminate soil affected by MEL. Through a mixed factorial design, the effects of the improvement solutions, acetic acid, and nitric acid, and three distances from the soil with respect to the anode, on the residual concentration and one-dimensional spatial distribution of Pb, Cd, and Zn were investigated. The tests were carried out in triplicate, in acrylic cells, for five days, submitted to 30 V of power, and with nitric acid as cathode fluid. The results showed that nitric acid reduces 4.0, 11.5, and 11.3 times the content of Pb, Cd, and Zn compared to acetic acid, that is, the highest removal percentages of Pb, Zn, and Cd were 40, 34, and 23 %, respectively, when using nitric acid. Moreover, the one-dimensional spatial distribution of metals in the post-treatment soil was not an increasing concentration gradient from the anode region to the cathodic region, but was rather a homogeneous trend. Therefore, using nitric acid as the enhancement fluid confirmed the viability of the electrochemical treatment, although it should be enhanced under other experimental conditions to achieve higher remediation rates.

Abstract The surface soil pollution of the three industrial towns of Urmia, 9 km northeast of this city, is the subject of this article. For this purpose, samples were taken from 9 points, and heavy metals such as iron, manganese, cadmium, copper, zinc, and lead has been analyzed to calculate the indicators of Geoaccumulation Index and pollution factors for these heavy metals. The background element concentration should be calculated for each element to calculate these factors. 59 samples for each element were used in the pristine areas of Urmia Plain by atomic absorption method. The presented research results show that the soil of the region is contaminated with heavy metals, so the amount of contamination for heavy metals manganese and cadmium is meager, and for the heavy metals iron and copper, they are in the middle range and for the heavy metals zinc and lead, they are in the high range. The pollution concentration around the town of expansion phase and phase 2 is more than the town of phase 1, which seems to be the cause of the food industry activity in the town of phase 1 and the activity of electronics, paint and metal industries in the expansion phase and phase 2. It seems that the high amounts of lead and zinc heavy metals in the soils around the industrial towns of Urmia are due to the activities of production units such as electronic industry, ceramics industry, metal industry, paint industry and battery production. The aforementioned industries dump their industrial waste water into the surroundings of the towns and cause soil pollution. Figure 7 shows the discharge of industrial wastewater from the expansion phase town to surrounding area. It seems that the creation of a wastewater treatment plant for polluting units and increasing the capacity of the existing treatment plant in the industrial town is important in reducing pollution.

Resumen La contaminación del suelo superficial de las tres ciudades industriales de Urmia, a 9 km al noreste de esta ciudad, es el tema de este artículo. Para ello, se tomaron muestras en 9 puntos y se analizaron metales pesados como hierro, manganeso, cadmio, cobre, zinc y plomo para calcular los indicadores del índice de geoacumulación y los factores de contaminación de estos metales pesados. Para calcular estos factores, debe calcularse la concentración de fondo de cada elemento. Se utilizaron 59 muestras para cada elemento en las zonas prístinas de la llanura de Urmia mediante el método de absorción atómica. Los resultados de la investigación presentada muestran que el suelo de la región está contaminado con metales pesados, por lo que la cantidad de contaminación para los metales pesados manganeso y cadmio es exigua, y para los metales pesados hierro y cobre, están en el rango medio y para los metales pesados zinc y plomo, están en el rango alto. La concentración de contaminación en los alrededores de la ciudad de la fase de expansión y de la fase 2 es mayor que en la ciudad de la fase 1, lo que parece deberse a la actividad de la industria alimentaria en la ciudad de la fase 1 y a la actividad de las industrias electrónica, de pinturas y metalúrgica en la fase de expansión y en la fase 2. Parece que las elevadas cantidades de metales pesados de plomo y zinc en los suelos de los alrededores de las ciudades industriales de Urmia se deben a las actividades de unidades de producción como la industria electrónica, la industria cerámica, la industria metalúrgica, la industria de pinturas y la producción de baterías. Las industrias mencionadas vierten sus aguas residuales industriales en los alrededores de las ciudades y provocan la contaminación del suelo. La figura 7 muestra el vertido de aguas residuales industriales de la ciudad en fase de expansión a los alrededores. Parece que la creación de una planta de tratamiento de aguas residuales para las unidades contaminantes y el aumento de la capacidad de la planta de tratamiento existente en la ciudad industrial son importantes para reducir la contaminación.

In recent years, various methods for surface functionalization of magnetite nanoparticles with emerging modifications have been explored and reported. Green nano-chemistry aims to synthesize nanomaterials using bio-based resources, providing new materials for biological and environmental applications. Surface modification of magnetite nanoparticles using phytochemicals extracted from plants is a fundamental principle of green synthesis routes. Agricultural waste from different crops, such as plantain pseudostem, is of particular interest as a renewable resource due to its abundant availability, low toxicity, and economic feasibility. In this study, the juice extracted from plantain pseudostem was utilized for the phytofunctionalization of magnetite nanoparticles. Characterization techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and fourier-transform infrared spectroscopy (FTIR) confirmed the nanometric dimensions of the composite (size range of 12.6 ± 3.17 nm) and established its organic-inorganic nature. The superparamagnetic properties of the composite were also demonstrated. Moreover, the potential application of this nanohybrid in bioremediation for the immobilization of cadmium(II) and lead(II) showed promising results, highlighting its efficacy in managing water pollutants. years reported nanochemistry nano chemistry biobased bio based resources applications routes crops availability toxicity feasibility study TEM, TEM , (TEM) SEM, SEM (SEM) TGA, TGA (TGA) fouriertransform fourier transform FTIR (FTIR size 126 12 6 12. 317 3 17 3.1 nm organicinorganic organic inorganic nature demonstrated Moreover cadmiumII cadmium II cadmium(II leadII lead lead(II results pollutants (TEM (SEM (TGA 1 31 3.

Two novel coordination polymers were synthesized through the reaction of the Hpcpa2- ligand (H3pcpa = N-(4-carboxyphenyl)oxamic acid) with cadmium(II) and lead(II) metal ions, yielding [Cd2(Hpcpa)2(H2O)6]n·H2O (1) and [Pb(Hpcpa)(H2O)]n (2). Structural analysis by single-crystal X-ray diffraction revealed that 1 consists of one-dimensional zigzag polymeric chains, while 2 is a three-dimensional polymer network. Additionally, investigations of their optical properties were carried out in a comparative study involving the previously reported pcpa-based coordination polymers {[Zn(Hpcpa)(H2O)3]·0.5H2O}n and {[Gd2(Hpcpa)3(H2O)5]·H2O}n], called here as 3 and 4, respectively. Under 330 nm excitation wavelength, all compounds exhibited broad emission bands spanning from 350 to 650 nm. Particularly, 1 and 3 displayed notable external quantum yields of 15.4 and 12.8%, respectively, highlighting their potential in luminescent applications. Hpcpa2 Hpcpa H3pcpa H pcpa N4carboxyphenyloxamic Ncarboxyphenyloxamic N 4 carboxyphenyl oxamic acid cadmiumII cadmium II cadmium(II leadII lead lead(II ions Cd2Hpcpa2H2O6n·H2O Cd2Hpcpa2H2O6nH2O CdHpcpaHOnHO Cd2 H2O 6 n·H2O n Cd O (1 PbHpcpaH2On PbHpcpaHOn Pb 2. . (2) singlecrystal single crystal Xray X ray onedimensional one dimensional chains threedimensional three network Additionally pcpabased based ZnHpcpaH2O3·0.5H2On ZnHpcpaH2O305H2On ZnHpcpaHOHOn Zn ·0.5H2O 0 5H2O Gd2Hpcpa3H2O5·H2On, Gd2Hpcpa3H2O5H2On GdHpcpaHOHOn Gd2 5 ·H2O , Gd {[Gd2(Hpcpa)3(H2O)5]·H2O}n] respectively 33 wavelength 35 65 Particularly 154 15 15. 128 12 8 12.8% applications carboxyphenyloxamic Cd2Hpcpa2H2O6n nH HO nH2O nHO ( PbHpcpaH On (2 ZnHpcpaH2O3 5H2On ZnHpcpaH 05H2O Gd2Hpcpa3H2O5 H2On Gd2Hpcpa3H2O5·H2On {[Gd2(Hpcpa)3(H2O)5]·H2O}n 12.8 CdHpcpaHOn ZnHpcpaHO ZnHpcpaH2O HOn GdHpcpaHO Gd2Hpcpa3H2O 12.

Resumo A acumulação de metais pesados no solo pode levar à deterioração da qualidade do solo, reduzir a fertilidade do solo e o rendimento das colheitas, ameaçando assim a saúde humana e animal. O conteúdo quantitativo de metais pesados, como chumbo (Pb), mercúrio (Hg), arsênio (As) e cádmio (Cd), foi determinado, e as concentrações de oligoelementos, como zinco (Zn), cobre (Cu), ferro (Fe) e manganês (Mn), foram calculadas para as terras consideradas contaminadas. O índice de risco ecológico potencial (IR) proposto por L. Hakanson foi utilizado no estudo de contaminação do solo por metais pesados. Como resultado, foi demonstrada a presença de oligoelementos e metais pesados nas áreas consideradas da região de Kostanay. Os valores de IR para todos os locais variaram de 137 a 447, correspondendo ao nível de classificação de risco ecológico de baixo a alto. O IR médio para As, Cd, Hg, Pb, Zn, Ni e Cu foi de 328, o que indica um alto risco ecológico. Os níveis detectados de As, Cd, Zn e Pb em áreas mineiras abandonadas há muito tempo estavam bem acima dos limites nacionais, indicando a necessidade iminente de investigar e avaliar exaustivamente a adequação da terra para posterior utilização agrícola. A disponibilidade de tais dados permitirá prever o desenvolvimento baseado em clusters de infraestruturas de processamento nas proximidades de terras agrícolas. colheitas animal , (Pb) Hg (Hg) As (As Cd (Cd) determinado (Zn) Cu, (Cu) Fe (Fe Mn, Mn (Mn) contaminadas (IR L resultado Kostanay 13 447 328 nacionais agrícola agrícolas (Pb (Hg (Cd (Zn (Cu (Mn 1 44 32 4 3

Abstract Accumulation of heavy metals in soil can lead to the deterioration of soil quality, reduce soil fertility and crop yields, and thus threaten human and animal health. The study aimed to assess the potential ecological risk of heavy metal contamination of agricultural soils in Kazakhstan. The study was carried out in 2021 on the soils of the Zhdanovskoye owner-operated farm in the Sokolovsko-Sarybai district of the Kostanay region. The quantitative content of heavy metals, such as lead (Pb), mercury (Hg), arsenic (As), and cadmium (Cd), was determined, and concentrations of trace elements, such as zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn), were calculated for the considered contaminated lands. The potential ecological risk index (RI) proposed by L. Hakanson was used in the study concerning heavy metal contamination of soil. As a result, the presence of trace elements and heavy metals in the considered areas of the Kostanay region was shown. The RI values for all sites ranged from 137 to 447, corresponding to the level of ecological risk grading from low to high. The average RI for As, Cd, Hg, Pb, Zn, Ni, and Cu amounted to 328, which indicates a high ecological risk. Detected levels of As, Cd, Zn, and Pb in long-term abandoned mining areas were well above national thresholds, indicating the impending need to fully investigate and assess the suitability of the land for further agricultural use. The availability of such data will allow predicting cluster-based development of processing infrastructures in the vicinity of agricultural lands. quality yields health Kazakhstan 202 owneroperated owner operated SokolovskoSarybai Sokolovsko Sarybai , (Pb) Hg (Hg) (As) Cd (Cd) determined Zn (Zn) Cu, (Cu) Fe, Fe (Fe) Mn, Mn (Mn) lands (RI L result shown 13 447 Ni 328 longterm long term thresholds use clusterbased cluster based 20 (Pb (Hg (As (Cd (Zn (Cu (Fe (Mn 1 44 32 2 4 3

Abstract Sorption and desorption tests were carried out for competitive and non-competitive systems with isotherms to verify the presence of Cd and Pb in soils. The soils investigated were: (i) with natural content of organic matter and (ii) with residual content of organic matter. Hydrated nitrate salts of Cd and Pb diluted in 0.01 M calcium nitrate solution in six concentrations were used for the Cd solutions and, for the solutions of Pb, five concentrations. For multi-element solutions, mixtures of the simple Cd and Pb solutions in a 1:1 ratio were used. The results of the first stage tests (i) showed good adjustments of the experimental data to the isotherms of Langmuir, Freundlich and Linear, which did not occur for the tests in stage (ii). According to the tests (i), the organic matter was the soil attribute of dominant influence in the sorting mechanisms. The parameters Qo and Kd were adequate to evaluate the adsorption of the studied metals, especially Cd. In step (ii), there was a significant increase in metal retention, especially for element Pb in the samples of Haplic Cambisol (AM) and Red-Yellow Latosol1 (RO), justified by the combined action of (1) increasing the surface area of the mineral fraction, previously covered by organic matter; and (2) increase in soil pH. The Cd element was more bioavailable in relation to the Pb. This was confirmed by the high desorption values observed for Cd. The samples of Haplic Cambisol and Red-Yellow Latosol demonstrated greater capacity to retain Cd and Pb. noncompetitive non i (i ii (ii 001 0 01 0.0 multielement multi 11 1 1: Langmuir Linear ii. . i, , mechanisms metals ii, retention AM (AM RedYellow Red Yellow RO, RO (RO) (1 fraction 2 (2 pH 00 0. (RO (