RESUMEN
Decontamination of unprotected skin areas is crucial to prevent excessive penetration of chemical contaminants after criminal or accidental release. A review of literature studies was performed to identify the available decontamination methods adopted to treat skin contamination after chemical, radiological and metal exposures. In this bibliographic review, an overview of the old and recent works on decontamination procedures followed in case of potential hazards substances contaminations with a comparison between these systems are provided. Almost all data from our 95 selected studies conducted in vitro and in vivo revealed that a rapid skin decontamination process is the most efficient way to reduce the risk of intoxication. The commonly-used or recommended conventional procedures are simple rinsing with water only or soapy water. However, this approach has some limitations because an easy removal by flushing may not be sufficient to decontaminate all chemical deposited on the skin, and skin absorption can be enhanced by the wash-in effect. Other liquid solutions or systems as adsorbent powders, mobilizing agents, chelation therapy are also applied as decontaminants, but till nowadays does not exist a decontamination method which can be adopted in all situations. Therefore, there is an urgent need to develop more efficient and successful decontaminating formulations.
Asunto(s)
Descontaminación/métodos , Sustancias Peligrosas/aislamiento & purificación , Piel/efectos de los fármacos , Sustancias para la Guerra Química/aislamiento & purificación , Humanos , Nanopartículas del Metal/química , Metales/aislamiento & purificación , Radioisótopos/aislamiento & purificación , Absorción Cutánea , Jabones/química , Agua/químicaRESUMEN
The pressurized liquid extraction (PLE) technique was used, for the first time, to obtain protein extracts with antioxidant activity from side streams (muscle, heads, viscera, skin, and tailfins) of gilthead sea bream (Sparus aurata) in order to give added value to these underutilized matrices. Extraction conditions previously optimized for sea bass (Dicentrarchus labrax) side streams were applied. Protein recovery percentages were 22% (muscle), 33% (heads), 78% (viscera), 24% (skin), and 26% (tailfins), which represented an increase of 1.2-4.5-fold compared to control samples (extraction by stirring). The SDS-PAGE profiles revealed that PLE-assisted extraction influenced protein molecular weight distribution of the obtained extracts. PLE conditions also allowed increasing the antioxidant capacity measured by both Trolox equivalent antioxidant capacity (TEAC; 1.3-2.4 fold) and oxygen radical absorbance capacity (ORAC; 1.9-6.4) assays for all fish extracts. Inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-qTOF-MS) were used to investigate the presence of toxic metals and mycotoxins in sea bream side streams. The levels of As, Hg, Cd, and Pb were below those established by authorities for fish muscle for human consumption (except for Cd in viscera samples). Through a nontargeted screening approach, no mycotoxins or related metabolites were detected for all sea bream side streams. This study contributes to the research on the valorization of fish processing side streams using environmentally friendly technology.
Asunto(s)
Antioxidantes/farmacología , Proteínas de Peces/farmacología , Extracción Líquido-Líquido , Dorada/metabolismo , Animales , Antioxidantes/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Proteínas de Peces/aislamiento & purificación , Manipulación de Alimentos , Metales/aislamiento & purificación , Peso Molecular , Micotoxinas/aislamiento & purificación , Capacidad de Absorbancia de Radicales de Oxígeno , Presión , Espectrometría de Masa por Ionización de Electrospray , ResiduosRESUMEN
Seventy-three samples of alcoholic beverages and juices that were purchased on the Polish market and home-made were analyzed for their elemental profiles. The levels of 23 metals were determined by ICP-MS (Ag, Ba, Bi, Cd, Co, Cr, Li, Mn, Ni, Pb, Sr and Tl), ICP-OES (Al, B, Ca, Cu, Fe, K, Mg, Na, Ti and Zn) and CVAAS (Hg) techniques in twenty-five samples of ciders widely available on the Polish market; six samples of home-made ciders; two samples of juices used in the production of these ciders; and forty samples of low-percentage, flavored alcoholic beverages based on beer. The gathered analytical data confirmed that the final elemental fingerprint of a product is affected by the elemental fingerprint of the ingredients used (apple variety) as well as the technology and equipment used by the producer, and in the case of commercial ciders, also the impact of type of the packaging used was proven. These factors are specific to each producer and the influence of the mentioned above parameters was revealed as a result of the performed analysis. Additionally, the inclusion of the home-made ciders in the data set helped us to understand the potential origin of some elements, from the raw materials to the final products. The applied statistical tests revealed (Kruskal-Wallis and ANOVA) the existence of statistically significant differences in the concentration of the following metals: Ag, Al, B, Bi, Co, Cr, Cu, Fe, K, Li, Mg, Na, Ni, Ti and Zn in terms of the type of cider origin (commercial and home-made). In turn, for different packaging (can or bottle) within one brand of commercial cider, the existence of statistically significant differences for Cu, Mn and Na was proved. The concentrations of all determined elements in the commercial cider from the Polish market and home-made cider samples can be considered as nontoxic, because the measured levels of elements indicated in the regulations were lower than the allowable limits. Moreover, the obtained results can be treated as preliminary for the potential authentication of products in order to distinguish the home-made (fake) from the authentic products, especially for premium-class alcoholic beverages.
Asunto(s)
Bebidas Alcohólicas/análisis , Malus/química , Metales/aislamiento & purificación , Oligoelementos/aislamiento & purificación , Humanos , Iones/química , Iones/aislamiento & purificación , Espectrometría de Masas , Metales/química , Polonia , Análisis Espectral , Oligoelementos/químicaRESUMEN
Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g-1), followed by sodium (695.10±9.70 mg 100 g-1), calcium (147.20±12.60 mg 100 g-1), and magnesium (97.30±2.9 mg 100 g-1). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g-1) and zinc (30.00±3.70 mg 100 g-1). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g-1 and 1706.83 mg QE 100 g-1, respectively, and possesses strong antioxidant activity of 10.54 mg mL-1. Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.
Asunto(s)
Antioxidantes/aislamiento & purificación , Fitoquímicos/aislamiento & purificación , Zea mays/química , Antioxidantes/química , Carbohidratos/química , Carbohidratos/aislamiento & purificación , Flavonoides/química , Flavonoides/aislamiento & purificación , Metales/química , Metales/aislamiento & purificación , Fenoles/química , Fenoles/aislamiento & purificación , Fitoquímicos/química , Proteínas de Plantas , Polen/químicaRESUMEN
Dielectrophoresis (DEP) is a selective electrokinetic particle manipulation technology that is applied for almost 100 years and currently finds most applications in biomedical research using microfluidic devices operating at moderate to low throughput. This paper reviews DEP separators capable of high-throughput operation and research addressing separation and analysis of non-biological particle systems. Apart from discussing particle polarization mechanisms, this review summarizes the early applications of DEP for dielectric sorting of minerals and lists contemporary applications in solid/liquid, liquid/liquid, and solid/air separation, for example, DEP filtration or airborne fiber length classification; the review also summarizes developments in DEP fouling suppression, gives a brief overview of electrocoalescence and addresses current problems in high-throughput DEP separation. We aim to provide inspiration for DEP application schemes outside of the biomedical sector, for example, for the recovery of precious metal from scrap or for extraction of metal from low-grade ore.
Asunto(s)
Electroforesis , Diseño de Equipo , Dispositivos Laboratorio en un Chip , Metales/química , Metales/aislamiento & purificación , Técnicas Analíticas Microfluídicas , Minerales/química , Minerales/aislamiento & purificación , Nanotubos de Carbono/químicaRESUMEN
In this work, the aqueous phase diagram for the mixture of the hydrophilic tributyltetradecyl phosphonium ([P44414]Cl) ionic liquid with acetic acid (CH3COOH) is determined, and the temperature dependency of the biphasic region established. Molecular dynamic simulations of the [P44414]Cl + CH3COOH + H2O system indicate that the occurrence of a closed "type 0" biphasic regime is due to a "washing-out" phenomenon upon addition of water, resulting in solvophobic segregation of the [P44414]Cl. The solubility of various metal oxides in the anhydrous [P44414]Cl + CH3COOH system was determined, with the system presenting a good selectivity for CoO. Integration of the separation step was demonstrated through the addition of water, yielding a biphasic regime. Finally, the [P44414]Cl + CH3COOH system was applied to the treatment of real waste, NiMH battery black mass, being shown that it allows an efficient separation of Co(II) from Ni(II), Fe(III) and the lanthanides in a single leaching and separation step.
Asunto(s)
Ácidos/química , Líquidos Iónicos/química , Metales/análisis , Metales/aislamiento & purificación , Compuestos Orgánicos/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificación , Interacciones Hidrofóbicas e Hidrofílicas , Compuestos Organofosforados/química , Eliminación de Residuos Líquidos/métodosRESUMEN
Accumulation of toxic metals in infants/children is of serious concern worldwide, from the viewpoint of their harmful effects on the normal growth and development. This metallomics study investigates the extent of toxic metal burdens in infants/children and the relationship to those in their mothers for 77 child/mother pair subjects. For mercury, its geometric mean concentration in infants/children was of similar level to that in their mothers, and a high-significant close correlation was observed between infants/children and their mothers (ß = 0.758, r = 0.539, p < 0.0001). A significant but less intimate mother/child relationship was observed for arsenic (ß = 0.301, r = 0.433), lead (ß = 0.444, r = 0.471) and aluminum (ß = 0.379, r = 0.451). Remarkably, the burden levels of lead, cadmium and aluminum in infants/children were approximately three times higher than those in their mothers (p < 0.0001), and the burden levels in some individuals were several tens of times higher than in the mothers. In contrast, some essential metal levels such as zinc, magnesium and calcium in infants/children were significantly lower than those in their mothers, and 29 individuals (37.7%) in the child subjects were estimated to be zinc-deficient. In addition, significant inverse correlations were observed between zinc and lead (r = -0.267, p = 0.019), and magnesium and arsenic (r = -0.514, p < 0.0001). These findings suggest that these toxic metal burdens and essential metal deficiencies in infants/children are of serious concern for their neurodevelopment, indicating that the early assessment and intervention are crucial. It is expected that larger epidemiological and intervention studies will provide a reasonable and essential pathway for intervention of neurodevelopment disorders.
Asunto(s)
Mercurio/aislamiento & purificación , Metales/toxicidad , Relaciones Madre-Hijo , Arsénico/toxicidad , Cadmio/toxicidad , Calcio/aislamiento & purificación , Calcio/toxicidad , Niño , Femenino , Humanos , Lactante , Recién Nacido , Magnesio/aislamiento & purificación , Magnesio/toxicidad , Masculino , Mercurio/toxicidad , Metales/sangre , Metales/aislamiento & purificación , Madres , Embarazo , Zinc/aislamiento & purificación , Zinc/toxicidadRESUMEN
Nanomagnetic graphene oxide modified with dopamine (GO-Fe3O4-DA) was synthesized via a very simple procedure. Using GO-Fe3O4-DA as the new adsorbent, the effervescence-assisted dispersive micro solid-phase extraction procedure was exploited for the preconcentrative extraction of Cu(ii), Pb(ii) and Ni(ii) ions. Structural characteristics of the adsorbent were studied via FT-IR, FE-SEM, EDX and XRD analyses. The rapid dispersion and high adsorption capability of GO-Fe3O4-DA, along with the rapid separation of the adsorbent from the aqueous phase by a magnet, led to a decrease in the extraction time of the target metal ions. In effect, high extraction percentages were attained in a very short time period. In this work, the relative standard deviations (RSD; n = 3) calculated for the proposed method were 1.09, 1.25 and 1.03% for the Pb(ii), Cu(ii) and Ni(ii) ions, respectively, the calibration curve was dynamically linear in the range of 0.25 to 50 µg L-1, and the limits of detection were obtained as 0.5, 0.1, and 0.7 µg L-1. The procedure was also implemented on real sausage (herbal and meaty) samples and a water sample, vouchsafing the success of the proposed method in tackling real samples with a complicated matrix.
Asunto(s)
Técnicas de Química Analítica , Dopamina , Grafito , Metales , Extracción en Fase Sólida , Dopamina/química , Grafito/química , Fenómenos Magnéticos , Metales/aislamiento & purificación , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Society's demand for metals is ever increasing while stocks of high-grade minerals are being depleted. Biomining, for example of chalcopyrite for copper recovery, is a more sustainable biotechnological process that exploits the capacity of acidophilic microbes to catalyze solid metal sulfide dissolution to soluble metal sulfates. A key early stage in biomining is cell attachment and biofilm formation on the mineral surface that results in elevated mineral oxidation rates. Industrial biomining of chalcopyrite is typically carried out in large scale heaps that suffer from the downsides of slow and poor metal recoveries. In an effort to mitigate these drawbacks, this study investigated planktonic and biofilm cells of acidophilic (optimal growth pH < 3) biomining bacteria. RNA and proteins were extracted, and high throughput "omics" performed from a total of 80 biomining experiments. In addition, micrographs of biofilm formation on the chalcopyrite mineral surface over time were generated from eight separate experiments. The dataset generated in this project will be of great use to microbiologists, biotechnologists, and industrial researchers.
Asunto(s)
Bacterias/genética , Biopelículas/crecimiento & desarrollo , Metales/aislamiento & purificación , Biología de Sistemas , Ácidos/química , Proteínas Bacterianas/genética , Cobre/aislamiento & purificación , ARN Bacteriano/genéticaRESUMEN
Metals are a finite resource and their demand for use within existing and new technologies means metal scarcity is increasingly a global challenge. Conversely, there are areas containing such high levels of metal pollution that they are hazardous to life, and there is loss of material at every stage of the lifecycle of metals and their products. While traditional resource extraction methods are becoming less cost effective, due to a lowering quality of ore, industrial practices have begun turning to newer technologies to tap into metal resources currently locked up in contaminated land or lost in the extraction and manufacturing processes. One such technology uses biology for the remediation of metals, simultaneously extracting resources, decontaminating land, and reducing waste. Using biology for the identification and recovery of metals is considered a much 'greener' alternative to that of chemical methods, and this approach is about to undergo a renaissance thanks to synthetic biology. Synthetic biology couples molecular genetics with traditional engineering principles, incorporating a modular and standardised practice into the assembly of genetic parts. This has allowed the use of non-model organisms in place of the normal laboratory strains, as well as the adaption of environmentally sourced genetic material to standardised parts and practices. While synthetic biology is revolutionising the genetic capability of standard model organisms, there has been limited incursion into current practices for the biological recovery of metals from environmental sources. This mini-review will focus on some of the areas that have potential roles to play in these processes.
Asunto(s)
Metales/aislamiento & purificación , Reciclaje , Contaminantes del Suelo/aislamiento & purificación , Biología Sintética , Contaminantes Químicos del Agua/aislamiento & purificación , Biodegradación Ambiental , Metales/química , Contaminantes del Suelo/química , Aguas Residuales/química , Contaminantes Químicos del Agua/químicaRESUMEN
The leaching of valuable metals (Co, Li, and Mn) from spent lithium-ion batteries (LIBs) was studied using subcritical water extraction (SWE). Two types of leaching agents, hydrochloric acid (HCl) and ascorbic acid, were used, and the effects of acid concentration and temperature were investigated. Leaching efficiency of metals increased with increasing acid concentration and temperature. Ascorbic acid performed better than HCl, which was attributed to ascorbic acid's dual functions as an acidic leaching agent and a reducing agent that facilitates leaching reactions, while HCl mainly provides acidity. The chemical analysis of leaching residue by X-ray photoelectron spectroscopy (XPS) revealed that Co(III) oxide could be totally leached out in ascorbic acid but not in HCl. More than 95% of Co, Li, and Mn were leached out from spent LIBs' cathode powder by SWE using 0.2 M of ascorbic acid within 30 min at 100 °C, initial pressure of 10 bar, and solid-to-liquid ratio of 10 g/L. The application of SWE with a mild concentration of ascorbic acid at 100 °C could be an alternative process for the recovery of valuable metal in spent LIBs. The process has the advantages of rapid reaction rate and energy efficiency that may benefit development of a circular economy.
Asunto(s)
Ácido Ascórbico/química , Industria Procesadora y de Extracción/métodos , Ácido Clorhídrico/química , Litio/aislamiento & purificación , Metales/aislamiento & purificación , Reciclaje/métodos , Cobalto/aislamiento & purificación , Suministros de Energía Eléctrica , Electrodos , Iones , Manganeso/aislamiento & purificación , Microscopía Electrónica de Rastreo , Espectroscopía de Fotoelectrones , Sustancias Reductoras , Temperatura , Agua/químicaRESUMEN
The aim of the study was to investigate the effect of the Fe3O4 nanoparticles (Fe-NPs) on the germination of sunflower seeds, early growth of seedlings and the concentration of selected elements in seedlings. The influence of constant magnetic fields in systems with and without Fe-NPs was investigated. Experiments were done on seeds subjected to germination under constant magnetic field (0 (control), 5, 25 and 120 mT) for 7 days in the presence of solution containing 0, 50 or 500 ppm Fe-NPs. No significant effect of Fe-NPs and the magnetic field on germination of seeds and the growth of seedlings has been demonstrated. In most cases, a decrease in germination parameters was observed. For the majority of samples the relative decrease in the concentrations of elements was demonstrated mainly for samples without Fe-NPs. Interestingly, a significant decrease in the concentrations of trivalent (including iron - Fe) and toxic elements in samples containing Fe-NPs in relation to control samples was observed. The authors suggest that in this case the binding (adsorption) of these elements in the roots and seeds of the sunflower by Fe-NPs took place. This explains the lower iron content in seedlings than in seeds prior to sowing.
Asunto(s)
Compuestos Férricos/administración & dosificación , Germinación/efectos de los fármacos , Helianthus/crecimiento & desarrollo , Campos Magnéticos , Metales/análisis , Nanopartículas/administración & dosificación , Semillas/crecimiento & desarrollo , Compuestos Férricos/química , Helianthus/efectos de los fármacos , Metales/aislamiento & purificación , Nanopartículas/química , Semillas/efectos de los fármacos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
Graphene oxide is a compound with a form similar to graphene, composed of carbon atoms in a sp2 single-atom layer of a hybrid connection. Due to its significant surface area and its good mechanical and thermal stability, graphene oxide has a plethora of applications in various scientific fields including heterogenous catalysis, gas storage, environmental remediation, etc. In analytical chemistry, graphene oxide has been successfully employed for the extraction and preconcentration of organic compounds, metal ions, and proteins. Since graphene oxide sheets are negatively charged in aqueous solutions, the material and its derivatives are ideal sorbents to bind with metal ions. To date, various graphene oxide nanocomposites have been successfully synthesized and evaluated for the extraction and preconcentration of metal ions from biological, environmental, agricultural, and food samples. In this review article, we aim to discuss the application of graphene oxide and functionalized graphene oxide nanocomposites for the extraction of metal ions prior to their determination via an instrumental analytical technique. Applications of ionic liquids and deep eutectic solvents for the modification of graphene oxide and its functionalized derivatives are also discussed.
Asunto(s)
Grafito/química , Metales/aislamiento & purificación , Nanoestructuras/química , Iones/química , Metales/química , Nanocompuestos , Compuestos Orgánicos/química , Extracción en Fase Sólida , Agua/químicaRESUMEN
Atomic force microscopy (AFM) is a consolidated technique for the study of biological systems, usually ex vivo or in culture, under different experimental conditions. Yet, the diffusion of the technique in the scientific context of histology is still rather slow and limited. In the present work, we demonstrate the potential of AFM, in terms of morphological and nanomechanical imaging, to study the effects of nano- and micro-sized metallic pollutants in living biological systems. As a model, we investigated marine molluscs (Mytilus galloprovincialis) grown in the Adriatic Sea. We characterized histological sections from two organs (gonads and digestive glands) of molluscs collected during several surveys at different growth time and distance from gas extraction platforms. We evaluated the effects of nano-pollutants mostly on the local tissue structure by combining AFM microscopy with scanning electron microscopy (SEM). Furthermore, the AFM images allowed evidencing the presence of nano- or micro-sized structures that exhibit different nanomechanical properties compared to the rest of the tissue. The results demonstrate how coupling AFM and SEM analysis can provide an effective procedure to evaluate the morphological alterations produced by the exposure to exogenous nano-pollutants in tissue and constitute a promising way to reveal basic mechanisms mediating the cytotoxicity of specific exogenous pollutants ingested by edible organisms.
Asunto(s)
Organismos Acuáticos/química , Contaminantes Ambientales/aislamiento & purificación , Metales/aislamiento & purificación , Organismos Acuáticos/efectos de los fármacos , Contaminantes Ambientales/química , Contaminantes Ambientales/toxicidad , Metales/química , Metales/toxicidad , Microscopía de Fuerza Atómica , Microscopía Electrónica de RastreoRESUMEN
Designing and development of electrochemical biosensors enable molecule sensing and quantification of biochemical compositions with multitudinous benefits such as monitoring, detection, and feedback for medical and biotechnological applications. Integrating bioinspired materials and electrochemical techniques promote specific, rapid, sensitive, and inexpensive biosensing platforms for (e.g., point-of-care testing). The selection of biomaterials to decorate a biosensor surface is a critical issue as it strongly affects selectivity and sensitivity. In this context, smart biomaterials with the intrinsic self-assemble capability like bacterial surface (S-) layer proteins are of paramount importance. Indeed, by forming a crystalline two-dimensional protein lattice on many sensors surfaces and interfaces, the S-layer lattice constitutes an immobilization matrix for small biomolecules and lipid membranes and a patterning structure with unsurpassed spatial distribution for sensing elements and bioreceptors. This review aims to highlight on exploiting S-layer proteins in biosensor technology for various applications ranging from detection of metal ions over small organic compounds to cells. Furthermore, enzymes immobilized on the S-layer proteins allow specific detection of several vital biomolecules. The special features of the S-layer protein lattice as part of the sensor architecture enhances surface functionalization and thus may feature an innovative class of electrochemical biosensors.
Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Glicoproteínas de Membrana/aislamiento & purificación , Humanos , Iones/química , Iones/aislamiento & purificación , Glicoproteínas de Membrana/química , Metales/química , Metales/aislamiento & purificación , Pruebas en el Punto de AtenciónRESUMEN
Extraction of radioactive Cs from contaminated soil is a crucial aspect of remediation after nuclear accidents. For this purpose, we have developed a new type of ligand, carbamate-conjugated catechol, to assist in metal extraction by using supercritical CO2 (SCCO2). The synthesis process for this ligand is relatively simple, and the carbamate-conjugated catechol ligand dissolves well in SCCO2. The measured ligand distribution coefficient increased according to a power law with an exponent of 1.7 as the ligand concentration increased, indicating that approximately two ligand molecules are needed to extract one Cs ion. The roles of additives (ligand, co-ligand, and water) were limited when they were used separately, but the combination of these additives was important. We tested 27 combinations of these three additives for extracting Cs from artificially contaminated sea sand. A quantitative analysis indicated that the ligand had the strongest influence on Cs extraction, followed by water, and the co-ligand. The carbamate-conjugated catechol ligand was then used for Cs extraction from artificially contaminated real soil. Three types of soil were prepared: coarse soil (particle sizeâ¯=â¯0.5-1â¯mm), medium soil (particle sizeâ¯=â¯0.2-0.5â¯mm), and fine soil (particle sizeâ¯<â¯0.2â¯mm). The Cs fractions extracted from the coarse, medium, and fine soils were measured to be 95%, 91% and 70% of the Cs fraction extracted from sea sand, respectively, which indicates the existence of a surface area effect. Additionally, we suspect that Cs undergoes chemical interaction on the surface of real soil.
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Carbamatos/química , Dióxido de Carbono/química , Catecoles/química , Cesio/aislamiento & purificación , Restauración y Remediación Ambiental/métodos , Contaminantes del Suelo/aislamiento & purificación , Ligandos , Metales/análisis , Metales/aislamiento & purificación , Tamaño de la Partícula , Suelo/química , Contaminantes del Suelo/análisis , Agua/análisis , Agua/químicaRESUMEN
Passive biochemical reactors (PBRs) represent a promising option for the treatment of mine drainage. In this study, the influence of temperature (22 and 5⯰C), salinity (0 and 20â¯g/L) and hydraulic retention time (HRT) on the efficiency of PBRs for the treatment of acidic and neutral mine drainage (AMD and NMD) was evaluated. To do so, eight 11â¯L PBRs were set-up and operated with vertically upward flow. Synthetic AMD and NMD, with two salinities (0 and 20â¯g/L), were tested at ambient temperature (22⯱â¯0.5⯰C) during the first 3 months, then at low temperature (5⯱â¯1⯰C), for 5 additional months. The HRT tested was 0.5 and 1 day, for NMD, and 2.5 and 5 days, for AMD. Results showed a consistent efficiency, above 65%, with higher HRTs (1 vs. 0.5 day for NMD and 5 vs. 2.5 for AMD). At room temperature, metals and sulfate removal was better for non-saline synthetic effluents (>99% vs 95% for Cu, 99% vs >74% for Ni, 90% vs 75% for Fe, and <99% vs <96% for SO42-), after 3 months. At 5⯰C, removal efficiency decreased especially for Ni, from 99% to 74%, for both mine drainage qualities. However, sulfate removal was found to be better in saline AMD (<40% vs <10%). The simultaneous effect of low temperature and high salinity further decreased PBR performance. Although higher HRTs entailed better removal efficiency, hydraulic problems such as decreases in permeability of the reactive mixture may still lead to inhibition of long-term PBR efficiency.
Asunto(s)
Reactores Biológicos/normas , Salinidad , Temperatura , Contaminantes Químicos del Agua/aislamiento & purificación , Frío , Concentración de Iones de Hidrógeno , Metales/aislamiento & purificación , Minería , Sulfatos/aislamiento & purificación , Contaminantes Químicos del Agua/análisisRESUMEN
A composite sorbent for the simultaneous removal of both Hg2+ and SeO32- from aqueous media was produced from the solvothermal synthesis of a zirconium metal organic framework, UiO-66, in the presence of activated carbon. The composite sorbent has a large surface area of 1051â¯m2â¯g-1 with crystalized porous structures and has strong thermal stability up to 600⯰C. The contaminant uptake of the sorbent follows a Langmuir adsorption isotherm with maximum sorption capacity of 205â¯mgâ¯g-1 and 168â¯mgâ¯g-1 for Hg2+ and SeO32-, respectively. Scanning electron microscopy-energy dispersive spectroscopy results show that the Se regions overlap exclusively with Zr-rich regions suggesting that SeO32- adsorption depends entirely on the exposed UiO-66 surface. In addition, X-ray photoelectron spectroscopy spectra of Se 3d and Hg 4f showed the association of SeO32- and Hg2+ on the UiO-66 and carbon surfaces, respectively. The sorbent could facilitate the development of a single process for the simultaneous removal of cationic Hg and anionic Se as well as other similar ionic metals with opposite charges from aqueous media.