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1.
Viruses ; 13(3)2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33807081

RESUMEN

The emergent human coronavirus SARS-CoV-2 and its high infectivity rate has highlighted the strong need for new disinfection systems. Evidence has proven that airborne transmission is an important route of spreading for this virus. Therefore, this short communication introduces CLODOS Technology®, a novel strategy to disinfect contaminated surfaces. It is a product based on stable and 99% pure chlorine dioxide, already certified as a bactericide, fungicide and virucide against different pathogens. In this study, CLODOS Technology®, by direct contact or thermonebulization, showed virucidal activity against the human coronavirus HCoV-229E at non-cytotoxic doses. Different conditions such as nebulization, exposure time and product concentration have been tested to standardize and optimize this new feasible method for disinfection.


Asunto(s)
Coronavirus Humano 229E/efectos de los fármacos , Desinfectantes/farmacología , Desinfección/métodos , Línea Celular , Compuestos de Cloro/análisis , Compuestos de Cloro/farmacología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Desinfectantes/análisis , Desinfección/instrumentación , Humanos , Nebulizadores y Vaporizadores , Óxidos/análisis , Óxidos/farmacología
2.
Ecotoxicol Environ Saf ; 208: 111624, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396144

RESUMEN

Phthalate esters (PAEs), such as dibutyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), are used extensively as additives and plasticizers, and have become ubiquitous in the environment. PAEs in the soil could have adverse effects on crop plants as well as humans via accumulations in food chain. Thus, it is important to explore strategies to reduce the bioavailability of phthalate esters. We investigated the effects of Fe-Mn oxide-modified biochar composite (FMBC) applications on the quality of wheat grown in DBP- and DEHP-polluted brown soil. The application of FMBC and biochar (BC) increased the wheat grain biomass by 9.71-223.01% and 5.40-120.15% in the DBP-polluted soil, and 10.52-186.21% and 4.50-99.53% in the DEHP-spiked soil in comparison to the controls. All FMBC treatments were better than the BC treatments, in terms of decreasing DBP and DEHP bioavailability for the wheat grains. The activities of the glutamine synthetase and glutamic-pyruvic transaminase in the flag leaves at the filling stage and of granule-bound starch synthase, soluble starch synthase, and adenosine diphosphate-glucose pyrophosphorylase in the grains at maturity increased significantly with increases in either the BC or FMBC applications. This, in turn, increased the starch, protein, and amino acid content in the wheat grains. Compared with the BC treatment, the FMBC amendment induced only slight increases in the aforementioned factors. This study offers novel insights into potential strategies for decreasing PAEs bioavailability in soil, with potential positive implications for crop quality and environmental health improvements.


Asunto(s)
Carbón Orgánico/química , Restauración y Remediación Ambiental/métodos , Ácidos Ftálicos/química , Contaminantes del Suelo/metabolismo , Triticum/fisiología , Dibutil Ftalato/análisis , Dibutil Ftalato/metabolismo , Dietilhexil Ftalato/metabolismo , Grano Comestible/química , Contaminación Ambiental , Ésteres/análisis , Humanos , Hierro/análisis , Óxidos/análisis , Plastificantes/análisis , Suelo/química , Contaminantes del Suelo/análisis , Triticum/metabolismo
3.
Environ Geochem Health ; 43(5): 2065-2080, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33392897

RESUMEN

This paper attempts to evaluate the mineralogical and chemical composition of sedimentary limestone mine waste alongside its mineral carbonation potential. The limestone mine wastes were recovered as the waste materials after mining and crushing processes and were analyzed for mineral, major and trace metal elements. The major mineral composition discovered was calcite (CaCO3) and dolomite [CaMg(CO3)2], alongside other minerals such as bustamite [(Ca,Mn)SiO3] and akermanite (Ca2MgSi2O7). Calcium oxide constituted the greatest composition of major oxide components of between 72 and 82%. The presence of CaO facilitated the transformation of carbon dioxide into carbonate form, suggesting potential mineral carbonation of the mine waste material. Geochemical assessment indicated that mean metal(loid) concentrations were found in the order of Al > Fe > Sr > Pb > Mn > Zn > As > Cd > Cu > Ni > Cr > Co in which Cd, Pb and As exceeded some regulatory guideline values. Ecological risk assessment demonstrated that the mine wastes were majorly influenced by Cd as being classified having moderate risk. Geochemical indices depicted that Cd was moderately accumulated and highly enriched in some of the mine waste deposited areas. In conclusion, the limestone mine waste material has the potential for sequestering CO2; however, the presence of some trace metals could be another important aspect that needs to be considered. Therefore, it has been shown that limestone mine waste can be regarded as a valuable feedstock for mineral carbonation process. Despite this, the presence of metal(loid) elements should be of another concern to minimize potential ecological implication due to recovery of this waste material.


Asunto(s)
Carbonato de Calcio , Residuos Industriales/análisis , Minería , Carbonato de Calcio/análisis , Compuestos de Calcio/análisis , Compuestos de Calcio/química , Dióxido de Carbono/química , Carbonatos/análisis , Carbonatos/química , Monitoreo del Ambiente , Contaminación Ambiental , Magnesio/análisis , Malasia , Metales Pesados/análisis , Minerales/análisis , Óxidos/análisis , Óxidos/química , Oligoelementos/análisis
4.
Environ Microbiol ; 23(2): 1210-1221, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33325106

RESUMEN

Planktonic microorganisms play a key role in the biogeochemical processes of the aquatic system, and they may be affected by many factors. High-throughput sequencing technology was used in this study to investigate and study the bacterioplankton community of water bodies in the upper reaches of the Heihe River Basin in Qinghai Plateau. Results showed that Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the predominant phyla in this river section, while the main genera are Thiomonas, Acidibacillus, Acidocella, Rhodanobacter, Acidithiobacter and Gallionella, which are autochthonous in the acid-mine drainage. Additionally, total nitrogen, total phosphorus, permanganate index and pH are significantly correlated with the bacterioplankton abundance and are the main limiting factors for the spatial distribution of the bacterioplankton. PICRUSt inferred that the mainstream microbial assemblages had a higher abundance of KOs belong to metabolism of terpenoids and polyketides, while the tributary had higher abundance of KOs belong to the immune system. The relationship between bacterioplankton community composition and environmental factors in the Heihe River basin was discussed for the first time in this study, which provides a theoretical basis for the healthy, orderly development of the water environment in the Heihe River Basin.


Asunto(s)
Bacterias/aislamiento & purificación , Microbiota , Plancton/aislamiento & purificación , Ríos/química , Ríos/microbiología , Bacterias/clasificación , Bacterias/genética , China , Concentración de Iones de Hidrógeno , Compuestos de Manganeso/análisis , Redes y Vías Metabólicas/genética , Nitrógeno/análisis , Óxidos/análisis , Fósforo/análisis , Plancton/clasificación , Plancton/genética
5.
Ecotoxicol Environ Saf ; 203: 111010, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32888587

RESUMEN

Manganese (Mn) toxicity is common in plants grown on very acid soils. However, some plants species that grow in this condition can take up high amounts of Mn and are referred to as hyperaccumulating species. In this study, we evaluated the capacity of Ilex paraguariensis to accumulate Mn and the effect of excessive concentrations on plant growth and nutrition. For this, a container experiment was conducted using soils from different parent materials (basalt and sandstone), with and without liming, and at six doses of applied Mn (0, 30, 90, 270, 540 and 1,080 mg kg-1). Clonal plants grown for 203 days were harvested to evaluate yield, and leaf tissue samples were evaluated for Mn and other elements. Without liming and with high Mn doses, leaf Mn concentrations reached 13,452 and 12,127 mg kg-1 in sandstone and basalt soils, respectively; concentrations in excess of 10,000 mg kg-1 are characteristic of hyperaccumulating plants. Liming reduced these values to 7203 and 8030 mg kg-1. More plant growth accompanied increased Mn leaf concentrations, with a growth reduction noted at the highest dose in unlimed soils. Elemental distribution showed Mn presence in the mesophyll, primarily in vascular bundles, without high Mn precipitates. Interveinal chlorosis of young leaves associated with high Mn concentration and lower Fe concentrations was observed, especially in sandstone soil without liming. However, the occurrence of this symptom was not associated with decreased plant growth.


Asunto(s)
Ácidos/farmacología , Ilex paraguariensis/metabolismo , Manganeso/metabolismo , Enfermedades de las Plantas/inducido químicamente , Contaminantes del Suelo/metabolismo , Ácidos/análisis , Compuestos de Calcio/análisis , Compuestos de Calcio/farmacología , Ilex paraguariensis/efectos de los fármacos , Ilex paraguariensis/crecimiento & desarrollo , Hierro/metabolismo , Manganeso/análisis , Manganeso/toxicidad , Óxidos/análisis , Óxidos/farmacología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
6.
Chemosphere ; 251: 126626, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32443247

RESUMEN

Three spectrophotometric methods have been developed and compared for the quantification of low concentrations (0.03-63 µM) of aqueous permanganate in neutral pH conditions. Although permanganate is a widely used oxidant in drinking water and wastewater treatment, no widely accepted method of quantification has been reported to date. While one method presented does not require the need for any reagent chemicals (direct spectrophotometric analysis), it yielded a relatively low molar absorption coefficient of 3340 M-1 cm-1 at 525 nm and a level of detection (LOD) and quantification (LOQ) of 0.45 and 1.51 µM, respectively. Some instability of permanganate species during direct quantification was found to occur over 60 min, with a total decrease of 0.002 (arbitrary units) of absorbance, equivalent to a decrease in concentration of 0.6 µM. Beyond 60 min, no further degradation was observed. Indirect spectrophotometric analyses using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and sodium iodide (NaI) provided a significantly more sensitive method for permanganate quantification, yielding molar absorption coefficients of 140,030 and 61,130 M-1 cm-1, respectively. The LOD and LOQ were determined to be 0.01 and 0.03 µM for the ABTS method and 0.02 and 0.08 µM for the NaI method, respectively. Although conservative and accurate limits of quantification for both the ABTS and NaI methods are presented, which should be sufficient of most practical applications, lower limits may be possible with further refinement of the methods.


Asunto(s)
Compuestos de Manganeso/análisis , Óxidos/análisis , Espectrofotometría/métodos , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Concentración de Iones de Hidrógeno , Indicadores y Reactivos , Límite de Detección , Estándares de Referencia , Espectrofotometría/instrumentación
7.
Chemosphere ; 257: 127147, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32473410

RESUMEN

In this report, the adsorption of Cr(VI) onto MnO2/CS nanocomposite material from aqueous solution is investigated. All the factors, which affect the adsorption, such as pH, adsorption time, Cr(VI) initial concentration and adsorbent dosage, are also examined. The results obtained show that the Cr(VI) uptake is strongly affected by pH and ion strength. Analysis within the nonlinear isotherm models indicates that the Sips isotherm combining with the Langmuir and Freundlich models offer the best fit to the experimental data due to the obtained highest R2 and smallest RMSE and χ2 values. The calculated Langmuir monolayer adsorption capacity is 61.56 mg g-1 at pH of 2.0 and adsorption time of 120 min. Moreover, the mechanism studies by combining theoretical models with analytical spectroscopies reveal that the electrostatic attraction plays the important role to the uptake of Cr(VI) onto MnO2/CS nanocomposite. Therefore, the present nanocomposite material can be applied to remove total Cr from wastewater produced by the galvanized manufacturing factory with a relatively high efficiency.


Asunto(s)
Cromo/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adsorción , Quitosano , Concentración de Iones de Hidrógeno , Cinética , Compuestos de Manganeso , Nanocompuestos , Óxidos/análisis , Aguas Residuales/análisis , Agua/análisis
8.
J Food Sci ; 85(5): 1411-1417, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32249422

RESUMEN

Tiger frog (Rana tigrina) meat is extremely perishable. This study investigated the antimicrobial efficacy of chlorine dioxide (ClO2 ) on frog meat, optimized the formulation of a phosphate-based enhancement solution by response surface methodology (RSM), and determined the quality parameters (i.e., total aerobic counts [TAC], pH, drip loss, cooking loss, color measurements, shear force, total volatile basic nitrogen [TVB-N], and thiobarbituric acid-reactive substances [TBARS]) of refrigerated frog meat pretreated with ClO2 and the optimized blend of phosphates. Treatments of frog meat with 35 and 70 ppm ClO2 for 3, 5, and 10 min achieved a 0.7-, 0.9- and 0.9-, and 0.8-, 1.4- and 1.6-log CFU/g reduction of TAC, respectively, indicating the antimicrobial efficacy of ClO2 was concentration- and time-dependent with such that higher concentrations and/or longer exposure time achieved greater bacterial reductions. The concentrations of the phosphates, including sodium tripolyphosphate (STPP), sodium pyrophosphate (SPP), and sodium hexametaphosphate (SHMP), were optimized as the formula of 0.3% STPP and 0.45% SPP obtaining the highest water retention of the frog meat. After washed with 70 ppm ClO2 for 10 min and subsequently soaked with 0.3% STPP and 0.45% SPP for 30 min, the frog meat stored at 4 °C shown significantly (P < 0.05) lower TAC (<4.4 log CFU/g) and higher water holding capacity during the whole storage of 12 days, compared to the control. Results indicated that the two-step process may be applicable to slow down deterioration and maintain quality frog meat during refrigeration. PRACTICAL APPLICATION: This research provides a means to slow down deterioration, maintain quality frog meat, and improve stability during refrigeration. Refrigerated frog meat products, which are preferred by consumers with juicier and more tender texture compared to the frozen-thawed meat, could be developed by the frog industry based on the data from this study.


Asunto(s)
Compuestos de Cloro/análisis , Conservación de Alimentos/métodos , Conservantes de Alimentos/análisis , Carne/análisis , Óxidos/análisis , Fosfatos/análisis , Animales , Culinaria , Difosfatos/análisis , Conservación de Alimentos/instrumentación , Almacenamiento de Alimentos , Polifosfatos/análisis , Ranidae , Refrigeración , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Agua/análisis
9.
Artículo en Chino | MEDLINE | ID: mdl-32306700

RESUMEN

Objective: To establish the method for determination of tantalum and tantalum pentoxide in the air of workplace by inductively coupled plasma optical emission spectrometry (ICP-OES). Methods: The tantalum and tantalum pentoxide in the workplace air were collected by filter membrane and then digested by microwave digestion apparatus in the mixed solvents (HNO(3)∶HF=3∶1) ,diluted to 50 ml and detected by ICP- OES. Results: The linearity of tantalum was good at the range of 0.0~100.0 µg/ml with a correlation coefficient of 0.9997, the LOD and LOQ were 0.04 µg/ml and 0.14 µg/ml, respectively. The recovery was ranged from 83.1%-87.8%; the RSD of intra-and inter-batch precision were 0.2%-1.0% and 1.1%-2.4%, respectively. The recovery was ranged from 87.4%-93.3%; the RSD of intra-and inter-batch precision were 0.5%-1.5% and 1.3%- 1.8%, respectively. Conclusion: The determination method meet the requirement of analysis and apply to the determination of tantalum and tantalum pentoxide in the air of workplace.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Óxidos/análisis , Tantalio/análisis , Lugar de Trabajo , Análisis Espectral
10.
PLoS One ; 15(3): e0229794, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32134972

RESUMEN

In soil metal ecotoxicology research, dosing is usually performed with metal salts, followed by leaching to remove excess salinity. This process also removes some metals, affecting metal mixture ratios as different metals are removed by leaching at different rates. Consequently, alternative dosing methods must be considered for fixed ratio metal mixture research. In this study three different metal mixture dosing methods (nitrate, oxide and annealed metal dosing) were examined for metal concentrations and toxicity. In the nitrate metal dosing method leaching reduced total metal retention and was affected by soil pH and cation exchange capacity (CEC). Acidic soils 3.22 (pH 3.4, CEC 8 meq/100g) and WTRS (pH 4.6, CEC 16 meq/100g) lost more than 75 and 64% of their total metals to leaching respectively while Elora (6.7 pH, CEC 21 meq/100g) and KUBC (pH 5.6, CEC 28 meq/100g) with higher pH and CEC only lost 13.6% and 12.2% total metals respectively. Metal losses were highest for Ni, Zn and Co (46.0%, 63.7% and 48.4% metal loss respectively) whereas Pb and Cu (5.6% and 20.0% metal loss respectively) were mostly retained, affecting mixture ratios. Comparatively, oxide and annealed metal dosing which do not require leaching had higher total metal concentrations, closer to nominal doses and maintained better mixture ratios (percent of nominal concentrations for the oxide metal dosing were Pb = 109.9%, Cu = 84.6%, Ni = 101.9%, Zn = 82.3% and Co = 97.8% and for the annealed metal dosing were Pb = 81.7%, Cu = 80.3%, Ni = 100.5%, Zn = 89.2% and Co = 101.3%). Relative to their total metal concentrations, nitrate metal dosing (lowest metal concentrations) was the most toxic followed by metal oxides dosing while the annealed dosing method was generally non-toxic. Due to the lack of toxicity of the annealed metals and their higher dosing effort, metal oxides, are the most appropriate of the tested dosing methods, for fixed-ratio metal mixtures studies with soil invertebrates.


Asunto(s)
Metales Pesados/toxicidad , Óxidos/toxicidad , Contaminantes del Suelo/toxicidad , Suelo/química , Animales , Concentración de Iones de Hidrógeno , Invertebrados , Metales Pesados/análisis , Nitratos/análisis , Nitratos/toxicidad , Óxidos/análisis , Reproducción/efectos de los fármacos , Sales (Química)/análisis , Sales (Química)/toxicidad , Contaminantes del Suelo/análisis , Pruebas de Toxicidad/métodos
11.
J Mater Chem B ; 8(11): 2238-2249, 2020 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-32096816

RESUMEN

Incorporation of dual functions, i.e., sensing and adsorption, into one single organic-inorganic hybrid material for the detection and removal of toxic permanganate (MnO4-) ions is of great importance, representing a challenging and new task in the design and application of new functional materials. However, most of the reported materials display only one function as either sensing probes or adsorbents. In this work, a fluorescent cuboid mesoporous silica-based hybrid material (SiO2@SFNO) is first prepared by the covalent coupling of a new safranin O-based fluorophore (2,8-dimethyl-5-phenyl-3,7-bis(3-(3-(triethoxysilyl)propyl)ureido)phenazin-5-ium chloride) (SFNO) and newly-made cuboid mesoporous silica, which showed selective dual-functional activities towards MnO4- and green emission at 575 nm with a long-range excitation wavelength that is suitable for bio-imaging application. The design of this SiO2@SFNO material is based on the position of -NHCONH- groups, which are mainly responsible for the strong and selective coordination with MnO4-. SiO2@SFNO is responsive to MnO4- at parts per billion (67 ppb) level; it also displays high adsorption ability (292 mg g-1) to MnO4- in aqueous solutions. The fluorescence responses of MnO4-in vivo (limnodrilus claparedianus and zebrafish) demonstrate the possibility of further application in biology. Interestingly, this SiO2@SFNO material is also capable of monitoring trace amounts of Hg2+ and Cu2+ in living organisms, holding great potential in bio-related applications.


Asunto(s)
Colorantes Fluorescentes/química , Compuestos de Manganeso/análisis , Compuestos de Manganeso/aislamiento & purificación , Óxidos/análisis , Óxidos/aislamiento & purificación , Dióxido de Silicio/química , Adsorción , Animales , Cobre/análisis , Iones/análisis , Mercurio/análisis , Fenazinas/química , Porosidad , Relación Estructura-Actividad , Pez Cebra
12.
Ecotoxicol Environ Saf ; 191: 110162, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31935557

RESUMEN

It is essential and challenged to understand the atmospheric arsenic pollution because it is much more complicated than in water and top-soil. Herein the different behavior of arsenic species firstly were discovered within the ambient PM2.5 collected during daytime and nighttime, winter and summer. The diurnal variation of arsenic species in PMs is significantly correlated with the presence of metallic oxides, specifically, ferrous, titanium and zinc oxides, which might play a key role in the process of the photo-oxidation of As(III) to As(V) with the meteorological parameters and regional factors excluded. Subsequently, the photo conversion of arsenite was detected on metal-loaded glass-fiber filters under visible light. The photo-generated superoxide radical was found to be predominantly responsible for the oxidation of As(III). In order to reveal toxicity differences induced by oxidation As(III), HepG2 cells were exposed to various arsenic mixture solution. We found that the antioxidant enzyme activities suppressed with increasing the As(III)/As(V) ratio in total, followed by the accumulation of intracellular ROS level. The glucose consumption and glycogen content also displayed an obvious reduction in insulin-stimulated cells. Compared to the expression levels of IRS-1, AKT and GLUT4, GLUT2 might be more vulnerable to arsenic exposure and lead to the abnormalities of glucose metabolism in HepG2 cells. Taken together, these findings clarify that the health risk posed by inhalation exposure to As-pollution air might be alleviated owing to the photo-driven conversion in presence of metal oxides.


Asunto(s)
Contaminantes Atmosféricos/análisis , Arseniatos/análisis , Arsenitos/análisis , Glucosa/metabolismo , Luz , Metales Pesados/análisis , Material Particulado/análisis , Contaminantes Atmosféricos/efectos de la radiación , Contaminantes Atmosféricos/toxicidad , Arseniatos/efectos de la radiación , Arseniatos/toxicidad , Arsenitos/efectos de la radiación , Arsenitos/toxicidad , Células Hep G2 , Humanos , Exposición por Inhalación/análisis , Modelos Teóricos , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Óxidos/análisis , Material Particulado/efectos de la radiación , Material Particulado/toxicidad
13.
Environ Monit Assess ; 192(2): 124, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31960198

RESUMEN

Investigation on the behavior of elements in the soil is important both in exploration and environmental geochemistry studies. Rare earth elements (REEs) are the most useful among all trace elements. REE studies have shown that they have important applications in igneous, sedimentary, and metamorphic petrology. This work aims to investigate the relationship of these elements with one another and the behavior of the major oxides and trace elements with REEs. Soil samples were obtained from the alteration site possibly related to mineralization and were analyzed for major oxides, trace elements, and REEs. The relationships between the major oxide-trace element/heavy metal and REE were investigated by statistical methods, such as descriptive statistics, correlation coefficient, and principle component analysis. According to the correlation coefficient matrix, light REEs (LREEs) showed weak to moderate negative correlation with MgO and MnO and moderately positive correlation with SiO2 and K2O. No association was detected between the heavy REEs (HREEs) and the main oxides, but a strong positive correlation with LREEs was observed. For the trace elements, LREE showed a weak positive correlation with Ba and Sn and moderate to strong positive correlation with As, Hf, Nb, Rb, Ta, Th, U, W, and Zr. They also displayed weak to moderate correlation with Sc, Co, Zn, Ni, and V. HREE showed weak to moderate positive correlation with Ni, Cs, Ga, Hf, Th, Zr, As, and LREE. Although REEs exhibited no direct correlation with Au and Ag, they showed a good correlation with some trace elements that are related to hydrothermally altered products. This study showed that REEs can also be used in exploration and environmental geochemistry studies by exploiting the relationship between REEs and other trace/heavy metal elements.


Asunto(s)
Metales de Tierras Raras/análisis , Contaminantes del Suelo/análisis , Oligoelementos/análisis , Monitoreo del Ambiente/métodos , Metales Pesados/análisis , Compuestos Orgánicos , Óxidos/análisis , Dióxido de Silicio/análisis , Suelo
14.
J Chromatogr A ; 1617: 460832, 2020 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-31928771

RESUMEN

This paper demonstrated a simple and rapid approach for the determination of lead dioxide in minium using a headspace gas chromatographic (GC) technique. This new approach was based on the measurement of carbon dioxide from the redox reaction between lead dioxide and oxalic acid in a sealed headspace vial. The obtained results indicated that the new approach had good measurement accuracy (relative errors ≤8.71%) and precision (RSD ≤2.86%). Moreover, the limit of quantification (LOQ) and limit of detection (LOD) for this new approach were respectively 0.34% and 0.10%, and the recoveries ranged from 97.9 to 101.7%. The new approach is low-cost and reliable, which has potential for use in the analysis of lead dioxide in minium and related products.


Asunto(s)
Cromatografía de Gases/métodos , Plomo/análisis , Óxidos/análisis , Dióxido de Carbono/análisis , Plomo/química , Límite de Detección , Ácido Oxálico/química , Oxidación-Reducción , Óxidos/química
15.
Environ Sci Pollut Res Int ; 27(5): 5108-5121, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31845282

RESUMEN

A novel cellulose microcrystalline-manganese dioxide nanocomposite (CMC-NMO) was synthesized by the redox reaction between potassium permanganate and ethanol based on cellulose microcrystalline. The cellulose microcrystalline (CMC) as support providing growth sites for the manganese dioxide nanowhiskers produced by the redox reaction and its application for Pb(II) and Cd(II) removal from aqueous was investigated. The characterization of as-synthesized material was revealed by various spectroscopic and microscopic techniques. Infrared-transform infrared (FITR) indicates that the incorporation of manganese oxide to CMC does not change the initial structure of it. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) data show that the manganese dioxide nanowhiskers with a few nanometers are uniformly dispersed on the surface of cellulose. Kinetics experiments reveal that Pb(II) and Cd(II) adsorption on CMC-NMO is a fast process and pseudo-second-order model fits the adsorption better. The maximum adsorption capacities of Pb(II) and Cd(II) obtained from the Langmuir model are 290.8 mg/g and 67.4 mg/g, respectively. The mechanism is mainly attributed to surface complexation and electrostatic attraction by energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analysis. In addition, depth removal experiments show that the residual concentrations of Pb(II) and Cd(II) in natural water after adsorption are lower than 0.01 mg/L. The regeneration and cyclic utilizing studies indicate that CMC-NMO has good adsorption stability. Therefore, the results indicate that this material can be employed as a potential adsorbent for current serious Pb(II) and Cd(II) pollution caused by industrial emissions. Graphical abstract.


Asunto(s)
Cadmio/análisis , Plomo/análisis , Compuestos de Manganeso/análisis , Nanocompuestos , Óxidos/análisis , Contaminantes Químicos del Agua , Adsorción , Cadmio/química , Celulosa/química , Cinética , Plomo/química , Compuestos de Manganeso/química , Óxidos/química , Agua
16.
Environ Pollut ; 257: 113492, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31744683

RESUMEN

Jarosite and birnessite secondary minerals play a pivotal role in the mobility, transport and fate of trace elements in the environment, although geochemical interactions of these compounds with extremely toxic thallium (Tl) remain poorly known. In this study, we investigated the sorption behavior of Tl(I) onto synthetic jarosite and birnessite, two minerals commonly found in soils and sediments as well as in mining-impacted areas where harsh conditions are involved. To achieve this, sorption and desorption experiments were carried out under two different acidic conditions and various Tl(I) concentrations to mimic natural scenarios. In addition, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and inductively coupled plasma (ICP) analyses were conducted to determine the performance of both minerals for Tl(I) sequestration. Our results indicate that both phases can effectively remove aqueous Tl by different sorption mechanisms. Jarosite preferentially incorporates Tl(I) into the structure to form Tl(I)-jarosite and eventually the mineral dorallcharite (TlFe3(SO4)2(OH)6) as increasing amounts of Tl are employed. Birnessite, however, favorably uptakes Tl(I) through an irreversible surface adsorption mechanism, underlining the affinity of Tl for this mineral in the entire concentration range studied (0.5-5 mmol L-1). Lastly, the presence of Tl(I) in conditions where aqueous molar ratio Tl/Mn is ∼0.25 inhibits the formation of birnessite since oxidation of Tl(I) to Tl(III) followed by precipitation of avicennite (Tl2O3) take place. Thus, the present research may provide useful insights on the role of both jarosite and birnessite minerals in Tl environmental cycles.


Asunto(s)
Compuestos Férricos/análisis , Óxidos/análisis , Contaminantes del Suelo/análisis , Sulfatos/análisis , Talio/análisis , Ácidos , Adsorción , Minerales/química , Minería , Modelos Químicos , Suelo/química
17.
Environ Sci Pollut Res Int ; 27(1): 1167-1174, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31820254

RESUMEN

Transport and retention of nano PbO (nPbO) in quartz sand-alluvial soil mixture column and alluvial soil column were investigated. The dissolution kinetics of nano size lead chemicals in alluvial soil and nPbO in different soils were investigated through aging experiment and batch extraction experiment. nPbO was trapped mainly near the inlet of both quartz sand-alluvial soil mixture column and alluvial soil column. pH value (6, 7, and 8) and ion strength (1 and 10 mM CaCl2) did not have obvious effect on the retention of nPbO. nPbO, nPbSO4, and nPbCO3 experienced distinguishable dissolution in alluvial soil, but had similar dissolution trend. The dissolution kinetics of nPbO in alluvial soil and black soil were similar, increasing fast at 0-60 days and then slowing down. The dissolution of nPbO in red soil extracted by using HCl solution, CaCl2 solution and deionized water increased obviously from 90 to 180 days, differed from that by using EDTA extraction. The dissolution kinetics from three contaminated soils assessed by EDTA was similar. Overall, although nPbO had much weaker transport than Pb (II), dissolution would improve its mobility greatly.


Asunto(s)
Plomo/análisis , Óxidos/análisis , Contaminantes del Suelo/análisis , Contaminación Ambiental , Cinética , Plomo/química , Concentración Osmolar , Óxidos/química , Cuarzo , Suelo , Contaminantes del Suelo/química , Solubilidad
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 229: 117883, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31818641

RESUMEN

In this study, we have designed and synthesized two new organic receptors R1 and R2 based on malonohydrazide for the recognition of biologically important anions. The receptor R1 capable of colorimetric discrimination of maleate over fumarate ion, exhibit significant color change from pale yellow to wine red due to intermolecular hydrogen bond between the R1 and maleate ion, supported by 1HNMR titration, where the peak at δ12.0 ppm attributed to the NH proton experiences a downfield shift upon binding with maleate ion. Receptor R1, equipped with two electron-withdrawing NO2 moieties as the chromogenic signaling unit enhance the hydrogen bonding tendency and acidity, and thus when comparing with receptor R2, R1 displayed substantial higher redshift (∆λmax) of 148 nm, 143 nm, and 140 nm towards F-, AcO-, and maleate anion in the DMSO. In addition, the synthesized receptors R1 and R2 are able to detect F-, AcO-, and AsO2- ions as their sodium salts in an aqueous solution with visual color change. Receptor R1 exhibit electrochemical response towards F- and AcO- ions. The receptors R1 and R2 are successfully applied for quantitative detection of F- ion in the toothpaste solution in an aqueous medium. Additionally, R1 and R2 exhibit fluorescence enhancement towards F- and AcO- ions in the DMSO. As well, R1 and R2 demonstrate to be potentially useful colorimetric chemosensor for sensing maleate ion using the test strip. The theoretical calculation based on TD-DFT corroborates well with the experimental results of the receptors R1 and R2 with fluoride, acetate and maleate.


Asunto(s)
Acetatos/análisis , Colorimetría , Fluoruros/análisis , Fumaratos/análisis , Hidrazinas/química , Hidrazinas/síntesis química , Maleatos/análisis , Receptores Artificiales/química , Aniones , Color , Teoría Funcional de la Densidad , Dimetilsulfóxido/química , Cinética , Límite de Detección , Modelos Moleculares , Óxidos/análisis , Espectroscopía de Protones por Resonancia Magnética , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117412, 2020 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-31357051

RESUMEN

Molybdenum dichalcogenides MoX2 (X=S, Se) have been found to possess intrinsic peroxidase-like activity. However, molybdenum oxides (MoO2) as peroxidase mimetics have not been exploited yet. Herein, MoO2 nanoparticles were synthesized by a simple hydrothermal method and found to possess the peroxidase-like activity for the first time. MoO2 nanoparticles could catalyze the oxidation of 3,3',5,5'-tetrametylbenzidine (TMB) by H2O2 to produce a blue-color product (oxTMB). The catalytic property and mechanism were investigated by stead-state kinetics experiment and free radicals scavenging experiment, respectively. Acetylcholinesterase (AChE) could catalyze the hydrolysis of acetylthiocholine chloride (ATCh) into thiocholine (TCh), which could reduce oxTMB to decrease the absorbance in solution. In the presence of AChE inhibitor tacrine, the generation of TCh was inhibited and the absorbance was preserved. Based on these properties, a colorimetric assay method was developed for AChE inhibitor tacrine. This work not only broadens the application of the peroxidase mimetics, but also overcome the disadvantages of traditional methods such as expensive, complex and vulnerable to background interference for colorimetric assay of AChE inhibitor.


Asunto(s)
Inhibidores de la Colinesterasa/análisis , Colorimetría/métodos , Nanopartículas del Metal/química , Molibdeno/química , Óxidos/química , Tacrina/análisis , Inhibidores de la Colinesterasa/metabolismo , Cinética , Nanopartículas del Metal/análisis , Molibdeno/análisis , Molibdeno/metabolismo , Óxidos/análisis , Óxidos/metabolismo , Peroxidasas/metabolismo , Tacrina/metabolismo
20.
Environ Sci Pollut Res Int ; 27(3): 2482-2501, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31848947

RESUMEN

It is necessary to control the emissions of toluene, which is hazardous to both human health and the atmosphere environment and has been classified as a priority pollutant. Manganese oxide-based (Mn-based) catalysts have received increased attention due to their high catalytic performance, good physicochemical characteristic, availability in various crystal structures and morphologies, and being environmentally friendly and low cost. These catalysts can be classified into five categories, namely single manganese oxide, Mn-based composite oxides, Mn-based special oxides, supported Mn-based oxides, and Mn-based monoliths. This review focused on the recent progress on the five types of Mn-based catalysts for catalytic removal of toluene at low temperature and further systematically summarized the strategies improving catalysts, including improving synthetic methods, incorporating MnOx with other metal oxides, depositing Mn-based oxides on proper supports, and tuning the supports. Moreover, the effect of coexisting components, the reaction kinetics, and the oxidation mechanisms toward the removal of toluene were also discussed. Finally, the future research direction of this field was presented.


Asunto(s)
Compuestos de Manganeso/análisis , Óxidos/análisis , Tolueno , Catálisis , Compuestos de Manganeso/química , Oxidación-Reducción , Óxidos/química , Tolueno/análisis
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