91 research outputs found

    Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

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    Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method) and the high-speed self-reversal method (HSSR method). Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment

    Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

    Get PDF
    Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D 2 method) and the high-speed self-reversal method (HSSR method). Regarding the preliminary results obtained with synthetic solutions, the D 2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment

    Alternative approach to the standard, measurements and testing programme used to establish phosphorus fractionation in soils

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    ACLThe fractionation of phosphorus in 9 soils was established according to the standards, measurements and testing (SMT) programme. Five fractions were so defined and phosphorus was analysed by spectrophotometry. In parallel, the phosphorus extracted in each fraction was determined using graphite furnace atomic absorption spectrometry (GFAAS) after validation of this technique using certified reference materials. Phosphorus in soils was named total phosphorus, inorganic and organic phosphorus, apatite and non-apatite inorganic phosphorus, depending on extractants. The use of both analytical techniques revealed differences between the concentration of phosphorus in soluble extracts and highlighted the fact that spectrophotometry was a selective analytical technique. In view of the resourceand time-consuming of the SMT procedure and the results obtained in the present study, an alternative method was proposed to estimate the fractionation of phosphorus in soil in order to precise the potential effects of phosphorus on plant nutrition when plant biomass is produced as part of metal-contaminated soil management. (C) 2017 Elsevier B.V. All rights reserved

    Benefits of Ryegrass on Multicontaminated Soils Part 1: Effects of Fertilizers on Bioavailability and Accumulation of Metals

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    ACLEffects of three phosphorus fertilizers on the shoot biomass and on the accumulation of alkali, alkaline earth, and transition metals in the shoots and roots of ryegrass were studied with two contaminated garden soils. Phosphates were added in sustainable quantities in order to reduce the environmental availability of carcinogenic metals (e.g., Cd and Pb) and to enhance the bioavailability of alkali and alkaline earth metals as well as micronutrients needed by plants. Addition of Ca(H2PO4)2 was the most convenient way to (i) limit the concentration of Cd and Pb, (ii) keep constant the transfer of macro- and micronutrient from the soil to the ryegrass shoots, (iii) decrease the availability of metals, and (iv) increase the ratio values between potential Lewis acids and Cd or Pb in order to produce biosourced catalysis. For instance, the real phytoavailability was reduced by 27%–57% and 64.2%–94.8% for Cd and Pb, respectively. Interestingly, the real phytoavailability of Zn was the highest in the least contaminated soils. Even if soils were highly contaminated, no visual toxicity symptoms were recorded in the growing ryegrasses. This indicates that ryegrass is suitable for the revegetation of contaminated gardens. To promote the sustainable ryegrass production on contaminated soils for production of new organic fragrance and drugs in green processes according to REACH (Registration, Evaluation, Authorisation, and Restriction of Chemicals) regulation, two processes should be recommended: assisted phytostabilization of the elements, and then assisted phytoextraction by using chelators. View Full-Tex

    From the contaminated soils to the ecocatalysts: An original investigation

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    COMInternational audienceThe number of contaminated sites by metals and metalloids (As, Cd, Cu, Pb and Zn) was around 1 250,000 in Europe in 2016. Most of them are located in France, notably in Northern France where numerous habitants live due to the high past industrial activities (mining, metallurgical, inorganic and organic chemistry). Consequently, environmental and sanitary problems like degradation and perturbation of soil activities (loss of the biodiversity
), non-compliant agricultural commodity, production of contaminated vegetables, lead poisoning and different types of symptoms in relation with metal human exposure were highlighted. This explains why the management of these contaminated soils (agricultural, urban and forest) is a great concern in the Hauts-de-France region and particularly in the contaminated area affected by the dust emission of two former lead and zinc smelters.Physical and chemical techniques (soil removal, soil washing, electrokinetic
) are widely used to remediate contaminated soils. However, most of them are expensive and destructive (fauna and flora are highly impacted and the resulting soils are often non-productive).To avoid the dispersion of contaminated soil particles, to restore contaminated sites and ecosystems and to maintain an economic activity in this area, an environmental friendly management based on the concept of assisted-phytoremediation and assisted-phytoextraction was studied. From this approach, the first interest was to immobilise the carcinogenic metals (Cd, Pb) and the second was to increase non-carcinogenic metal uptake by plants in order to elaborate new heterogeneous catalysts (called ecocatalysts) from the plant biomass. These bio-sourced catalysts were used in organic synthesis to produce pharmaceuticals taking into account the green chemistry concept. It was highlighted that these new catalysts were reusable, increased the reaction yields while minimizing the production of waste

    Temperature Effects on Retention and Separation of PAHs in Reversed-Phase Liquid Chromatography Using Columns Packed with Fully Porous and Core-Shell Particles

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    Effects of temperature on the reversed-phase chromatographic behavior of PAHs were investigated on three columns. The first was the recent C18 column (250 mm × 4.6 mm) packed with 5 ”m core-shell particles while the others were more conventional C18 columns (250 mm × 4.6 mm) packed with fully porous particles. Among the 16 PAHs studied, special attention has been paid to two pairs of PAHs, fluorene/acenaphthene and chrysene/benzo[a]anthracene, which often present coeluting problems. Due to the low surface area of the core-shell particles, lowest retention time of each PAH was highlighted and effects of the temperature on the separation of PAHs were negligible in regard to those using columns packed with fully porous particles. For each PAH studied, it was demonstrated that peaks were symmetrical and may be considered as Gaussian peaks when the column packed with core-shell particle was employed. In the best condition, the separation of PAHs was conducted at 16°C under very low pressure values (670–950 psi = 46–65 bars). Depending on PAHs, the limit of detection ranged from 0.88 to 9.16 Όg L−1. Analysis of spiked acetonitrile samples with PAHs at 10 and 50 ”g L−1 and tap water at 10 ”g L−1 gave very good recoveries (94%–109.3%) and high precision (1.1%–3.5%)

    Core-shell Particles: A Way to Greening Liquid Chromatography in Environmental Applications

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    ACLBackground: Since the 1990s, technical developments and theoretical studies of columns packed with core-shell and sub-core-shell particles demonstrated improved efficiency separation, time reduction, solvent use than fully porous columns. Thanks to this chromatographic system, environmental pollutants are being analysed under green conditions. Objective: This paper presents theoretical aspects and a review of the main features of core-shell technology focusing essentially on environmental applications. Method: The main advantages of core-shell columns may be summarized as follows: i) reduction of the eddy dispersion A term; ii) homogeneity of the particle size distribution reducing the velocity bias; (iii) superior mass transfer kinetics; iv) better performance of the separation (faster and greater). Results: Systematic comparisons with fully porous particles undeniably highlighted the benefits of core-shell technology in the separation of a great number of pollutants and “micropollutants” of different molecular weights which surround us and have an impact on the ecosystem. Conclusion: Core-shell particles are emerging as green substrates for the analysis of chemical species problematic for environment. The environmental gain in terms of limitation of analysis time and solvent consumption has been demonstrated. The current manuscript proposes an update of the literature devoted to the use of core-shell particles in environmental applications. Future trends in the field and the expectations of the scientific community are also described since increasing attention is being paid to the detection of environmental pollutants
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