At the present time, hazardous waste management is a major problem, like the waste containing asbestos. The development of a process for eradicating all types of asbestos waste is a real challenge. ...In this study, several usefully analysis techniques (XRD, SEM–EDX, and TEM) have been used to determine what kind of asbestos is present in the waste (amphiboles and/or chrysotile). The chrysotile-containing wastes were treated with nitric acid solution (HNO
3
) leading to obtain pure silica and an acidic solution. Alkaline treatment using sodium hydroxide (NaOH) was also used in the case of waste-containing amphiboles. A basic solution of silica was then obtained. Finally a first valorization route was proposed with the precipitation of the ions dissolved in the acid solution and a second with the synthesis of a zeolite using the solid silica resulting from the acid treatment and the solution coming from the alkaline treatment of the amphiboles as sources of silicon. This paper describes the implementation of a complete process adapted to chemically dissolve each type of waste (according to their composition, density and fiber content) and to transform or recover all the by-products of the process.
Une lésion osseuse ostéolytique n’est pas toujours révélatrice d’une pathologie néoplasique.
Nous rapportons l’observation d’une femme de 82ans splénectomisée dont le bilan de douleurs sous-costales ...révélait une masse hépatique calcifiée et une lésion vertébrale ostéolytique de L5 attribuée à une localisation osseuse d’échinococcose alvéolaire. Ce diagnostic était basé sur l’aspect typique de la masse hépatique hétérogène associée à une sérologie positive pour l’échinococcose alvéolaire.
À notre connaissance, il s’agit du premier cas d’échinococcose alvéolaire chez un patient splénectomisé. Cet antécédent pourrait avoir constitué un facteur de dissémination du parasite.
Osteolytic lesions are not always related to malignancies.
We report an 82-year-old woman suffering from subcostal pain. The patient underwent a splenectomy 40 years previously. CT-scan and MRI highlighted a calcified hepatic lesion associated with an osteolytic lesion of the L5 vertebra. Osteolytic and hepatic lesions were attributed to an alveolar echinococcosis based on positive serological assays.
To our knowledge, this is the first report of an alveolar echinococcosis in a patient with splenectomy and secondary lesions. We suggest that the splenectomy could have promoted the parasite spreading to vertebra.
New re-use applications are needed to address the relatively large quantity of waste electronic products generated in the world. Cathode-ray tubes (CRTs) from computer monitors and TV sets are a ...large component of such waste. The three glass components of CRTs are the funnel, panel and neck, which are produced by various manufacturers and are now collected by asset-recovery centres. In this paper, we characterize waste funnel and panel glass from dismantled cathode-ray tubes with a view to assisting the development of new re-use applications. The heavy metal (lead, barium, and strontium) content of such glass represents an acute risk to the environment. Our results of the chemical composition for different kinds of waste CRT glass including black & white and color CRTs show that CRT glass from different producers have generally similar chemical compositions. In particular, the compositions of funnel and panel black & white CRT glass are similar, but are different to those of panel and funnel color CRT glass. We also measured the following specific properties of each type of CRT glass: density, glass transition temperature, and linear coefficient of thermal expansion. It was found that the coefficients of thermal expansion of CRT glass do not vary with their composition. In contrast, the measured densities and glass transition temperatures do vary with composition. On the basis of our experimental data and data found in the literature, we outline the main properties of several waste CRT glass currently in circulation. The aim of this study was to provide the data required to determine if this kind of waste could be entirely (or partially) re-used and to aid the search for promising methods of treatment.
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•Rimicaris exoculata have developed antioxidant defences to cope with a metal-rich habitat.•The depressurization of the test chamber every 12h did not affect the biomarkers ...response.•The proposed method seems useful to assess toxicity to contaminants in deep-sea species.
In light of deep-sea mining industry development, particularly interested in massive-sulphide deposits enriched in metals with high commercial value, efforts are increasing to better understand potential environmental impacts to local fauna. The aim of this study was to assess the natural background levels of biomarkers in the hydrothermal vent shrimp Rimicaris exoculata and their responses to copper exposure at in situ pressure (30MPa) as well as the effects of depressurization and pressurization of the high-pressure aquarium IPOCAMP. R. exoculata were collected from the chimney walls of the hydrothermal vent site TAG (Mid Atlantic Ridge) at 3630m depth during the BICOSE cruise in 2014. Tissue metal accumulation was quantified in different tissues (gills, hepatopancreas and muscle) and a battery of biomarkers was measured: metal exposure (metallothioneins), oxidative stress (catalase, superoxide dismutase, glutathione-S-transferase and glutathione peroxidase) and oxidative damage (lipid peroxidation). Data show a higher concentration of Cu in the hepatopancreas and a slight increase in the gills after incubations (for both exposed groups). Significant induction of metallothioneins was observed in the gills of shrimps exposed to 4μM of Cu compared to the control group. Moreover, activities of enzymes were detected for the in situ group, showing a background protection against metal toxicity. Results suggest that the proposed method, including a physiologically critical step of pressurizing and depressurizing the test chamber to enable the seawater exchange during exposure to contaminants, is not affecting metal accumulation and biomarkers response and may prove a useful method to assess toxicity of contaminants in deep-sea species.
Aims: The objective of the present work was to describe an aerobic, mesophilic and heterotrophic marine bacterium, designated HYD657, able to produce an exopolysaccharide (EPS). It was isolated from ...a East Pacific Rise deep‐sea hydrothermal vent polychaete annelid.
Methods and Results: This micro‐organism, on the basis of the phenotypical features and genotypic investigations, can be clearly assigned to the Alteromonas macleodii species and the name A. macleodii subsp. fijiensis biovar deepsane is proposed. Optimal growth occurs between 30 and 35°C, at pH between 6˙5 and 7˙5 and at ionic strengths between 20 and 40 g l−1 NaCl. The G + C content of DNA was 46˙5%. This bacterium excreted, under laboratory conditions, an EPS consisting of glucose, galactose, rhamnose, fucose and mannose as neutral sugars along with glucuronic and galacturonic acids and a diacidic hexose identified as a 3‐0‐(1 carboxyethyl)‐d‐glucuronic acid. Its average molecular mass was 1˙6 × 106 Da.
Conclusions: The bacterium HYD657, for which the name A. macleodii subsp. fijiensis biovar deepsane is proposed, produces an unusual EPS in specific medium.
Significance and Impact of the Study: Due to its interesting biological activities, applications have been found in cosmetics. Its probable contribution to the filamentous microbial mat in the Alvinella pompejana microenvironment can be also mentioned.
GaAsO4 crystals were grown by a hydrothermal epitaxial process. Microcrystalline GaAsO4 powder was first synthesized by hydrothermal methods by using GaAs as a starting material in a sulfuric acid ...solvent under oxidizing conditions. Experimental conditions were optimized and the yield of the nutrient synthesis reached 88%. GaAsO4 powder was then used as the nutrient for growing GaAsO4 single crystals by epitaxy on (21¯0) oriented GaPO4, AlPO4 and GaAsO4 plates. Crystal growth was performed in a horizontal PTFE-lined autoclave divided into two parts using sulfuric acid as the solvent under a slow heating gradient. Hydrothermal conditions were optimized in order to improve the crystal quality. The influence of the nature and orientation of the seeds on the growth rate was studied. From the solubility curve, the solute supply ΔS as a function of temperature during the growth process was calculated. Transparent crystals were obtained with ΔS between 0.002 and 0.009mol/L. Large crystals (3.9×1.8×1.4cm3) of gallium arsenate were obtained. These crystals were cut into (21¯0), (010) and (001) plates. Mapping using Raman spectroscopy was performed in order to study the growth recovery on the seed. GaAsO4 crystals were characterized by infrared spectroscopy in order to quantify the amount of OH groups in the crystal structure. A low value of the absorption coefficient α at 3300cm−1 was measured 0.067cm−1 indicating a good crystal quality. Optical measurements were performed on GaAsO4 crystals by UV–vis–NIR spectrophotometry. Gallium arsenate exhibits the highest value of birefringence in the α-quartz group with Δn=0.033. The transmission in the spectral region above 250nm yields a bandgap of 5.85eV. Piezoelectric properties were measured on resonators. An electromechanical coupling coefficient of 20% was measured which is the highest in the α-quartz group. A quality factor QF of 3.2×1010 was obtained on a Y-cut plate. The C66 elastic constant was found to be 20GPa.
•Large single crystals of GaAsO4 were grown by epitaxy under hydrothermal conditions.•The use of 1.6M H2SO4 as the solvent leads to high crystalline quality.•A very low –OH content in the crystals was measured by IR absorption at 3300cm−1.•An optical bandgap of Eg=5.85eV was measured for GaAsO4.•A high piezoelectric coupling coefficient (k=20%) was measured on a GaAsO4 resonator.
A giant 800-m-diameter pockmark named REGAB was discovered on the Gabon continental margin actively emitting methane at a water depth of 3200
m. The microbial diversity in sediments from four ...different assemblages of chemosynthetic organisms, Mytilidae, Vesicomyidae, Siboglinidae and a bacterial mat, was investigated using comparative 16S rRNA gene sequence analysis. Aggregates of anaerobic methanotrophic archaea (ANME-2) and bacteria of the
Desulfosarcina/Desulfococcus cluster were found in all four chemosynthetic habitats. Fluorescence in situ hybridization targeting the ANME-2/
Desulfosarcina/Desulfococcus aggregates showed their presence few centimeters (3–5
cm) below the surface of sediment. 16S rRNA gene sequences from all known marine ANME groups were detected in the pockmark sediments, as well as from both known bacterial partners. The archaeal diversity was limited to the ANME cluster for all investigated samples. The bacterial diversity included members of the
Proteobacteria, Bacilliales, Cytophaga/Flavobacteria,
Verrucomicrobia, JS1 and
Actinobacteria clusters. Bacterial 16S rRNA gene sequences related to those of known sulphide-oxidizing symbionts were recovered from tissues of several invertebrates including vesicomyid clams and siboglinid tubeworms of REGAB.
The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR) hydrothermal ecosystems. These shrimps harbour in their gill chambers an ...important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by aggregated nanoparticles of two-line ferrihydrite and include other minor elements as Si, Ca, Mg, S and P, probably present as silicates cations, sulphates or phosphates respectively that may contribute to stabilise the ferrihydrite form of iron oxides. TEM-observations on the bacteria have revealed their close interactions with these minerals. Abiotic and biotic precipitation could occur within the gill chamber of Rimicaris exoculata, suggesting the biologically-mediated formation of the iron oxide deposits. The difference of the bacterial density in the three-mineral crust layers could be correlated to the importance of the iron oxide concretions and suggest that the first mineral particles precipitates on the lower layer which could be considered as the most likely location of iron-oxidizing bacteria.
Foam glasses can be prepared from lead silicate glasses through reaction with a reducing agent such as TiN or SiC. The environmental impact and specific characteristics of the final product (e.g., ...density, porosity, and thermal and mechanical properties) depend on the reaction processes that occur during expansion. The mechanisms of foam glass formation are determined in this study from experimental results, which we also use to determine the structural differences between the bulk (lead silicate glass before treatment) and foam glass (after heating the lead silicate glass with a reducing agent). This paper also presents measurements of the variation of the concentration of the divalent cation Pb(II) in the vitreous network (which initially contains 2–5mol% PbO) during the expansion process. These results were obtained with various methods, including X-ray diffraction, differential scanning calorimetry, photoelectron spectroscopy, and scanning electron microscopy with energy dispersive spectrometry. Our results show that a small proportion (about 20%) of the initial Pb(II) in network modifying sites is reduced to Pb metal, and the remaining proportion is present in the vitreous network as Pb(II) with another particular environment. Increasing the amount of SiC or TiN results in increased reduction of Pb(II). The quantity of the reducing agent can be optimized with respect to the temperature, pressure, and reaction rate.
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