Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Valorization of calcium carbonate-based solid wastes for the removal of hydrogen sulfide from gas

Cette thèse explore la possibilité d'utiliser des déchets solides carbonatés issus du procédé Solvay de fabrication de carbonate de sodium (Na2CO3) comme réactifs pour le traitement de l'H2S à des concentrations trouvées typiquement dans des stations d'épuration des eaux usées. Dans un premier temps, la réactivité de deux résidus issus du procédé Solvay ont été évalués en termes d'efficacité d'abattement d'H2S dans un réacteur gaz-liquide-solide à l'échelle laboratoire (250 ml). Ce réacteur fonctionne en mode semi-continu (passage continu du gaz à travers un volume fixe de suspension). L'influence des paramètres opératoires comme la teneur en solide de la suspension, la concentration en H2S, la vitesse d'agitation et le volume de suspension a été examinée. Les processus cinétiques et physico-chimiques mis en jeu ont été identifiés et expliqués malgré le milieu réactionnel complexe. Dans un deuxième temps, l'étude du traitement d'H2S a été réalisée à l'échelle pilote sur un site industriel de Solvay en utilisant une colonne à bulles avec passettes (170 L) qui fonctionne également en mode semi-continu. Les résultats de l'étude paramétrique à l'échelle laboratoire ont été confirmés à l'échelle pilote. Finalement, la colonne a été évaluée avec un effluent gazeux réel issu d'une station d'épuration d'eaux usées à Graulhet (81) qui contient jusqu'à 200 ppmv d'H2S. En présence d'autres gaz comme le méthane (0,4 % vol.), le dioxyde de carbone (2,5 % vol.), le système s'est révélé efficace pour l'abattement sélectif d'H2S. Un abattement quasi-total (100 %) a pu être maintenu pendant au moins deux semaines avec un batch de la suspension à base de résidu. Cette étude démontre la compétitivité du procédé en termes d'efficacité et de coût pour le traitement d'H2S dans des conditions ambiantes. Les résultats obtenus démontrent également la possibilité de transposition du procédé à l'échelle industrielle.The purpose of this study to valorize solid wastes from the Solvay process for the production of sodium carbonate as reagents for the treatment of H2S in air at concentrations typically found in wastewater treatment plants (tens to hundreds of ppmv of H2S). Firstly, the reactivity of two residues was evaluated in a gas-liquid-solid reactor at laboratory scale (250 ml). This reactor operates semi-continuously (continuous passage of gas through a fixed volume of slurry). The influence of operating parameters including the solid content of the suspension, the concentration of H2S, the stirring speed and the volume of suspension was discussed. The kinetics, physicochemical processes as well as mechanism involved have been identified despite the complex reaction medium. Secondly, the H2S treatment was investigated at pilot scale using a bubble column with trays (170 L) which also operates in semi-continuous mode. The results of the parametric study obtained at laboratory scale were checked at pilot scale. Finally, the column was evaluated with a real gaseous effluent from a wastewater plant in Graulhet (Tarn, France) which contains up to 200 ppmv of H2S. In the presence of other gases as methane (0.4% vol.) and carbon dioxide (2.5% vol.), the system has proven to be effective for the selective elimination of H2S. A near total abatement (100%) was maintained for at least two weeks with only one batch of suspension. Stable and non-volatile sulfur compounds (sulfates, sulfites, thiosulfates) were formed as products of the process. This study demonstrates the competitiveness of the process in terms of cost-effectiveness for the treatment of H2S in ambient conditions. The results obtained also demonstrate the possibility of scaling-up the method to an industrial scale

Valorisation des résidus carbonatés industriels pour le traitement de sulfure d'hydrogène dans les effluents gazeux

The purpose of this study to valorize solid wastes from the Solvay process for the production of sodium carbonate as reagents for the treatment of H2S in air at concentrations typically found in wastewater treatment plants (tens to hundreds of ppmv of H2S). Firstly, the reactivity of two residues was evaluated in a gas-liquid-solid reactor at laboratory scale (250 ml). This reactor operates semi-continuously (continuous passage of gas through a fixed volume of slurry). The influence of operating parameters including the solid content of the suspension, the concentration of H2S, the stirring speed and the volume of suspension was discussed. The kinetics, physicochemical processes as well as mechanism involved have been identified despite the complex reaction medium. Secondly, the H2S treatment was investigated at pilot scale using a bubble column with trays (170 L) which also operates in semi-continuous mode. The results of the parametric study obtained at laboratory scale were checked at pilot scale. Finally, the column was evaluated with a real gaseous effluent from a wastewater plant in Graulhet (Tarn, France) which contains up to 200 ppmv of H2S. In the presence of other gases as methane (0.4% vol.) and carbon dioxide (2.5% vol.), the system has proven to be effective for the selective elimination of H2S. A near total abatement (100%) was maintained for at least two weeks with only one batch of suspension. Stable and non-volatile sulfur compounds (sulfates, sulfites, thiosulfates) were formed as products of the process. This study demonstrates the competitiveness of the process in terms of cost-effectiveness for the treatment of H2S in ambient conditions. The results obtained also demonstrate the possibility of scaling-up the method to an industrial scale.Cette thèse explore la possibilité d'utiliser des déchets solides carbonatés issus du procédé Solvay de fabrication de carbonate de sodium (Na2CO3) comme réactifs pour le traitement de l'H2S à des concentrations trouvées typiquement dans des stations d'épuration des eaux usées. Dans un premier temps, la réactivité de deux résidus issus du procédé Solvay ont été évalués en termes d'efficacité d'abattement d'H2S dans un réacteur gaz-liquide-solide à l'échelle laboratoire (250 ml). Ce réacteur fonctionne en mode semi-continu (passage continu du gaz à travers un volume fixe de suspension). L'influence des paramètres opératoires comme la teneur en solide de la suspension, la concentration en H2S, la vitesse d'agitation et le volume de suspension a été examinée. Les processus cinétiques et physico-chimiques mis en jeu ont été identifiés et expliqués malgré le milieu réactionnel complexe. Dans un deuxième temps, l'étude du traitement d'H2S a été réalisée à l'échelle pilote sur un site industriel de Solvay en utilisant une colonne à bulles avec passettes (170 L) qui fonctionne également en mode semi-continu. Les résultats de l'étude paramétrique à l'échelle laboratoire ont été confirmés à l'échelle pilote. Finalement, la colonne a été évaluée avec un effluent gazeux réel issu d'une station d'épuration d'eaux usées à Graulhet (81) qui contient jusqu'à 200 ppmv d'H2S. En présence d'autres gaz comme le méthane (0,4 % vol.), le dioxyde de carbone (2,5 % vol.), le système s'est révélé efficace pour l'abattement sélectif d'H2S. Un abattement quasi-total (100 %) a pu être maintenu pendant au moins deux semaines avec un batch de la suspension à base de résidu. Cette étude démontre la compétitivité du procédé en termes d'efficacité et de coût pour le traitement d'H2S dans des conditions ambiantes. Les résultats obtenus démontrent également la possibilité de transposition du procédé à l'échelle industrielle

Comparatif expérimental des méthodes de détermination du silicium total dans un biogaz et un biométhane.

International audienc

Etat des lieux et comparatif expérimental des méthodes de détermination du silicium total dans un biogaz et un biométhane

Rapport Etude RECORD n°15-0157/1

Characterization of chars from regular and supercritical water gasification

International audienc

Management of waste to energy plants: quantifying total silicon in biogas.

International audienc

Valorization of Calcium Carbonate-Based Solid Wastes for the Treatment of Hydrogen Sulfide from the Gas Phase

International audienceThis paper focuses on the valorization of calcium carbonate-based solid wastes for theremoval of hydrogen sulfide from gas phase. Two solid wastes taken from industrial sites for theproduction of sodium carbonate and sodium bicarbonate by the Solvay process® were analyzedby different physico-chemical methods. Calcium carbonate was found as the main component ofboth the solid wastes. Trace amounts of other elements such as Mg, Al, Fe, Si, Cl, Na etc. werealso present in these wastes. These solid wastes showed higher sorption activity for the removalof H2S, compared to a pure commercial calcium carbonate. The contact time was found as animportant parameter for the complete H2S uptake. The addition of well-dispersed iron-basedparticles could be carried out by the standard incipient wetness impregnation method. Sorbentcontaining 1 wt.% of spiked iron had the similar sorption behavior compared to a commercialactivated carbon, in terms of reactivity and reactivation possibility

Metal-doped apatitic calcium phosphates: preparation, characterization,and reactivity in the removal of hydrogen sulfide from gas phase

International audienceWith the expansion of human activities, there are more and more living areasadjacent to industrial and/or agricultural activities such as chemical processes, petroleumprocesses, paint finishing, food processing, livestock farming, composting plants etc. Badodor is part of several nuisances caused by industrial and/or agricultural activities. Hydrogensulfide (H2S) is a typical odorous molecule which causes foul odor at very low concentration.This molecule is formed in different industrial installations, in particular in coal combustion,and petrochemical refinery. The separation and/or transformation of H2S from gas phase toodorless products are important processes for sustainable development.In this paper, we communicate the preparation of new sorbents for the sorption of H2Sfrom a synthetic gas effluent. These sorbents consist in an inorganic phase (hydroxyapatite) ashost particles, and well-dispersed particles of a metal oxide as guest particles which are theactive phase for the removal of H2S. At room conditions, iron, lead and zinc doped calciumphosphates were found to be effective for the removal of H2S. The performance of thesorbents depends on preparation method and the nature of active phases. This opens newprospects for the treatment of H2S from gas phase

Surface properties of carbonaceous residues from pyrogasification for catalytic applications

National audienc