Primary and secondary organic aerosols in PM_(2.5)were investigated over a one-year campaign at Zouk Mikael and Fiaa,Lebanon.The n-alkanes concentrations were quite similar at both sites(26-29 ng/m^(3))and mainly expl...Primary and secondary organic aerosols in PM_(2.5)were investigated over a one-year campaign at Zouk Mikael and Fiaa,Lebanon.The n-alkanes concentrations were quite similar at both sites(26-29 ng/m^(3))and mainly explained by anthropogenic emissions rather than natural ones.The concentrations of total Polycyclic Aromatic Hydrocarbons(PAHs)were nearly three times higher at Zouk Mikael(2.56 ng/m^(3))compared to Fiaa(0.95 ng/m^(3)),especially for indeno[1,2,3-c,d]pyrene linked to the presence of the power plant.A characteristic indeno[1,2,3-c,d]pyrene/(indeno[1,2,3-c,d]pyrene+benzo[g,h,i]perylene)ratio in the range0.8-1.0 was determined for heavy fuel oil combustion from the power plant.Fatty acids and hopanes were also investigated and were assigned to cooking activities and vehicular emissions respectively.Phthalates were identified for the first time in Lebanon with high concentrations at Zouk and Fiaa(106.88 and 97.68 ng/m^(3) respectively).Moreover,the biogenic secondary aerosols revealed higher concentrations in summer.The total terpene concentration varied between 131 ng/m^(3) at Zouk Mikael in winter to 469 ng/m3 at Fiaa in summer.Additionnally,the concentrations of the dicarboxylic acids especially for adipic and phthalic acids were more influenced by anthropogenic sources.The analysis of molecular markers and diagnostic ratios indicated that the sites were strongly affected by anthropogenic sources such as waste open burning,diesel private generators,cooking activities,road transport,power plant,and industrial emissions.Moreover,results showed different pattern during winter and summer seasons.Whereas,higher concentrations of biogenic markers were clearly encountered during the summer period.展开更多
Chromium-incorporated mesoporous silica materials （MCrS） have been successfully prepared in strong acidic media by assembly of preformed CrSI precursors with triblock copolymer of the Pluronic type （P123） by a two...Chromium-incorporated mesoporous silica materials （MCrS） have been successfully prepared in strong acidic media by assembly of preformed CrSI precursors with triblock copolymer of the Pluronic type （P123） by a two steps procedure. Various techniques including XRD, N2 adsorption, FT-IR spectroscopy, diffuse reflectance UV-vis （DRUV-vis） and EPR were employed for the materials characterization. MCrS materials have a hexagonal structure with uniform mesopores and contain Cr（V） and Cr（VI） under low and high Cr content and that the mesoporous walls contain the MFI structure building units.展开更多
This study aims to investigate the ability of an imidazolium biobased Zwitterionic Ionic Liquids(ZILs)in enhancing the phytoavailability of copper from garden(G)and vineyard(V)soils using the model plant ryegrass.Unco...This study aims to investigate the ability of an imidazolium biobased Zwitterionic Ionic Liquids(ZILs)in enhancing the phytoavailability of copper from garden(G)and vineyard(V)soils using the model plant ryegrass.Uncontaminated and artificially contaminated CuSO_(4) soils,unamended and ZIL-amended soil modalities were designed.The copper/ZIL molar ratio(1/4)introduced was rationally established based on molecular modeling and on the maximal copper concentration in artificially contaminated soil.Higher accumulation of copper in the shoots was detected for the uncontaminated and copper contaminated ZIL amended V soils(18.9 and 23.3 mg/kg,respectively)contrary to G soils together with a ZIL concentration of around 3%(W/W)detected by LC-MS analyses.These data evidenced a Cu-accumulation improvement of 38%and 66%compared to non-amended V soils(13.6 and 13.9 mg/kg respectively).ZIL would be mainly present under Cu(II)-ZIL_(4) complexes in the shoots.The impact on the chemical composition of shoot was also studied.The results show that depending on the soils modalitity,the presence of free copper and/or ZIL led to different chemical compositions in lignin and monomeric sugar contents.In the biorefinery context,performances of enzymatic hydrolysis of shoots were also related to the presence of both ZIL and copper under free or complex forms.Ecotoxicity assessment of the vineyard soil samples indicated that the quantity of copper and ZIL remaining in the soils had no significant toxicity.ZIL amendment in a copper-contaminated soil was demonstrated as being a promising way to promote the valorization of phytoremediation plants.展开更多
Nitrate from the application of nitrogen-based fertilizers in intensive agriculture is a notorious waste product, though it lacks cost-effective solutions for its removal from potential drinking water resources. Catal...Nitrate from the application of nitrogen-based fertilizers in intensive agriculture is a notorious waste product, though it lacks cost-effective solutions for its removal from potential drinking water resources. Catalytic reduction appears to be a promising technique for converting nitrates to benign nitrogen gas. Mesoporous silica SBA-15 is a frequently used catalyst support that has large surface areas and highly ordered nanopores. In this work, mesoporous silica SBA-15 bimetallic catalysts for nitrate reduction were investigated. The catalyst was optimized for the selection of promoter metal (Sn and Cu), noble metal (Pd and Pt) and loading ratios of these metals at different temperatures and reduction conditions. The catalysts prepared were characterized by FT-IR, N2 physisorption, XRD, SEM, and ICP. All catalysts showed the presence of cylindrical mesoporous channels and uniform pore structures that remained even after metals loading. In the presence of a CO<sub>2</sub> buffer, the catalysts 4Pd-1Cu/SBA-15 and 1Pt-1Cu/SBA-15 reduced at 100?C under H2 and 1Pd-1Cu/SBA-15 reduced at 200°C under H2 demonstrated very high nitrate conversion. Furthermore, the forementioned Pd catalysts had higher N2 selectivity (88% - 87%) compared to Pt catalyst (80%). Nitrate conversion by the 4Pd-1Cu/SBA-15 catalyst was significantly decreased to 81% in the absence of CO<sub>2</sub>.展开更多
A spectrofluorimetric method for the direct analysis of carbendazim [methyl 2-benzimidazole carbamate (MBC)] fungicide and its metabolite 2-aminobenzimidazole (2-AB) in natural waters is described. Very low limit of d...A spectrofluorimetric method for the direct analysis of carbendazim [methyl 2-benzimidazole carbamate (MBC)] fungicide and its metabolite 2-aminobenzimidazole (2-AB) in natural waters is described. Very low limit of detection (LOD) and limit of quantification (LOQ) values of 0.002 - 0.06 ng/mL and 0.006 - 0.2 ng/mL, respectively, were determined by spectrofluorimetric method with small relative standard deviation (RSD) values < 1%. This spectrofluorimetric method was applied to the determination of MBC and 2-AB residues in natural waters, with satisfactory recovery values of (88.5% - 119.2%).展开更多
基金funded by the Research Council and the Faculty of Sciences of Saint Joseph University of Beirut–LebanonThe“Unitéde Chimie Environnementale et Interactions sur le Vivant”(UCEIV-UR4492)participates in the CLIMIBIO project,which is financially supported by the Hauts-de-France Region Council,the French Ministry of Higher Education and Researchthe European Regional Development Funds。
文摘Primary and secondary organic aerosols in PM_(2.5)were investigated over a one-year campaign at Zouk Mikael and Fiaa,Lebanon.The n-alkanes concentrations were quite similar at both sites(26-29 ng/m^(3))and mainly explained by anthropogenic emissions rather than natural ones.The concentrations of total Polycyclic Aromatic Hydrocarbons(PAHs)were nearly three times higher at Zouk Mikael(2.56 ng/m^(3))compared to Fiaa(0.95 ng/m^(3)),especially for indeno[1,2,3-c,d]pyrene linked to the presence of the power plant.A characteristic indeno[1,2,3-c,d]pyrene/(indeno[1,2,3-c,d]pyrene+benzo[g,h,i]perylene)ratio in the range0.8-1.0 was determined for heavy fuel oil combustion from the power plant.Fatty acids and hopanes were also investigated and were assigned to cooking activities and vehicular emissions respectively.Phthalates were identified for the first time in Lebanon with high concentrations at Zouk and Fiaa(106.88 and 97.68 ng/m^(3) respectively).Moreover,the biogenic secondary aerosols revealed higher concentrations in summer.The total terpene concentration varied between 131 ng/m^(3) at Zouk Mikael in winter to 469 ng/m3 at Fiaa in summer.Additionnally,the concentrations of the dicarboxylic acids especially for adipic and phthalic acids were more influenced by anthropogenic sources.The analysis of molecular markers and diagnostic ratios indicated that the sites were strongly affected by anthropogenic sources such as waste open burning,diesel private generators,cooking activities,road transport,power plant,and industrial emissions.Moreover,results showed different pattern during winter and summer seasons.Whereas,higher concentrations of biogenic markers were clearly encountered during the summer period.
文摘Chromium-incorporated mesoporous silica materials （MCrS） have been successfully prepared in strong acidic media by assembly of preformed CrSI precursors with triblock copolymer of the Pluronic type （P123） by a two steps procedure. Various techniques including XRD, N2 adsorption, FT-IR spectroscopy, diffuse reflectance UV-vis （DRUV-vis） and EPR were employed for the materials characterization. MCrS materials have a hexagonal structure with uniform mesopores and contain Cr（V） and Cr（VI） under low and high Cr content and that the mesoporous walls contain the MFI structure building units.
文摘This study aims to investigate the ability of an imidazolium biobased Zwitterionic Ionic Liquids(ZILs)in enhancing the phytoavailability of copper from garden(G)and vineyard(V)soils using the model plant ryegrass.Uncontaminated and artificially contaminated CuSO_(4) soils,unamended and ZIL-amended soil modalities were designed.The copper/ZIL molar ratio(1/4)introduced was rationally established based on molecular modeling and on the maximal copper concentration in artificially contaminated soil.Higher accumulation of copper in the shoots was detected for the uncontaminated and copper contaminated ZIL amended V soils(18.9 and 23.3 mg/kg,respectively)contrary to G soils together with a ZIL concentration of around 3%(W/W)detected by LC-MS analyses.These data evidenced a Cu-accumulation improvement of 38%and 66%compared to non-amended V soils(13.6 and 13.9 mg/kg respectively).ZIL would be mainly present under Cu(II)-ZIL_(4) complexes in the shoots.The impact on the chemical composition of shoot was also studied.The results show that depending on the soils modalitity,the presence of free copper and/or ZIL led to different chemical compositions in lignin and monomeric sugar contents.In the biorefinery context,performances of enzymatic hydrolysis of shoots were also related to the presence of both ZIL and copper under free or complex forms.Ecotoxicity assessment of the vineyard soil samples indicated that the quantity of copper and ZIL remaining in the soils had no significant toxicity.ZIL amendment in a copper-contaminated soil was demonstrated as being a promising way to promote the valorization of phytoremediation plants.
文摘Nitrate from the application of nitrogen-based fertilizers in intensive agriculture is a notorious waste product, though it lacks cost-effective solutions for its removal from potential drinking water resources. Catalytic reduction appears to be a promising technique for converting nitrates to benign nitrogen gas. Mesoporous silica SBA-15 is a frequently used catalyst support that has large surface areas and highly ordered nanopores. In this work, mesoporous silica SBA-15 bimetallic catalysts for nitrate reduction were investigated. The catalyst was optimized for the selection of promoter metal (Sn and Cu), noble metal (Pd and Pt) and loading ratios of these metals at different temperatures and reduction conditions. The catalysts prepared were characterized by FT-IR, N2 physisorption, XRD, SEM, and ICP. All catalysts showed the presence of cylindrical mesoporous channels and uniform pore structures that remained even after metals loading. In the presence of a CO<sub>2</sub> buffer, the catalysts 4Pd-1Cu/SBA-15 and 1Pt-1Cu/SBA-15 reduced at 100?C under H2 and 1Pd-1Cu/SBA-15 reduced at 200°C under H2 demonstrated very high nitrate conversion. Furthermore, the forementioned Pd catalysts had higher N2 selectivity (88% - 87%) compared to Pt catalyst (80%). Nitrate conversion by the 4Pd-1Cu/SBA-15 catalyst was significantly decreased to 81% in the absence of CO<sub>2</sub>.
基金the Service of Cooperation and Cultural Action of the Embassy of France for financial support
文摘A spectrofluorimetric method for the direct analysis of carbendazim [methyl 2-benzimidazole carbamate (MBC)] fungicide and its metabolite 2-aminobenzimidazole (2-AB) in natural waters is described. Very low limit of detection (LOD) and limit of quantification (LOQ) values of 0.002 - 0.06 ng/mL and 0.006 - 0.2 ng/mL, respectively, were determined by spectrofluorimetric method with small relative standard deviation (RSD) values < 1%. This spectrofluorimetric method was applied to the determination of MBC and 2-AB residues in natural waters, with satisfactory recovery values of (88.5% - 119.2%).
