4,675 research outputs found
Delignification and enhanced gas release from soil containing Lignocellulose by treatment with bacterial lignin degraders
Aims
The aim of the study was to isolate bacterial lignin-degrading bacteria from municipal solid waste soil, and to investigate whether they could be used to delignify lignocellulose-containing soil, and enhance methane release.
Methods and Results
A set of 20 bacterial lignin degraders, including 11 new isolates from municipal solid waste soil, were tested for delignification and phenol release in soil containing 1% pine lignocellulose. A group of 7 strains were then tested for enhancement of gas release from soil containing 1% lignocellulose in small-scale column tests. Using an aerobic pre-treatment, aerobic strains such as Pseudomonas putida showed enhanced gas release from the treated sample, but four bacterial isolates showed 5-10 fold enhancement in gas release in an in situ experiment under microanaerobic conditions: Agrobacterium sp., Lysinibacillus sphaericus, Comamonas testosteroni, and Enterobacter sp..
Conclusions
The results show that facultative anaerobic bacterial lignin degraders found in landfill soil can be used for in situ delignification and enhanced gas release in soil containing lignocellulose.
Significance & impact of the study
The study demonstrates the feasibility of using an in situ bacterial treatment to enhance gas release and resource recovery from landfill soil containing lignocellulosic waste
Synthesis of 1,3-diynes via detelluration of bis(ethynyl)tellurides
The synthesis of symmetric conjugated diyne systems with electron-withdrawing or electron-donating substituents via a palladium-catalyzed detelluration of bis(arylethynyl)tellurides and bis(alkylethynyl)tellurides is described. This procedure is effected under atmospheric conditions in DMF using Pd(OAc)2 as a catalyst and AgOAc as an additive in the presence of triethylamine. This route offers efficient access to conjugated diyne systems in short reaction time. X-ray crystallographic structure and solid-state conformation of bis(p-tolylethynyl)telluride show a supramolecular chain aligned along the b axis, sustained by C-H...π interactions.Neste artigo é descrita a síntese de sistemas diínicos conjugados contendo substituintes elétronatratores e elétron-doadores via a deteluração catalizada por paládio de bis-(ariletinil)teluretos e bis-(alquiletinil)teluretos. Este procedimento foi realizado sob condições atmosféricas em DMF usando Pd(Oac)2 como catalisador e AgOAc como um aditivo na presença de trietilamina. Esta rota oferece acesso eficiente a sistemas diínicos conjugados em um curto período de tempo. A estrutura cristalográfica por difração de raios X do telureto de bis(p-toluiletinila) e a conformação no estado sólido mostram uma cadeia supramolecular alinhada ao longo do eixo b, sustentada por interações CH...π.FAPESPCNP
Copper catalyzed cross-coupling reactions of diaryl ditellurides with potassium aryltrifluoroborate salts
We present here results of the cross-coupling reaction of diaryl ditellurides with potassium aryltrifluoroborate salts using a catalytic amount of Cu(OAc)2 and bypiridine in DMSO/H2O under air atmosphere. This cross-coupling reaction is general and was performed with diaryl ditellurides and potassium aryltrifluoroborate salts bearing electron-withdrawing, electron-donating and neutral substituents, affording the corresponding unsymmetrical diaryl tellurides in good to excellent yields.Apresentamos aqui resultados das reações de acoplamento de diteluretos de diarila com sais de ariltrifluoroborato de potássio, usando quantidades catalíticas de Cu(OAc)2 e bipiridina, em uma mistura de DMSO/H2O, sob ar atmosférico. Estas reações de acoplamento são gerais e são realizadas com diteluretos de diarila e sais de ariltrifluoroborato de potássio contendo substituintes neutros, retiradores e doadores de elétrons, fornecendo os correspondentes teluretos de diarila não simétricos em rendimentos de bons a excelentes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (Grants 07/56659-0 and 07/59404-2
Sentinel-2 analysis of flooded areas: applied case study "La Safor wetland, Spain"
[EN] La Safor wetland is a representative coastal wetland in the Valencia Region (eastern Spain, Mediterranean Sea). This wetland is recognized at an international level as a Special Protection Area (SPAs) for birds and a Site of Community Importance (SCIs) (Habitats Directive, European Council Directive). The wetland is located on a detrital plain aquifer which in turn is fed by a karstic aquifer in the near limestone reliefs. The flooded surface is variable and depends on pluviometry among other factors. The objective of this study is to analyse the effects of the flooded surface on land uses by remote sensing and Airborne LiDAR data. Sentinel-2A images processed at level 1C were obtained from Copernicus. LiDAR data was used to detect the most vulnerable areas affected by floods. In the results, we analysed the impact of the maximum flooded surface on land uses. We propose several corrective actions on the drainage net based on our analysis. This methodology can be applied to other wetland areas of similar characteristics. The advantage is the high spatial resolution which makes the methodology suitable for small sized wetlands.Pena-Regueiro, J.; Sebastiá-Frasquet, M.; Aguilar-Maldonado, JA.; Estornell Cremades, J.; Sanchís Blay, JA.; Morell-Monzó, S.; Altur Grau, VJ. (2020). Sentinel-2 analysis of flooded areas: applied case study "La Safor wetland, Spain". WIT Transactions on Ecology and the Environment (Online). 242:63-70. https://doi.org/10.2495/WP200061S637024
Bis[(4-methylphenyl)ethynyl] telluride
The tellurium atom in the title bis-ethynyl telluride, Te(C9H7)2 or C18H14Te, is located on a crystallographic twofold axis, the C—Te—C angle being 92.23 (15)°. The dihedral angle between the rings is 87.27 (7)°. In the crystal structure, molecules are connected in chains parallel to the b axis and mediated by C—H⋯π interactions
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