Optical Response of CVD-Grown ML-WS2 Flakes on an Ultra-Dense Au NP Plasmonic Array

The combination of metallic nanostructures with two-dimensional transition metal dichalcogenides is an efficient way to make the optical properties of the latter more appealing for opto-electronic applications. In this work, we investigate the optical properties of monolayer WS2 flakes grown by chemical vapour deposition and transferred onto a densely-packed array of plasmonic Au nanoparticles (NPs). The optical response was measured as a function of the thickness of a dielectric spacer intercalated between the two materials and of the system temperature, in the 75–350 K range. We show that a weak interaction is established between WS2 and Au NPs, leading to temperature- and spacer-thickness-dependent coupling between the localized surface plasmon resonance of Au NPs and the WS2 exciton. We suggest that the closely-packed morphology of the plasmonic array promotes a high confinement of the electromagnetic field in regions inaccessible by the WS2 deposited on top. This allows the achievement of direct contact between WS2 and Au while preserving a strong connotation of the properties of the two materials also in the hybrid system

Paper pulp-based adsorbents for the removal of pharmaceuticals from wastewater: A novel approach towards diversification

In this work, two pulps, bleached (BP) and raw pulp (RP), derived from the paper production process, were used as precursors of non-activated and activated carbons (ACs). In the case of non-ACs, the production involved either pyrolysis or pyrolysis followed by acid washing. For ACs production, the pulps were impregnated with K2CO3 or H3PO4, and then pyrolysed and acid washed. After production, the materials were physically and chemically characterized. Then, batch adsorption tests on the removal of two pharmaceuticals (the anti-epileptic carbamazepine (CBZ) and the antibiotic sulfamethoxazole (SMX)) from ultra-pure water and from Waste Water Treatment Plant (WWTP) effluents were performed. In ultra-pure water, non-ACs were not able to adsorb CBZ or SMX while ACs showed good adsorption capacities. In WWTP effluents, although ACs satisfactorily adsorbed CBZ and SMX, they showed lower adsorption capacities for the latter. Tests with WWTP effluents revealed that the best adsorption capacities were achieved by carbons produced from BP and activated with H3PO4: 92±19mgg-1 for CBZ and 13.0±0.6mgg-1 for SMX. These results indicate the potential of paper pulps as precursors for ACs that can be applied in wastewater treatment.publishe

Effects of large river dam regulation on bacterioplankton community structure

16 pages, 5 figures, 3 tablesLarge rivers are commonly regulated by damming, yet the effects of such disruption on prokaryotic communities have seldom been studied. We describe the effects of the three large reservoirs of the Ebro River (NE Iberian Peninsula) on bacterioplankton assemblages by comparing several sites located before and after the impoundments on three occasions. We monitored the abundances of several bacterial phylotypes identified by rRNA gene probing, and those of two functional groups (picocyanobacteria and aerobic anoxygenic phototrophic bacteria-AAPs). Much greater numbers of particles colonized by bacteria were found in upstream waters than downstream sites. Picocyanobacteria were found in negligible numbers at most sites, whereas AAPs constituted up to 14% of total prokaryotes, but there was no clear effect of reservoirs on the spatial dynamics of these two groups. Instead, damming caused a pronounced decline in Betaproteobacteria, Gammaproteobacteria and Bacteroidetes from upstream to downstream sites, whereas Alphaproteobacteria and Actinobacteria significantly increased after the reservoirs. Redundancy analysis revealed that conductivity, temperature and dissolved inorganic nitrogen were the environmental predictors that best explained the observed variability in bacterial community composition. Our data show that impoundments exerted significant impacts on bacterial riverine assemblages and call attention to the unforeseen ecological consequences of river regulationThis study was funded by the Confederaci on Hidrogr afica del Ebro. Additional funds were provided by the project SCARCE (Consolider-Ingenio 2010, CSD2009-00065). We acknowledge the support of Concha Duran throughout the study, and the help from Elisabet Tornes and Carmen Guti errez in the field and laboratoryPeer reviewe

Conventional and microwave pyrolysis of a macroalgae waste from the Agar–Agar industry. Prospects for bio-fuel production

[EN] A comparative study of the pyrolysis of a macroalgae industrial solid waste (algae meal) in an electrical conventional furnace and in a microwave furnace has been carried out. It was found that the chars obtained from both pyrolyses are similar and show good properties for performing as a solid bio-fuel and as a precursor of activated carbon. Bio-oils from conventional pyrolysis have a greater number of phenolic, pyrrole and alkane compounds whereas benzene and pyridine compounds are more predominant in microwave pyrolysis with a major presence of light compounds. The bio-gas fraction from microwave pyrolysis presents a much higher syngas content (H2 + CO), and a lower CO2 and CH4 proportion than that obtained by conventional pyrolysis. Yields are similar for both treatments with a slightly higher gas yield in the case of microwave pyrolysis due to the fact that microwave heating favors heterogeneous reactions between the gases and the char.The financial support for this work was provided by the operating program FEDER of Principado de Asturias 2007–2013 under the Project PC10-40. The authors thank the industry for providing the macroalgae industrial residue used in this work.Peer reviewe

New process for producing methanol from coke oven gas by means of CO2 reforming. Comparison with conventional process

[EN] A novel method of producing methanol from coke oven gas (COG), involving the CO2 reforming of COG to obtain an appropriate syngas for the synthesis of methanol is proposed. This method is compared with a conventional process of methanol synthesis from natural gas, in terms of energy consumption, CO2 emissions, raw material exploitation and methanol purity. Whereas this new process requires the consumption of less energy, the conventional process allows a higher energy recovery. CO2 emissions are considerably lower with the new process, but the geographic situation of the plant plays a determinant role. From the point of view of raw material exploitation and methanol purity, the process proposed yields better results. These results suggest that methanol production from coke oven gas would be a more attractive alternative to conventional processes.JMB acknowledges the support received from the CSIC JAE Program. Financial support from the PCTI Asturias (Projects PEST08-03 and PEST08-21) is also acknowledged. The authors would also like to express their gratitude to Professor José R. Alvarez, of the Department of Chemical and Environmental Engineering at the University of Oviedo, for his help in setting up the Fortran program used in the membrane gas separation unit within Aspen Plus.Peer reviewe