CWPO of bisphenol A with iron catalysts supported on microporous carbons from grape seeds activation

This accepted manuscript is available under a CC BY-NC-ND licence after the 24 months embargo periodThe catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA) with Fe catalysts supported on activated carbon from grape seeds (GS) has been studied. The GS were pyrolized (N2, 600 °C, 2 h) and subjected to activation upon partial gasification with air (400 °C, 2 h). Oxidized samples of the char and activated carbon were also obtained upon treatment with HNO3. The Fe catalysts were prepared by incipient wetness impregnation with ferric nitrate solution. They showed narrow microporosity, with surface area values ≈350–500 m2 g−1 and total iron contents between 2.8 and 4.2% wt. The CWPO experiments were carried out at 50–80 °C. The best catalyst allowed complete conversion of BPA (100 mg L−1) and a 60% TOC reduction in 3 h reaction time at 80 °C and the theoretical stoichiometric amount of H2O2 (530 mg L−1). The ecotoxicity of the effluent was negligible and the biodegradability was highly improved. In a long-term experiment (100 h), the catalyst suffered a loss of activity upon the early stages on stream (≈15 h), where about 20% of Fe was lost, followed by a highly stable behavior for the rest of the experimentThe authors wish to thank the Spanish MINECO and Comunidad de Madrid for the financial support through the projects CTM2013-43803-P and S2013/MAE-2716, respectively. I. F. Mena wishes to thank the MINECO and the ESF for a research gran

Sono- and photoelectrocatalytic processes for the removal of ionic liquids based on the 1-butyl-3-methylimidazolium cation

This Accepted Manuscript will be available for reuse under a CC BY-NC-ND license after 24 months of embargo periodIn this work, sono- and photoelectrolysis of synthetic wastewaters polluted with the ionic liquids 1-Butyl-3-methylimidazolium acetate (BmimAc)and chloride (BmimCl)were investigated with diamond anodes. The results were compared to those attained by enhancing bare electrolysis with irradiation by UV light or with the application of high-frequency ultrasound (US). Despite its complex heterocyclic structure, the Bmim+ cation was successfully depleted with the three technologies that were tested and was mainly transformed into four different organic intermediates, an inorganic nitrogen species and carbon dioxide. Regardless of the technology that was evaluated, removal of the heterocyclic ring is much less efficient (and much slower)than oxidation of the counter ion. In turn, the counter ion influences the rate of removal of the ionic liquid cation. Thus, the electrolysis and photoelectrolysis of BmimAc are much less efficient than sonoelectrolysis, but their differences become much less important in the case of BmimCl. In this later case, the most efficient technology is photoelectrolysis. This result is directly related to the generation of free radicals in the solution by irradiation of the electrochemical system with UV light, which contributes significantly to the removal of Bmim+The authors gratefully appreciate financial support from the Spanish MICINN (CTM2016-76197-R and CTM2016-76564-R, European Union (AEI/FEDER, UE) and Consejería de Educación of the CM (REMTAVARES S2013/MAE-2716). I. F. Mena wishes to thank the Spanish MINECO and the ESF for a research gran

Catalytic wet peroxide oxidation of imidazolium-based ionic liquids: Catalyst stability and biodegradability enhancement

This Accepted Manuscript will be available for reuse under a CC BY-NC-ND license after 24 months of embargo periodThe catalytic wet peroxide oxidation (CWPO) of the imidazolium-based ionic liquids 1-butyl-3-methylimidazolium chloride (BmimCl), 1-butyl-3-methylimidazolium acetate (BmimAc), 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BmimNTf2), 1-hexyl-3-methylimidazolium chloride (HmimCl) and 1-decyl-3-methylimidazolium chloride (DmimCl) was examined by using a Fe catalyst supported on alumina (Fe2O3/Al2O3) that was prepared by incipient wetness impregnation. Variable H2O2 doses from 0.5 to 1.5 times the stoichiometric value provided similar results in terms mg TOC removed per mg H2O2 decomposed at 80 °C (0.033 mgTOC mgH2O2−1), all allowing complete Bmim+ removal. Raising the reaction temperature to 90 °C increased the mineralization rate up to 40% TOC conversion. Differences in TOC conversion among counteranions (chloride, acetate and NTf2−) were negligible. A plausible reaction pathway is propose involving hydroxylated compounds and short-chain organic acids as reaction byproducts. CWPO markedly increased the subsequent biodegradability of the IL test solutions and led there to TOC conversions after CWPO-biodegradability assays of 55–60%. The Fe2O3/Al2O3 catalyst exhibited high long-term stability; thus, it retained most of its properties and underwent negligible Fe leaching.The authors acknowledge funding from Spain’s MINECO (CTM2016-76564-R), the Madrid Regional Government (S2013/MAE-2716), UAM-Santander (CEAL-AL/2015-08) and UNAM Engineering Institute (II-4307). I. F. Mena also thanks MINECO and ESF for award of a research gran

Towards the Electrochemical Retention of CO2: Is it Worth it?

Electrolyzer-absorber for CO2 capture: NaOH produced cathodically by reduction of water is able to retain gaseous CO2 in a combined electrolyzer-absorber device. The process deals with two relevant environmental concerns: desalination and carbon sequestering, with only electricity and heat, which can be provided using green sources. Results demonstrate that technology is feasible, obtaining removal rates of 130 mmol CO2/h at 7.5 A with coulombic efficiency in the removal of CO2 of 47.63 %.Electrolizador-absorbedor para captura de CO 2 : El NaOH producido catódicamente por reducción de agua es capaz de retener CO 2 gaseoso en un dispositivo combinado electrolizador-absorbedor. El proceso aborda dos preocupaciones ambientales relevantes: la desalinización y el secuestro de carbono, con solo electricidad y calor, que pueden proporcionarse utilizando fuentes verdes. Los resultados demuestran que la tecnología es factible, obteniendo tasas de remoción de 130 mmol CO 2 /ha 7.5 A con una eficiencia culómbica en la remoción de CO 2 de 47.63 %

Postharvest control of Rhizopus stolonifer on blackberry (Rubus fruticosus) by blackberry native crop bacteria

The potential of four native bacterial strains of blackberries cv. Brazos (Rubus fruticosus): Bacillus subtilis (BSS), Bacillus subtilis (BSL), Bacillus licheniformis (BLI) and Leifsonia aquatica (LAQ), was evaluated for the postharvest control of soft rot caused by Rhizopus stolonifer in blackberry fruits. The fruits were treated with cell suspensions (CS) and cell-free supernatants (CFE) from each bacterial strain and were infected with two strains of R. stolonifer (RSA and RSC). The severity and inhibition percentage of the disease were determined. Additionally, the inhibition by siderophores and the inhibition percentage of R. stolonifer spore germination were analyzed as possible control mechanisms. The CS of BSS inhibited RSA by 45.8%, followed by CFE of LAQ which controlled the same strain by 39.7%. The CS of BLI inhibited RSC by 37.7%, whereas the CFE of BSS and LAQ controlled it by 47.7 and 41.8%, respectively. All bacterial strains inhibited RSA and RSC by siderophores production (38.7 to 48.6 %) and the inhibition of spore germination of RSC was higher than 93% after 48 h. This work is one of the first to report R. stolonifer control by native bacteria CS and CFE, particularly LAQ in postharvested blackberry fruits. These results show the combination of mechanisms used by bacteria to control both R. stolonifer strains.The potential of four native bacterial strains of blackberries cv. Brazos (Rubus fruticosus): Bacillus subtilis (BSS), Bacillus subtilis (BSL), Bacillus licheniformis (BLI) and Leifsonia aquatica (LAQ), was evaluated for the postharvest control of soft rot caused by Rhizopus stolonifer in blackberry fruits. The fruits were treated with cell suspensions (CS) and cell-free supernatants (CFE) from each bacterial strain and were infected with two strains of R. stolonifer (RSA and RSC). The severity and inhibition percentage of the disease were determined. Additionally, the inhibition by siderophores and the inhibition percentage of R. stolonifer spore germination were analyzed as possible control mechanisms. The CS of BSS inhibited RSA by 45.8%, followed by CFE of LAQ which controlled the same strain by 39.7%. The CS of BLI inhibited RSC by 37.7%, whereas the CFE of BSS and LAQ controlled it by 47.7 and 41.8%, respectively. All bacterial strains inhibited RSA and RSC by siderophores production (38.7 to 48.6 %) and the inhibition of spore germination of RSC was higher than 93% after 48 h. This work is one of the first to report R. stolonifer control by native bacteria CS and CFE, particularly LAQ in postharvested blackberry fruits. These results show the combination of mechanisms used by bacteria to control both R. stolonifer strains

Evaluation of Goethite as a Catalyst for the Thermal Stage of the Westinghouse Process for Hydrogen Production

This work focuses on the evaluation of goethite as a catalyst for the transformation of sulfuric acid into sulfur dioxide, a reaction with great interest for the hybrid electrochemical-thermoelectrochemical Westinghouse cycle for hydrogen production. A comparison of the performance of goethite with that of CuO, Fe2O3, and SiC has been carried out. Moreover, a mixture of those catalysts was evaluated. The results demonstrate that goethite can be used as a catalyst for the thermal decomposition of sulfuric acid in the Westinghouse cycle, with an activity higher than that of SiC but lower than that of Fe2O3 and CuO. However, it does not undergo sintering during its use, but just produces small particles in its surface, which remain after the treatment. Mixtures of Fe2O3 with SiC or goethite do not produce synergism, thus operating each catalyst in an independent wayEste trabajo se centra en la evaluación de la goethita como catalizador para la transformación de ácido sulfúrico en dióxido de azufre, reacción de gran interés para el ciclo híbrido electroquímico-termoelectroquímico de Westinghouse para la producción de hidrógeno. Se ha llevado a cabo una comparación del rendimiento de la goethita con el de CuO, Fe 2 O 3 y SiC. Además, se evaluó una mezcla de esos catalizadores. Los resultados demuestran que la goetita se puede utilizar como catalizador para la descomposición térmica del ácido sulfúrico en el ciclo de Westinghouse, con una actividad superior a la del SiC pero inferior a la del Fe 2 O 3y CuO. Sin embargo, no sufre sinterización durante su uso, sino que solo produce pequeñas partículas en su superficie, que quedan después del tratamiento. Las mezclas de Fe 2 O 3 con SiC o goethita no producen sinergismo, por lo que cada catalizador opera de forma independient

Sono- and photoelectrocatalytic processes for the removal of ionic liquids based on the 1-butyl-3-methylimidazolium cation

In this work, sono- and photoelectrolysis of synthetic wastewaters polluted with the ionic liquids 1-Butyl-3-methylimidazolium acetate (BmimAc) and chloride (BmimCl) were investigated with diamond anodes. The results were compared to those attained by enhancing bare electrolysis with irradiation by UV light or with the application of high-frequency ultrasound (US). Despite its complex heterocyclic structure, the Bmim+ cation was successfully depleted with the three technologies that were tested and was mainly transformed into four different organic intermediates, an inorganic nitrogen species and carbon dioxide. Regardless of the technology that was evaluated, removal of the heterocyclic ring is much less efficient (and much slower) than oxidation of the counter ion. In turn, the counter ion influences the rate of removal of the ionic liquid cation. Thus, the electrolysis and photoelectrolysis of BmimAc are much less efficient than sonoelectrolysis, but their differences become much less important in the case of BmimCl. In this later case, the most efficient technology is photoelectrolysis. This result is directly related to the generation of free radicals in the solution by irradiation of the electrochemical system with UV light, which contributes significantly to the removal of Bmim+

Influence of the supporting electrolyte on the removal of ionic liquids by electrolysis with diamond anodes

In this work, it is studied the electrolysis with diamond anodes of three different ionic liquids (ILs): 1-butyl-3-methylimidazolium chloride (BmimCl), 1-hexyl-3-methylimidazolium chloride (HmimCl) and 1-decyl-3-methylimidazolium chloride (DmimCl), which differ only in the length of the aliphatic carbon chain attached to the imidazolium group. In addition, the effect of the presence of sulfate in the electrolyte is also evaluated. Results confirmed that this type of ILs can be completely transformed into carbon dioxide, nitrates, ammonium (the imidazolium cation) and perchlorate and chloramines (the chloride anion) during the electrolysis of the synthetic waste containing sulfate. The electrolysis of wastes without sulfate anions leads to a much less efficient process, with the same final products in the case of the BminCl and HminCl ILs and with the formation of a polymer as the main final product in the case of the DmimCl. These results are of a paramount significance from a mechanistic point of view since, because of the high conductivity of the ILs, there is not a necessity of salt addition and they inform about the pure removal of these compounds by electrolysis with BDD, pointing out the important influence of peroxodisulfate on the electrolyses with diamond of organic wastes

Does electro-peroxonation improve performance of electro-ozonation?

This work focuses on the comparison of the degradation and mineralization of clopyralid with electrochemically produced hydrogen peroxide (electro-H2O2), ozone (electro-ozonation) and their mixture (electro-peroxone) and points out important differences among the performance of the oxidation technologies. Co-existence of electrochemically produced hydrogen peroxide and ozone decreases the concentration of ozone and increases the concentration of hydrogen peroxide in the bulk, because of the formation and recombination of hydroxyl radicals. Oxidation of clopyralid and mineralization of the wastewater is less efficient with hydrogen peroxide and more efficient with ozone. Peroxone shows an intermediate performance which can be related with the oxidant’s speciation produced in the wastewater. Different behavior between in situ electrochemically produced ozone and ozone dosed, indicates activation of ozone in the electrolyte during the electro-ozonation process. Results highlights the good performance of the simple electro-ozonation that overcomes other EAOPs and indicates than combination of powerful oxidants in this case does not result in the expected synergism but in antagonistic responses.Este trabajo se centra en la comparación de la degradación y mineralización de la clopiralida con peróxido de hidrógeno producido electroquímicamente (electro-H 2 O 2 ), ozono (electro-ozonización) y su mezcla (electro-peroxona) y señala diferencias importantes entre el rendimiento de Las tecnologías de oxidación. La coexistencia de peróxido de hidrógeno y ozono producidos electroquímicamente disminuye la concentración de ozono y aumenta la concentración de peróxido de hidrógeno a granel, debido a la formación y recombinación de radicales hidroxilo.. La oxidación de clopiralida y la mineralización de las aguas residuales es menos eficiente con peróxido de hidrógeno y más eficiente con ozono. La peroxona muestra un comportamiento intermedio que se puede relacionar con la especiación del oxidante producido en las aguas residuales. El diferente comportamiento entre el ozono producido electroquímicamente in situ y el ozono dosificado, indica la activación del ozono en el electrolito durante el proceso de electro-ozonización. Los resultados destacan el buen desempeño de la electro-ozonización simple que supera a otros EAOP e indica que la combinación de potentes oxidantes en este caso no da como resultado el sinergismo esperado sino respuestas antagónicas

The Baryon Oscillation Spectroscopic Survey of SDSS-III

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A