RESUMEN
The present paper is focused on enhancing the production of biohydrogen (bioH2) from dairy cow manure (DCM) through dark fermentation (DF). Two enhancement production strategies have been tested: i) the combination of H2O2 with sonification as pretreatment and ii) the co-fermentation with cheese whey as co-substrate. Concerning the pretreatment, the best combination was investigated according to the response surface methodology (RSM) by varying H2O2 dosage between 0.0015 and 0.06 g/gTS and ultrasonic specific energy input (USEI) between 35.48 and 1419.36 J/gTS. The increase of carbohydrates concentration was used as target parameter. Results showed that the combination of 0.06 g/gTS of H2O2 with 1419.36 J/gTS of USEI maximized the concentration of carbohydrates. The optimized conditions were used to pretreat the substrate prior conducting DF tests. The use of pretreatment resulted in obtaining a cumulative bioH2 volume of 51.25 mL/L and enhanced the bioH2 production by 125% compared to the control test conducted using raw DCM. Moreover, the second strategy, i.e. co-fermentation with cheese whey (20% v/v) as co-substrate ended up to enhancing the DF performance as the bioH2 production reached a value of 334.90 mL/L with an increase of 1372% compared to the control DF test. To further improve the process, dark fermentation effluents (DFEs) were valorized via photo fermentation (PF), obtaining an additional hydrogen production aliquot.
Asunto(s)
Peróxido de Hidrógeno , Estiércol , Animales , Bovinos , Fermentación , Suero Lácteo , Proteína de Suero de Leche , Carbohidratos , HidrógenoRESUMEN
The cultivation of orange (Citrus×sinensis) and its transformation is a major industry in many countries in the world, it leads to the production of about 25-30Mt of orange peel waste (OPW) per year. Until now many options have been proposed for the management of OPW but although they are technically feasible, in many cases their economic/environmental sustainability is questionable. This paper analyse at lab scale the possibility of using OPW as a substrate for anaerobic digestion. Specific objectives are testing the possible codigestion with municipal biowaste, verifying the effect on methane production of increasingly high concentration of orange essential oil (EO, that is well known to have antioxidant properties that can slower or either inhibit biomass activity) and obtaining information on the behaviour of d-limonene, the main EO component, during anaerobic digestion. The results indicate that OPW can produce up to about 370LnCH4/kgVS in mesophilic conditions and up to about 300LnCH4/kgVS in thermophilic conditions. The presence of increasingly high concentrations of EO temporary inhibits methanogenesis, but according to the results of batch tests, methane production restarts while d-limonene is partially degraded through a pathway that requires its conversion into p-cymene as the main intermediate.
Asunto(s)
Biocombustibles , Reactores Biológicos , Metano/química , Aceites Volátiles/química , Eliminación de Residuos/métodos , Aguas del Alcantarillado/química , Volatilización , Anaerobiosis , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Biomasa , Citrus sinensis , Ciclohexenos/química , Cimenos , Frutas , Residuos de Alimentos , Limoneno , Monoterpenos/química , Aceites de Plantas/química , Terpenos/química , ResiduosRESUMEN
An interesting documentation, related with the campaign for the diffusion of the vaccine in Italy at the beginning of the nineteenth century, is available at the Museum Luigi Cattaneo of Anatomical Waxes of the University of Bologna. In this collection there are two wax models reproducing a cow-udder with pocks and two girl arms with the pocks of a "true" and "false" vaccine rash. The waxes were moulded under the direction of the leading physician Pietro Moscati, and overlap with the engravings of the chief treatise about the cow-pox and vaccine published by Luigi Sacco in 1809. The presence of the same models also in the Museums of the University of Pavia, and the available documentation about these waxes, demonstrate the educational purpose of the preparations. According to Sacco, they would be an effective tool directed to physicians and midwiwes for the learning and the knowledge of the outcomes of vaccination.
Asunto(s)
Modelos Anatómicos , Vacunas/historia , Animales , Bovinos , Viruela Vacuna/historia , Viruela Vacuna/patología , Documentación/historia , Historia del Siglo XIX , Humanos , ItaliaRESUMEN
The kinetics of gas phase reactions of the ion C5H5Fe(+) with oxygen (Me2CO, Me2O, MeOH, iso-propanol, H2O) and nitrogen (NH3, NH2Me, NHMe2, NMe3) donor ligands have been studied by ion trap mass spectrometry. While in the literature reactions of the ion Fe(+), with the same ligands, the principal reaction path involves fragmentation in almost all the reactions of the ion C5H5Fe(+), formation of adduct ions is the major reaction path. The reactivity of these two ions is briefly compared in the ion trap conditions. Kinetic data for the ion C5H5Fe(+) indicate that the reactions show a large range of efficiency and a linear correlation is found between the log of the reaction rate constants and the ionization energy of ligands with the same donor atom.