925 resultados para ball mill


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In the Mediterranean area, olive mill wastewater (OMW) and grape pomace (GP) are among the major agro-industrial wastes produced. These two wastes have a high organic load and high phytotoxicity. Thus, their disposal in the environment can lead to negative effects. Second-generation biorefineries are dedicated to the valorization of biowaste by the production of goods from such residual biomasses. This approach can combine bioremediation approaches to the generation of noble molecules, biomaterials and energy. The main aim of this thesis work was to study the anaerobic digestion of OMW and GP under different operational conditions to produce volatile fatti acids (VFAs) (first stage aim) and CH4 (second stage aim). To this end, a packed-bed biofilm reactor (PBBR) was set up to perform the anaerobic acidogenic digestion of the liquid dephenolized stream of OMW (OMWdeph). In parallel, the solid stream of OMW (OMWsolid), previously separated in order to allow the solid phase extraction of polyphenols, was addressed to anaerobic methanogenic digestion to obtain CH4. The latter experiment was performed in 100ml Pyrex bottles which were maintained at different temperatures (55-45-37°C). Together with previous experiments, the anaerobic acidogenic digestion of fermented GP (GPfreshacid) and dephenolized and fermented GP (GPdephacid) was performed in 100ml Pyrex bottles to estimate the concentration of VFAs achievable from each aforementioned GPs. Finally, the same matrices of GP and not pre-treated GP (GPfresh) were digested under anaerobic methanogenic condition to produce CH4. Anaerobic acidogenic and methanogenic digestion processes of GPs lasted about 33 days. Instead, the anaerobic acidogenic and methanogenic digestion process of OMWs lasted about 121 and 60 days, respectively. Each experiment was periodically monitored by analysing volume and composition of produced biogas and VFA concentration. Results showed that VFAs were produced in higher concentrations in GP compared to OMWdeph. The overall concentration of VFAs from GPfreshacid was approximately 39.5 gCOD L-1, 29 gCOD L-1 from GPdephacid, and 8.7 gCOD L-1 from OMWdeph. Concerning the CH4 production, the OMWsolid reached a high biochemical methane potential (BMP) at a thermophilic temperature (55°) than at mesophlic ones (37-45°C). The value reached was about 358.7 mlCH4 gSVsub-1. In contrast, GPfresh got a high BMP but at a mesophilic temperature. The BMP was about 207.3 mlCH4 gSVsub-1, followed by GPfreshacid with about 192.6 mlCH4 gSVsub-1 and lastly GPdephacid with about 102.2 mlCH4 gSVsub-1. In summary, based on the gathered results, GP seems to be a better carbon source for acidogenic and methanogenic microrganism compared to OMW, because higher amount of VFAs and CH4 were produced in AD of GP than OMW. In addition to these products, polyphenols were extracted by means of a solid phase extraction (SPE) procedure by another research group, and VFAs were utilised for biopolymers production, in particular polyhydroxyalkanoates (PHAs), by the same research group in which I was involved.

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Extracellular enzymes that white-rot fungi secrete during lignin decay have been proposed as promising agents for oxidizing pollutants. We investigated the abilities of the white-rot fungi Punctularia strigosozonata, Irpex lacteus, Trichaptum biforme, Phlebia radiata, Trametes versicolor, and Pleurotus ostreatus to degrade Number 6 fuel oil in wood sawdust cultures. Our goals are to advise bioremediation efforts at a brownfield redevelopment site on the Blackstone River in Grafton, Massachusetts and to contribute to the understanding of decay mechanisms in white-rot fungi. All species tested degraded a C10 alkane. When cultivated for 6 months, Irpex lacteus, T. biforme, P. radiata, T. versicolor and P. ostreatus also degraded a C14 alkane and the polycyclic aromatic hydrocarbon phenanthrene. Gene expression analyses of P. strigosozonata indicate differential gene expression in the presence of Number 6 oil and on pine and aspen sawdust.

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Objective: Identification of the ventrointermediate thalamic nucleus (Vim) in modern 3T high-field MRI for image-based targeting in deep brain stimulation (DBS) is still challenging. To evaluate the usefulness and reliability of analyzing the connectivity with the cerebellum using Q-ball-calculation we performed a retrospective analysis. Method: 5 patients who underwent bilateral implantation of electrodes in the Vim for treatment of Essential Tremor between 2011 and 2012 received additional preoperative Q-ball imaging. Targeting was performed according to atlas coordinates and standard MRI. Additionally we performed a retrospective identification of the Vim by analyzing the connectivity of the thalamus with the dentate nucleus. The exact position of the active stimulation contact in the postoperative CT was correlated with the Vim as it was identified by Q-ball calculation. Results: Localization of the Vim by analysis of the connectivity between thalamus and cerebellum was successful in all 5 patients on both sides. The average position of the active contacts was 14.6 mm (SD 1.24) lateral, 5.37 mm (SD 0.094 posterior and 2.21 mm (SD 0.69) cranial of MC. The cranial portion of the dentato-rubro-thalamic tract was localized an average of 3.38 mm (SD 1.57) lateral and 1.5 mm (SD 1.22) posterior of the active contact. Conclusions: Connectivity analysis by Q-ball calculation provided direct visualization of the Vim in all cases. Our preliminary results suggest, that the target determined by connectivity analysis is valid and could possibly be used in addition to or even instead of atlas based targeting. Larger prospective calculations are needed to determine the robustness of this method in providing refined information useful for neurosurgical treatment of tremor.

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In 2010 the Nearctic leafhopper Penestragania apicalis (Osb.& Ball) was found for the first time in Europe. Altogether there are now 16 known localities in France, Switzerland, Germany and Austria indicating that the species is well established for a rather long period and more widespread in Europe and perhaps worldwide. As in North America it lives on honeylocust (Gleditsia triacanthos L.), overwinters in the egg stage and probably has one or two generations a year, with adults at least from late June until early October. It is yet unclear if it causes relevant damage to the host plant in Europe.