Search results for "fosfori"
showing 10 items of 43 documents
Degradazione termica di biomasse lignocellulosiche in acido fosforico
2013
La lignocellulosa è la più abbondante fonte rinnovabile per la produzione di bioetanolo. Sfortunatamente la produzione di biocarburanti liquidi da scarti lignocellulosici presenta molti inconvenienti a causa della compattezza e della complessità di questi materiali, caratteristiche che rendono molto più difficoltosa la loro degradazione enzimatica in zuccheri fermentabili rispetto ad altri biopolimeri come l’amido. Inoltre il costo della produzione di bioetanolo da biomasse lignocellulosiche è ancora molto alto rispetto a quello dei processi industriali che utilizzano come materiale di partenza l’amido. Obiettivo del presente studio è quello di testare su campioni di biomassa lignocellulosi…
ISOLAMENTO DI BATTERI DEGRADATORI DI ORGANOFOSFORICI DA SUOLI MEDITERRANEI
2011
I pesticidi organofosforici sono utilizzati per migliorare la produzione agricola e per il controllo dei parassiti. Nonostante i benefici effetti sull’agricoltura, i pesticidi danneggiano gli organismi viventi in quanto interferiscono con i processi metabolici e si diffondono nelle matrici ambientali, tra le quali il suolo, che rappresenta un’importante risorsa. Lo scopo del presente lavoro è stato quello di studiare la biodiversità di batteri degradatori di organofosforici, in suoli mediterranei, differenti per il tipo di coltura e le pratiche agronomiche. I batteri rappresentano infatti, un’utile strumento nella bonifica di aree contaminate. Dai suoli, sono stati isolati 47 ceppi, capaci …
High-precision mass measurements of 25Al and 30P at JYFLTRAP
2016
The masses of the astrophysically relevant nuclei 25Al and 30P have been measured with a Penning trap for the first time. The mass-excess values for 25Al ( $\Delta = -8915.962(63)$ keV) and 30P ( $\Delta = -20200.854(64)$ keV) obtained with the JYFLTRAP double Penning trap mass spectrometer are in good agreement with the Atomic Mass Evaluation 2012 values but $ \approx$ 5-10 times more precise. A high precision is required for calculating resonant proton-capture rates of astrophysically important reactions 25Al (p, $ \gamma$ )26Si and 30P(p, $ \gamma$ )31S . In this work, $ Q_{(p,\gamma)} = 5513.99(13)$ keV and $ Q_{(p,\gamma)} = 6130.64(24)$ keV were obtained for 25Al and 30P , respectivel…
Multi-laboratory experiment PME11 for the standardization of phosphoproteome analysis
2022
6 p.-2 fig.-2 tab.
Purification of recovered phosphoric acid by extracting aluminium with di-2-ethylhexyl phosphoric acid
2021
AbstractThe extraction of aluminium from dilute phosphoric acid with di-2-ethylhexyl phosphoric acid (DEHPA) was optimized using response surface methodology. The optimization was based on the experimental three-level central composite face-centred design (CCF) and was conducted on real-life samples. The three variables included were pH, extractant concentration and aqueous to organic phase ratio (AO). Under the optimized conditions (pH 2.5, 0.6 M DEHPA and AO ratio 1:2), extraction efficiency of 99% for aluminium in four extraction stages is achieved. The purified phosphoric acid solution can then be utilized by the fertilizing industry. Stripping tests for organic phase loaded with alumin…
α-Aminophosphonates, Phosphinates, and Phosphine Oxides as Extraction and Precipitation Agents for Rare Earth Metals, Thorium, and Uranium : A Review
2022
α-Aminophosphonates, -phosphinates, and -phosphine oxides are a group of organophosphorus compounds that were investigated as extraction agents for rare earth (RE) metals and actinoids for the first time in the 1960s. However, more systematic investigations of their extraction properties towards REs and actinoids were not started until the 2010s. Indeed, recent studies have shown that these α-amino-functionalized compounds can outperform the commercial organophosphorus extraction agents in RE separations. They have also proven to be very efficient extraction and precipitation agents for recovering Th and U from RE concentrates. These actinoids coexist with REs in some of the commercially im…
Density-functional tight-binding modeling of electromechanics of phosphorene
2018
Single-layer black phosphorus or phosphorene is a two-dimensional material made from a puckered honeycomb structure. It is a semiconductor with a tunable band gap and both its mechanical and electronic properties are highly asymmetric because of the puckering. Recently there has been numerous computational studies and some experimental works trying to bring deeper understanding about this relatively new 2D material. In this study we simulate phosphorene using computationally low-cost density functional tight-binding (DFTB) method to see how stretching, shearing and bending affect its electronic properties. The band structure analysis shows that there is a relation between shearing and bendi…
Degradazione di pesticidi organofosforici in matrici ambientali
2008
Matrici quali acqua, suolo ed aria sono costantemente soggette a forti pressioni antropiche. I pesticidi pur avendo apportato grandi benefici alle attività agricole influiscono negativamente sugli equilibri degli ecosistemi. Circa 85-90% dei principi attivi applicati in agricoltura non raggiunge gli organismi a cui sono destinati, ma viene disperso nell’ambiente. In tale contesto l’individuazione di microrganismi deputati alla loro degradazione diventa un importante mezzo per la salvaguardia ambientale e della salute umana. Lo scopo del presente lavoro è stato quello di isolare batteri del suolo capaci di degradare composti organofosforici, i quali rivestono una notevole importanza nelle pr…
RAVITA Technology : new innovation for combined phosphorus and nitrogen recovery
2018
Abstract Present phosphorus (P) recovery technologies mainly contain P recovery from sludge liquor or ash. These types of technologies are suitable for large wastewater treatment plants (WWTPs) with enhanced biological phosphorus removal (EBPR), digestion and/or incineration. In Finland and other Nordic countries, strict P discharge limits require chemical precipitation, thus EBPR alone is not sufficient. Ammonium recovery from wastewater, on the other hand, is not so often discussed. However, recovery from WWTP reject waters would decrease the energy demand of ammonium synthesis by Haber-Bosh technology and the energy demand of the WWTP's biological process. Helsinki Region Environmental S…
Temperature, phosphorus and species composition will all influence phytoplankton production and content of polyunsaturated fatty acids
2023
Temperature increases driven by climate change are expected to decrease the availability of polyunsaturated fatty acids in lakes worldwide. Nevertheless, a comprehensive understanding of the joint effects of lake trophic status, nutrient dynamics and warming on the availability of these biomolecules is lacking. Here, we conducted a laboratory experiment to study how warming (18–23°C) interacts with phosphorus (0.65–2.58 μM) to affect phytoplankton growth and their production of polyunsaturated fatty acids. We included 10 species belonging to the groups diatoms, golden algae, cyanobacteria, green algae, cryptophytes and dinoflagellates. Our results show that both temperature and phosphorus w…