Search results for " Phosphorus"
showing 10 items of 76 documents
Lattice Opening upon Bulk Reductive Covalent Functionalization of Black Phosphorus
2019
The chemical bulk reductive covalent functionalization of thin-layer black phosphorus (BP) using BP intercalation compounds has been developed. Through effective reductive activation, covalent functionalization of the charged BP by reaction with organic alkyl halides is achieved. Functionalization was extensively demonstrated by means of several spectroscopic techniques and DFT calculations; the products showed higher functionalization degrees than those obtained by neutral routes.
Noncovalent Functionalization and Passivation of Black Phosphorus with Optimized Perylene Diimides for Hybrid Field Effect Transistors
2020
Amongst the different existing methods to passivate black phosphorus (BP) from environmental degradation, the noncovalent functionalization with perylene diimides (PDI) has been postulated as one of the most promising routes because it allows preserving its electronic properties. This work describes the noncovalent functionalization and outstanding environmental protection of BP with tailor made PDI having peri-amide aromatic side chains, which include phenyl and naphthyl groups, exhibiting a significantly increased molecule-BP interaction. These results are rationalized by density functional theory (DFT) calculations showing that the adsorption energies are mainly governed by van der Waals…
Few-layer Black Phosphorous Catalyzes Radical Additions to Alkenes Faster than Low-valence Metals
2020
Abstract The substitution of catalytic metals by p‐block main elements has a tremendous impact not only in the fundamentals but also in the economic and ecological fingerprint of organic reactions. Here we show that few‐layer black phosphorous (FL‐BP), a recently discovered and now readily available 2D material, catalyzes different radical additions to alkenes with an initial turnover frequency (TOF0) up to two orders of magnitude higher than representative state‐of‐the‐art metal complex catalysts at room temperature. The corresponding electron‐rich BP intercalation compound (BPIC) KP6 shows a nearly twice TOF0 increase with respect to FL‐BP. This increase in catalytic activity respect to t…
Determination of Aldicarb, Aldicarb Sulfoxide, and Aldicarb Sulfone in Oranges by Simple Gas–Liquid Chromatography with Nitrogen–Phosphorus Detection
1994
Abstract A reversed-phase liquid chromatographic method, using an acetonitrile–water gradient mobile phase, and a gas-liquid chromatographic method with nitrogen–phosphorus and flame photometric detection were compared for simultaneous and separate determinations of trace quantities of aldicarb and its metabolites aldicarb sulfone and aldicarb sulfoxide. One hundred gram samples of fortified oranges were extracted with water–acetone, water-acetonitrile, or water–methanol, and the extracts were partitioned with methylene chloride. Partitioning with other organic solvents such as chloroform, ethyl acetate, or methyl isobutyl ketone was also investigated. When performed under optimal condition…
Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems
2011
The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Rea…
Struvite precipitation assessment in anaerobic digestion processes
2008
Struvite precipitation causes important operational problems during the sludge treatment process, especially when EBPR sludge is treated. Predicting struvite formation is critical to be able to design process alternative that best minimises struvite precipitation. With this aim, phosphorus precipitation in an anaerobic digestion pilot plant was studied using experimental data and mass balance analysis. The results obtained showed significant phosphorus precipitation as struvite (58% of the fixed phosphorus) and a low precipitation of calcium phosphates (15%), forming mainly hydroxyapatite (HAP). The rest of the phosphorus fixed in the digester (27%) was attributed to adsorption processes on…
Biological nitrogen and phosphorus removal in membrane bioreactors: model development and parameter estimation
2012
Membrane bioreactors (MBR) are being increasingly used for wastewater treatment. Mathematical modeling of MBR systems plays a key role in order to better explain their characteristics. Several MBR models have been presented in the literature focusing on different aspects: biological models, models which include soluble microbial products (SMP), physical models able to describe the membrane fouling and integrated models which couple the SMP models with the physical models. However, only a few integrated models have been developed which take into account the relationships between membrane fouling and biological processes. With respect to biological phosphorus removal in MBR systems, due to th…
Etude par spectroscopies de RMN 23Na, 31P et 1H : effets de la teneur en sel (NaCl) dans des matrices alimentaires
2008
The reduction of salt (NaCl) content in food has become a matter of public health. However, the multiple functions of salt in food make the reduction of its content difficult. The aim of this work was to demonstrate the applicability of NMR innovative techniques in order to characterise the mobility of sodium ions (distinction between ‘free’ and ‘bound’ sodium), to bring a better understanding of the role of salt in the organisation of the food matrix (in particular phosphorous molecules in dairy systems) and to study impact of salt on the mobility of aroma compounds. In a first step, the 23Na NMR study of iota-carrageenan gels validated the quantification of total sodium (Single-Quantum, S…
Impacts of marine aquaculture at large spatial scales: evidences from n and p catchment loading and phytoplankton biomass
2011
International audience; While several studies point at off-shore aquaculture as a possible source of impacts on the local marine environment, very few have analysed its effects at large scales such as at the bay, gulf or basin levels. Similar analyses are hampered by the multiple sources of disturbance that may concomitantly affect a given area. The present paper addresses these issues taking the Gulf of Castellammare (Southern Tyrrhenian Sea) as an example. Nitrogen (N) and phosphorous (P) loads were calculated for the period 1970-2007, and compared to chlorophyll-a concentration as measured inside and outside the Gulf over the same period. Results indicate that N and P catchment loading h…
Influence of ferric iron dosing on aerobic granular sludge: granule formation, nutrient removal and microbial community
2021
BACKGROUND: Three lab-scale sequencing batch reactors were used to investigate the effects of Fe3+ on aerobic granular sludge (AGS) formation, nutrient removal, and microbial community. RESULTS: The addition of 6 and 12 mg Fe3+ L−1 could not shorten the granulation time. However, compared to the reactor without Fe3+ addition (average sludge volume index at 30 min (SVI30) 70.8 mL g−1; stable average particle size 548 μm), the addition of 12 mg Fe3+ L−1 helped improve the physical properties of AGS (average SVI30 57.0 mL g−1; stable average particle size 1067 μm). Furthermore, with 12 mg Fe3+ L−1 addition (Fe3+ to PO43−-P molar ratio = 1.33), effective removal of NH4+-N (≤0.5 mg L−1) and PO43…