Search results for "METHANE"

Metabolism of n-Butyl Benzyl Phthalate in the Female Wistar Rat. Identification of New Metabolites

1999

International audience; n-Butyl benzyl phthalate (BBP), a plasticizer used in polyvinylchloride (PVC) and other polymers, has been orally administered to female Wistar rats with four doses (150, 475, 780 and 1500 mg/kg body weight/day) for 3 consecutive days. Metabolites recovered in urines were analysed by gas chromatography±mass spectrometry (GC±MS) after 24, 48 and 72 hours. Six metabolites were identi®ed. Mono-n-butyl phthalate (MBuP) and mono-n-benzyl phthalate (MBeP) represented respectively 29± 34% and 7±12 % of the total recovered metabolites. Hippuric acid, the main metabolite of benzoic acid, represented the second major metabolite (51±56%). Phthalic acid, benzoic acid and an o-ox…

Di-chlorido-[N-(N,N-di-methyl-carbamimido-yl)-N',N',4-tri-methyl-benzohydrazonamide]-platinum(II) nitro-methane hemisolvate.

2014

In the title compound, [PtCl2(C13H21N5)]·0.5CH3NO2, the PtIIatom is coordinated in a slightly distorted square-planar geometry by two Cl atoms and two N atoms of the bidentate ligand. The (1,3,5-triazapentadiene)PtIImetalla ring is slightly bent and does not conjugate with the aromatic ring. In the crystal, N—H...Cl hydrogen bonds link the complex molecules, forming chains along [001]. The nitromethane solvent molecule shows half-occupancy and is disordered over two sets of sites about an inversion centre.

cis,cis,cis-(Acetato-k2O,O´)bis[1,2-bis- (diphenylphosphanyl)ethane-k2P,P´]- ruthenium(II) 0.75-trifluoromethanesulfonate 0.25-chloride

2013

In the title Ru(II) carboxyl-ate compound, [Ru(C2H3O2)(C26H24P2)2](CF3O3S)0.75Cl0.25, the distorted tris-bidentate octa-hedral stereochemistry about the Ru(II) atom in the complex cation comprises four P-atom donors from two 1,2-bis-(diphenyl-phosphan-yl)ethane ligands [Ru-P = 2.2881 (13)-2.3791 (13) Å] and two O-atom donors from the acetate ligand [Ru-O = 2.191 (3) and 2.202 (3) Å]. The disordered counter-anions are located on the same site in the structure in a 3:1 ratio, the expanded formula comprising four complex cations, three trifluoro-methane-sulfonate anions and one chloride anion, with two such formula units in the unit cell.

Diaqua[5,10,15,20-tetrakis(4-chlorophenyl)porphyrinato-κ4N]iron(III) trifluoromethanesulfonate–4-hydroxy-3-methoxybenzaldehyde–water (1/1/2)

2014

In the title compound, [Fe(C44H24Cl4N4)(H2O)2](SO3CF3)·C8H8O3·2H2O, the FeIIIcation is chelated by the four N atoms of the deprotonated tetrakis(4-chlorotetraphenyl)porphyrin (TClPP) and further coordinated by two water molecules in a distorted octahedral geometry. In the crystal, the cations, anions, 4-hydroxy-3-methoxybenzaldehyde and water molecules of crystallization are linked by classical O—H...O hydrogen bonds and weak C—H...O and C—H...Cl hydrogen bonds into a three-dimensional supramolecular architecture. The crystal packing is further stabilized by weak C—H...π interactions involving pyrrole and benzene rings. π–π stacking between parallel benzene rings of adjacent 4-hydroxy-3-met…

Methane efflux from the soil and methanotrophic activity in volcanic-geothermal areas: Examples from Italy and Greece

2013

Uncontrolled methane emissions from a MSW landfill surface: Influence of landfill features and side slopes

2013

Sanitary landfills for Municipal Solid Waste (MSW) disposal have been identified as one of the most important anthropogenic sources of methane (CH4) emissions; in order to minimize its negative effects on the environment, landfill gas (LFG) recovery is a suitable tool to control CH4 emissions from a landfill site; further, the measurement of CH4 emissions can represent a good way to evaluate the effectiveness of LFG recovering systems. In general, LFG will escape through any faults in the landfill capping or in the LFG collection system. Indeed, some areas of the capping can be more permeable than others (e.g. portions of a side slope), especially when considering a temporarily capped zone …

Evaluation of methane emissions from Palermo municipal landfill: Comparison between field measurements and models

2010

Methane (CH(4)) diffuse emissions from Municipal Solid Waste (MSW) landfills represent one of the most important anthropogenic sources of greenhouse gas. CH(4) is produced by anaerobic biodegradation of organic matter in landfilled MSW and constitutes a major component of landfill gas (LFG). Gas recovery is a suitable method to effectively control CH(4) emissions from landfill sites and the quantification of CH(4) emissions represents a good tool to evaluate the effectiveness of a gas recovery system in reducing LFG emissions. In particular, LFG emissions can indirectly be evaluated from mass balance equations between LFG production, recovery and oxidation in the landfill, as well as by a d…

The impact of methanotrophic activity on methane emissions through the soils of geothermal areas

2013

Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the most important greenhouse gas after carbon dioxide. It has recently been established that geogenic gases contribute significantly to the natural CH4 flux to the atmosphere (Etiope et al., 2008). Volcanic/geothermal areas contribute to this flux, being the site of widespread diffuse degassing of endogenous gases (Chiodini et al., 2005). In such an environment soils are a source rather than a sink for atmospheric CH4 (Cardellini et al., 2003; Castaldi and Tedesco, 2005; D’Alessandro et al., 2009; 2011; 2013). Due to the fact that methane soil flux measurements are laboratory intensive, very fe…

Geochemistry and mineralogy of sediments and authigenic carbonates from the Malta Plateau, Strait of Sicily (Central Mediterranean): Relationships wi…

2010

Abstract A mud volcano field was recently discovered within the Malta Plateau in the Strait of Sicily (Central Mediterranean Sea). Box-core sediments and associated authigenic carbonates have been collected in water depths of 140–170 m from two distinctive sectors of the area, and analyzed for major, trace and rare earth elements, stable isotopes, and mineralogy. Relative homogeneity in the mineralogy and geochemistry of bulk sediments, and 210Pb activity distributions, argue against an active mud ejection activity. In the Malta Plateau western sector, the sediments show high concentrations of Fe, As, Sb, and Mo, exceeding the background values estimated for the Strait of Sicily. Active flu…

Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

2014

Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a−1 (t a−1). Laboratory incubation experiments with three top-soil samples from …