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1.
Molecules ; 25(17)2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32825185

RESUMO

Polystyrene, despite its high flammability, is widely used as a thermal insulation material for buildings, for food packaging, in electrical and automotive industries, etc. A number of modification routes have been explored to improve the fire retardance and boost the thermal stability of commercially important styrene-based polymeric products. The earlier strategies mostly involved the use of halogenated fire retardants. Nowadays, these compounds are considered to be persistent pollutants that are hazardous to public and environmental health. Many well-known halogen-based fire retardants, regardless of their chemical structures and modes of action, have been withdrawn from built environments in the European Union, USA, and Canada. This had triggered a growing research interest in, and an industrial demand for, halogen-free alternatives, which not only will reduce the flammability but also address toxicity and bioaccumulation issues. Among the possible options, phosphorus-containing compounds have received greater attention due to their excellent fire-retarding efficiencies and environmentally friendly attributes. Numerous reports were also published on reactive and additive modifications of polystyrene in different forms, particularly in the last decade; hence, the current article aims to provide a critical review of these publications. The authors mainly intend to focus on the chemistries of phosphorous compounds, with the P atom being in different chemical environments, used either as reactive, or additive, fire retardants in styrene-based materials. The chemical pathways and possible mechanisms behind the fire retardance are discussed in this review.


Assuntos
Poluentes Ambientais/análise , Incêndios/prevenção & controle , Retardadores de Chama/análise , Compostos de Fósforo/análise , Polímeros/análise , Estireno/análise , Poluentes Ambientais/química , Compostos de Fósforo/química , Polímeros/química , Estireno/química
2.
Anal Bioanal Chem ; 410(7): 1911-1921, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29380018

RESUMO

Laser-ablation electrospray ionization (LAESI) imaging mass spectrometry (IMS) is an emerging bioanalytical tool for direct imaging and analysis of biological tissues. Performing ionization in an ambient environment, this technique requires little sample preparation and no additional matrix, and can be performed on natural, uneven surfaces. When combined with optical microscopy, the investigation of biological samples by LAESI allows for spatially resolved compositional analysis. We demonstrate here the applicability of LAESI-IMS for the chemical analysis of thin, desiccated biological samples, specifically Neotibicen pruinosus cicada wings. Positive-ion LAESI-IMS accurate ion-map data was acquired from several wing cells and superimposed onto optical images allowing for compositional comparisons across areas of the wing. Various putative chemical identifications were made indicating the presence of hydrocarbons, lipids/esters, amines/amides, and sulfonated/phosphorylated compounds. With the spatial resolution capability, surprising chemical distribution patterns were observed across the cicada wing, which may assist in correlating trends in surface properties with chemical distribution. Observed ions were either (1) equally dispersed across the wing, (2) more concentrated closer to the body of the insect (proximal end), or (3) more concentrated toward the tip of the wing (distal end). These findings demonstrate LAESI-IMS as a tool for the acquisition of spatially resolved chemical information from fragile, dried insect wings. This LAESI-IMS technique has important implications for the study of functional biomaterials, where understanding the correlation between chemical composition, physical structure, and biological function is critical. Graphical abstract Positive-ion laser-ablation electrospray ionization mass spectrometry coupled with optical imaging provides a powerful tool for the spatially resolved chemical analysis of cicada wings.


Assuntos
Hemípteros/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Asas de Animais/química , Amidas/análise , Aminas/análise , Animais , Ésteres/análise , Hemípteros/anatomia & histologia , Hidrocarbonetos/análise , Terapia a Laser , Lipídeos/análise , Compostos de Fósforo/análise , Sulfonas/análise
3.
Environ Monit Assess ; 188(6): 366, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27220505

RESUMO

The study of phosphorous dynamics in mangrove ecosystems of the northern Kerala coast aims to delineate its relationships with other biogeochemical parameters. Our intension is to check the validity of the hypothesis that these mangrove ecosystems act as an efficient trap of organic phosphorous by acting as P sink. The dissolved inorganic phosphate displayed higher concentration in monsoon that could be correlated with higher P leaching from mangrove litter as well as terrigenous input during wet season. Fe(OOH)≈P was much higher in monsoon (235.23 to 557.70 µg g(-1)) and lower in pre-monsoon (36.50 to 154.97 µg g(-1)), and displayed significant contribution towards the inorganic sedimentary P fractions. In monsoon, adsorption of P on iron hydroxides is enhanced by fresh water conditions, but pre-monsoon is characterised by the reductive dissolution of iron oxy hydroxides and the subsequent efflux of P to water column. CaCO3≈Pinorg may be present as an inert fraction in the sediment matrix, and did not display any interrelationship with other geochemical parameters. The abundant total organic P (25 to 73 %) fractions, largely derived from P bound with humic/fulvic acid, played a major role in immobilising P and regulating its dynamics in the nearby estuarine and coastal environment.


Assuntos
Sedimentos Geológicos/química , Compostos de Fósforo/química , Fósforo/química , Poluentes Químicos da Água/química , Áreas Alagadas , Ecossistema , Monitoramento Ambiental , Água Doce , Sedimentos Geológicos/análise , Índia , Ferro/química , Fósforo/análise , Compostos de Fósforo/análise , Estações do Ano , Poluentes Químicos da Água/análise
4.
Artigo em Inglês | MEDLINE | ID: mdl-25438132

RESUMO

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon were studied. The methodology considered a daily meteorological monitoring site. During 2011 to 2012, water, soil and plants (Schoenoplectus californicus (C.A. Méyer) Sójak, Typha angustifolia (L.)) were seasonally sampled (spring and fall) into the constructed wetland. During study period, results showed that rainfall was the main factor of maintenance hydraulic conditions, while evapotranspiration was driver of variations in water storage level. Nitrogen and phosphorus removal from the water phase were up to 54% and 37%, respectively. Onto soil were adsorbed over 70% nitrogen and 65% phosphorus. Phosphorus was less mobile than nitrogen, since it was bound to oxides Fe-Mn. Inorganic nitrogen species were affected by level water and seasonal vegetable maturation. During spring, N-NH4(+) was the predominant soil species, while in the fall, N-NO3(-) was dominant near the belowground part of Sc and NH4(+) near to the belowground zone of Ta. In addition, nutrients uptake was less than 30% with 64% aboveground-spring and 85% belowground-fall for both plants. Findings showed nitrification process evidences when water levels are below 0.1 m.


Assuntos
Compostos de Nitrogênio/análise , Compostos de Fósforo/análise , Suínos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Áreas Alagadas , Anaerobiose , Animais , Chile , Cyperaceae/crescimento & desenvolvimento , Esterco/microbiologia , Compostos de Nitrogênio/isolamento & purificação , Compostos de Fósforo/isolamento & purificação , Estações do Ano , Typhaceae/crescimento & desenvolvimento , Poluentes Químicos da Água/isolamento & purificação
5.
Eur J Mass Spectrom (Chichester) ; 20(2): 177-83, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24895778

RESUMO

Gas-phase ion-molecule reactions of four boron-containing neutrals were explored as a means for differentiation between isobaric phospho- and sulfocarbohydrates. Phosphorylation and sulfation impose an addition of 80 Da to the molecular mass, so for low-resolution mass spectrometers compounds that have such modifications will appear at the same nominal mass-to-charge (m/z) ratio. However, the ions of these isobaric species behave differently in ion-molecule reactions. All four evaluated neutral molecules [trimethyl borate (TMB), triethyl borate (TEB), diethylmethoxyborane (DEMB) and diisopropoxymethylborane (DIPMB)] proved to be reactive towards phosphorylated sugars and unreactive towards sulfated carbohydrates. In addition, TMB and TEB were found suitable for distinguishing positional isomers of phosphorylated carbohydrates, while reactions with DEMB and DIPMB were successful in differentiating phosphorylated, sulfated and unmodified deprotonated sugars. Similar reactions in the positive ion mode (alkali cationised) were found to be less conclusive.


Assuntos
Carboidratos/química , Gases/química , Íons/química , Compostos de Fósforo/química , Compostos de Enxofre/química , Carboidratos/análise , Transição de Fase , Compostos de Fósforo/análise , Espectrometria de Massas por Ionização por Electrospray , Compostos de Enxofre/análise
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(11): 3162-5, 2014 Nov.
Artigo em Zh | MEDLINE | ID: mdl-25752079

RESUMO

In order to better understand phosphorus (P) cycle in wetland ecosystem, the characteristics of phosphorus fractions in sediments of Heituwa constructed wetland system were investigated using soil organic phosphorus (Po) fractionation scheme and 31P-NMR technology. The concentrations of TP, Pi, Po and soil organic matter were all increased along the flow direction. Four kinds of P-compounds (orthophosphate, orthophosphate monoesters, orthophosphate diesters, and pyrophosphate) were detected in the NMR spectrum. Orthophosphate and phosphate monoester accounted for the dominants position in sediment phosphorus. This study indicates that the Po in sediment plays an importance role in wetland ecosystem and suggested that more attention should be paid to Po, especially to DNA-P and pyrophosphate in further research and management of constructed wetlands. Compared with the traditional chemical analysis method, 31P-NMR method has sample preparation relatively simple and is less destructive, with components analyzed completely. Using 31P-NMR technology, the cognition of wetland phosphorus cycle, especially organophosphate, will be expected to get new breakthrough.


Assuntos
Sedimentos Geológicos/química , Fósforo/análise , Áreas Alagadas , Espectroscopia de Ressonância Magnética , Compostos de Fósforo/análise , Solo/química
7.
Magn Reson Med ; 69(5): 1233-44, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22714782

RESUMO

A fully adiabatic phosphorus (31P) two-dimensional (2D) chemical shift spectroscopic imaging sequence with reduced chemical shift displacement error for 7 T, based on 1D-image-selected in vivo spectroscopy, combined with 2D-chemical shift spectroscopic imaging selection, was developed. Slice-selective excitation was achieved by a spatially selective broadband GOIA-W(16,4) inversion pulse with an interleaved subtraction scheme before nonselective adiabatic excitation, and followed by 2D phase encoding. The use of GOIA-W(16,4) pulses (bandwidth 4.3-21.6 kHz for 10-50 mm slices) reduced the chemical shift displacement error in the slice direction ∼1.5-7.7 fold, compared to conventional 2D-chemical shift spectroscopic imaging with Sinc3 selective pulses (2.8 kHz). This reduction was experimentally demonstrated with measurements of an MR spectroscopy localization phantom and with experimental evaluation of pulse profiles. In vivo experiments in clinically acceptable measurement times were demonstrated in the calf muscle (nominal voxel volume, 5.65 ml in 6 min 53 s), brain (10 ml, 6 min 32 s), and liver (8.33 ml, 8 min 14 s) of healthy volunteers at 7 T. High reproducibility was found in the calf muscle at 7 T. In combination with adiabatic excitation, this sequence is insensitive to the B1 inhomogeneities associated with surface coils. This sequence, which is termed GOIA-1D-ISIS/2D-CSI (goISICS), has the potential to be applied in both clinical research and in the clinical routine.


Assuntos
Algoritmos , Espectroscopia de Ressonância Magnética/métodos , Compostos de Fósforo/metabolismo , Adulto , Feminino , Humanos , Masculino , Especificidade de Órgãos , Compostos de Fósforo/análise , Isótopos de Fósforo/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
Water Sci Technol ; 68(1): 234-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23823560

RESUMO

The study was conducted on Dlugie Lake (area 26.8 ha, maximum depth 17.3 m), located in the town of Olsztyn, in north-eastern Poland (the Masurian Lake District). For 20 years starting in the 1950s, Dlugie Lake was used as a receiver of raw domestic and storm sewage in quantities oscillating between 350 and 400 m(3) day(-1). This led to complete degradation of the lake, known as saprotrophy. After some preliminary protective treatments in the catchment, the lake has been renewed by artificial aeration with thermal destratification and the phosphorus inactivation methods. Long-term reclamation of the reservoir has resulted in distinct and durable improvement of water quality. Before the restoration, the average phosphorus concentration in the surface water layer was 0.079 mg P L(-1) and in the over-bottom water it reached 2.277 mg P L(-1). The total phosphorus (TP) level also was very high, i.e. up to 3.5 mg P L(-1). After the restoration, these values have declined to 0.001-0.017 mg P L(-1) in the case of mineral P, and the current TP concentrations do not exceed 0.350 mg P L(-1).


Assuntos
Monitoramento Ambiental/métodos , Lagos/análise , Compostos de Fósforo/análise , Polônia , Poluentes Químicos da Água/análise
9.
Magn Reson Med ; 68(2): 339-48, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22213214

RESUMO

This study presents quantified levels of phosphorylated metabolites in glandular tissue of human breast using (31)P magnetic resonance spectroscopy at 7 T. We used a homebuilt (1)H/(31)P radiofrequency coil to obtain artifact-free (31)P MR spectra of glandular tissue of healthy females by deploying whole breast free induction decay (FID) detection with adiabatic excitation and outer volume suppression. Using progressive saturation, the estimated apparent T(1) relaxation time of (31)P spins of phosphocholine and phosphoethanolamine was 4.4 and 5.7 s, respectively. Quantitative measures for phosphocholine and phosphoethanolamine levels in glandular tissue were established based on MR imaging. We used a 3D (1)H image of the breast to segment the glandular tissue; this was matched to a 3D (31)P image of the B1- field of the (31)P coil to correct for differences in glandular tissue volume and B(1) inhomogeneity of the (31)P coil. The (31)P MR spectra were calibrated using a phantom with known concentration. Average levels of phosphocholine and phosphoethanolamine in 11 volunteers were 0.84 ± 0.21 mM and 1.18 ± 0.41 mM, respectively. In addition, data of three patients with breast cancer showed higher levels of phosphocholine and phosphoethanolamine compared with healthy volunteers. This may indicate a potential role for the use of (31)P magnetic resonance spectroscopy for characterization, prognosis, and treatment monitoring in breast cancer.


Assuntos
Algoritmos , Neoplasias da Mama/química , Mama/química , Espectroscopia de Ressonância Magnética/métodos , Compostos de Fósforo/análise , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Isótopos de Fósforo/análise
10.
Magn Reson Med ; 68(2): 332-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22190173

RESUMO

In application of the (31)P selectively refocused insensitive nuclei enhanced polarization transfer (srINEPT) technique to the detection of phosphomono- and diesters in tissues, homonuclear couplings between the CH(2)O protons and the NCH(2) protons seriously attenuate the sensitivity. These couplings can be conventionally removed by two soft 180° pulses in the (1)H evolution period which selectively invert the NCH(2) magnetizations. However, the srINEPT pulse sequence can be simplified by replacing the pulse train "soft 180°-hard 180°-soft 180°" with a single soft 180° pulse that selectively inverts the CH(2)O magnetizations. Theoretical analysis in this study demonstrates the correctness of this approach in principle. Validation on a milk phantom allowed us to investigate and discuss advantages and disadvantages of the proposed srINEPT with respect to the original srINEPT. Furthermore, comparison of different selective pulses made it possible to demonstrate that the proposed srINEPT experiment is not sensitive to errors in pulse length, offset, and B(1) field strength of the selective pulse when ReBurp pulse is used for selective refocusing.


Assuntos
Algoritmos , Análise de Alimentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Leite/química , Compostos de Fósforo/análise , Isótopos de Fósforo/análise , Processamento de Sinais Assistido por Computador , Animais , Bovinos , Ésteres/análise
11.
Environ Sci Technol ; 46(22): 12575-82, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23102111

RESUMO

Indoor dust is thought to be a source of human exposure to perfluorocarboxylates (PFCAs) and perfluorosulfonates (PFSAs), but exposures to emerging organofluorine compounds, including precursors to PFCAs and PFSAs via indoor dust, remain unknown. We report an analytical method for measuring several groups of emerging phosphorus-containing fluorinated compounds, including polyfluoroalkyl phosphoric acid diesters (diPAP), perfluorophosphonates (PFPA), and perfluorophosphinates (PFPIA), as well as perfluoroethylcyclohexane sulfonate (PFECHS) in indoor dust. This method was used to analyze diPAP, PFPA, and PFPIA levels in 102 residential dust samples collected in 2007-2008 from Vancouver, Canada. The results indicated a predominant and ubiquitous presence of diPAPs (frequency of detection 100%, mean and median ΣdiPAPs 7637 and 2215 ng/g). Previously measured median concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and fluorotelomer alcohols (FTOHs) in the same samples were 14-74 times lower than ΣdiPAP levels, i.e. 71 ng/g PFOS, 30 ng/g PFOA, and 152 ng/g ΣFTOHs. PFPAs and PFPIAs were detected in 62% and 85% of samples, respectively, at concentrations nearly 3 orders of magnitude lower than diPAPs (median 2.3 ng/g ΣPFPAs and 2.3 ng/g ΣPFPIAs). PFECHS was detected in only 8% of dust samples. To the best of our knowledge, this is the first report of these compounds in indoor dust. In this study, diPAP concentrations represented 98% ± 7% of the total measured analytes in the dust samples. Detection of diPAPs at such high concentrations in indoor dust may represent an important and as-yet unrecognized indirect source of PFCA exposure in humans, given the identified biotransformation pathways. Identifying the sources of diPAPs to the indoor environment is a priority for future research to improve air quality in households.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Poeira/análise , Exposição Ambiental , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Fluorocarbonos/análise , Compostos de Fósforo/análise , Colúmbia Britânica , Cromatografia Líquida/métodos , Habitação , Humanos , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
12.
Environ Sci Technol ; 46(19): 10572-8, 2012 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-22994917

RESUMO

Differences in biogenic phosphorus (P) compounds between sediment and suspended particles in aquatic environments are important for understanding the mechanisms of internal P loading, but these differences are still unknown. We used solution-state (31)P-nuclear magnetic resonance spectroscopy ((31)P NMR) with NaOH-ethylenediaminetetraacetic extraction to detect the multiple P compounds in suspended particles and sediment in the eutrophic Lake Kasumigaura, including orthophosphate monoesters, orthophosphate diesters, pyrophosphate, and polyphosphate. We tested the hypothesis that there is a significant difference between these groups in suspended particles and sediment. Biogenic P other than orthophosphate was found in significantly higher proportions in suspended particles (74.3% of total P) than in sediment (25.6%). Orthophosphate monoesters were comparatively more abundant in suspended particles, as indicated by the ratio of orthophosphate diesters to monoesters (average, 0.31 for suspended particles; 1.05 for sediment). The compounds identified as orthophosphate monoesters by (31)P NMR spectroscopy originated mainly from phospholipids (α-glycerophosphate and ß-glycerophosphate) and ribonucleic acid (RNA-P), whereas the orthophosphate diesters included mostly DNA (DNA-P). These results suggest that the dynamics of orthophosphate diesters, the production of DNA-P, or the degradation of phospholipids, play an important role in P cycling in Lake Kasumigaura.


Assuntos
Sedimentos Geológicos/análise , Espectroscopia de Ressonância Magnética/métodos , Compostos de Fósforo/análise , Compostos de Fósforo/química , DNA/química , Ácido Edético/química , Eutrofização , Sedimentos Geológicos/química , Glicerofosfatos/química , Japão , Lagos , Fosfatos , Fósforo/química , Isótopos de Fósforo
13.
J Environ Qual ; 41(5): 1695-701, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23099962

RESUMO

Both the high phosphorus (P) content and P bioavailability of the animal feed coproducts of the corn-ethanol industry could potentially contribute to increased manure and soil P levels and associated environmental issues (e.g., eutrophication). Therefore, a detailed modeling of total P mass flow to the coproducts (i.e., dry distillers grains with solubles, DDGS) was performed. Distribution of P between inorganic P and phytase-hydrolyzable P forms was quantified for selected coproducts (thin stillage, DDGS, modified DDGS [mDDGS]). The P mass balance indicated that although corn is the major P contributor to the coproducts (80.2%), a substantial portion (19.4%) comes from yeast addition. Of the two components constituting DDGS, wet distillers grains and condensed solubles, the latter contributes to only one-third of the mass but, importantly, yields 70.9% of P. The phytase enzyme used, , was very effective in hydrolyzing the nonorthophosphate P components of thin stillage, DDGS and mDDGS. Our results would help track P movement during various dry-grind processing steps and formulate strategies for phytase enzyme supplementation to various postfermentation coproducts from corn-ethanol plants.


Assuntos
Fósforo/química , Zea mays/química , Animais , Bovinos , Etanol/síntese química , Feminino , Masculino , Compostos de Fósforo/análise , Ácido Fítico/análise
14.
Water Environ Res ; 84(11): 2037-44, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23356019

RESUMO

The role of ferrous iron in the phosphorus cycle of an aquatic ecosystem is poorly understood because of a lack of suitable methods to quantitatively evaluate ferrous iron phosphorus (FIP) phases. Using sediments sampled from Fubao Bay of Dianchi Lake in China, a novel extraction method for FIP using 2,2'-bipyridine was explored. Total phosphorus and iron in the sediments ranged from 1.0 to 5.0 mg/g (dry weight) and 28.5 to 90.6 mg/g, respectively. Organic content (as indicated by loss on ignition or LOI) and iron(II) ranged from 3.1 to 27.0% and 26.5 to 64.9 mg/g, respectively. The dissolution dynamics of FIP extraction with a low solid/liquid ratio (1:25) indicated that a single application of 0.2% 2,2'-bipyridine extracted both iron(II) (Fe(II)) and phosphorus (as PO4(3-)) in sediments with different organic contents with low efficiency. The extraction efficiency of Fe(II) was improved by alteration of the solid/liquid ratio, but the effect was limited. However, addition of a 1:1000 solid/liquid ratio of 0.5 M potassium chloride to a 0.2% 2,2'-bipyridine solution significantly accelerated extraction of FIP with the release of Fe(II) and phosphorus toward equilibrium at approximately 150 hours. Further investigation demonstrated that 2,2'-bipyridine exhibited a higher selectivity in distinguishing FIP from phosphorus bound to ferric (Fe(III)) oxides or precipitated by calcium (Ca2+). Air-drying sediments significantly decreased the amount of extracted FIP, which indicates that fresh, wet sediment should be used in this type of FIP extraction. Based on experimental results using the proposed extraction protocol, (1) FIP in sediments of Fubao Bay had a predominant status in the lake sediment and accounted for 23.4 to 39.8% of total phosphorus, and (2) Fe(II)(FIP) released in the extraction is directly proportional to phosphorus(FIP) (Fe(II)(FIP) = 2.84 x P(FIP) + 0.0007; R2 = 0.97) with an average molar ratio of Fe(II)(FIP)/P(FIP) of 2.7. This study shows that FIP extraction with 2,2'-bipyridine is a robust method for releasing ferrous iron associated with phosphorus. Further, the high percentage of FIP in total phosphorus (40%) measured in the study site using this extraction method suggests that FIP might have been often underestimated in previous studies.


Assuntos
Compostos Ferrosos/análise , Sedimentos Geológicos/análise , Compostos de Fósforo/análise , 2,2'-Dipiridil/química , Fosfatos de Cálcio/química , Compostos Ferrosos/química , Compostos de Fósforo/química , Solubilidade
15.
Water Sci Technol ; 65(7): 1190-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22437015

RESUMO

Phosphorus (P) is often the limiting nutrient for algal growth, and P in sediments can be released under suitable conditions. To control P release, in-situ control technology with lanthanum (La) modified bentonite clay (Phoslock(®)) was proposed and its effectiveness was tested and evaluated both in laboratory and field trials. The results of static and dynamic simulation experiments under different environmental conditions showed that with the application rate of Phoslock(®) at 0.5 kg/m(2), the orthophosphate (PO(4)-P) concentration of the overlying water decreased to a low level (≤0.02 mg/L) within 10 days. Even under anaerobic and high pH (pH = 9.0) conditions, the phosphate release suppression efficiency reached 98.3%, and the P-release rate was -8.20 mg/m(2) d (negative value indicates P adsorption by Phoslock(®)). The monitoring data of the field sediments rehabilitation project were consistent with the results achieved in laboratory experiments, thus showing that the application of Phoslock(®) could inhibit the internal P release effectively.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/análise , Compostos de Fósforo/análise , Poluentes Químicos da Água/análise , Silicatos de Alumínio/química , Bentonita/química , Argila , Eutrofização , Concentração de Íons de Hidrogênio , Oxigênio/química
16.
J Environ Qual ; 40(3): 751-66, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21546661

RESUMO

In the past decades, environmental scientists have become increasingly involved in developing novel approaches for applying emerging spectroscopic techniques to complex environmental matrices. The objective of this review is to convey the most common chemical species of phosphorus reported for soils, sediments, model systems, and waste materials based on analyses by four spectroscopic techniques: X-ray absorption near-edge structure, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and Raman spectroscopy. Unique information is provided by each technique at a level of specificity that depends in part on matrix complexity. The X-ray absorption near-edge structure and nuclear magnetic resonance techniques reveal inorganic and organic P species in intact environmental matrices or in chemical extracts, whereas the Fourier transform infrared and Raman techniques can provide more specific bonding information about mineral or adsorbed P species in model analogs of matrix components. The most common P species in soils and sediments as indicated by spectroscopy are hydroxyapatite and octacalcium phosphate minerals, phosphate adsorbed on Fe- and Al-oxides, pyrophosphates and polyphosphates, phosphate mono- and di-esters, and phosphonates. Continued advancements in spectroscopic methods should improve speciation-based models of P mobilization and transformations in the environment.


Assuntos
Monitoramento Ambiental/métodos , Espectroscopia de Ressonância Magnética/métodos , Fósforo/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Espectroscopia por Absorção de Raios X/métodos , Simulação por Computador , Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/análise , Espectroscopia de Ressonância Magnética/instrumentação , Fósforo/análise , Compostos de Fósforo/análise , Compostos de Fósforo/química , Solo/análise , Solo/química , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação , Análise Espectral Raman/instrumentação , Resíduos/análise , Espectroscopia por Absorção de Raios X/instrumentação
17.
Artigo em Inglês | MEDLINE | ID: mdl-21469009

RESUMO

The objective of this study was to assess the suitability of statistical and the k-C* models to projecting treatment performance of constructed wetlands by applying the models to predict the final effluent concentrations of a pilot field-scale constructed wetlands system (CWs) treating animal farm wastewater. The CWs achieved removal rates (in g/m(2).d) ranging from 7.1-149.8 for BOD(5), 49.8-253.8 for COD and 7.1-47.0 for NH(4)-N. Generally, it was found that the statistical models developed from multiple regression analyses (MRA) were stronger in predicting final effluent concentrations than the k-C* model. However, both models were inadequate in predicting the final effluent concentrations of NO(3)-N. The first-order area-based removal rate constants (k, m/yr) determined from the experimental data were 200.5 for BOD(5), 80.1 for TP and 173.8 for NH(4)-N and these indicate a high rate of pollutant removal within the CWs.


Assuntos
Modelos Estatísticos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Áreas Alagadas , Agricultura , Compostos de Alúmen/química , Irlanda , Compostos de Nitrogênio/análise , Compostos Orgânicos/análise , Compostos de Fósforo/análise , Projetos Piloto , Esgotos/química
18.
Zhongguo Zhong Yao Za Zhi ; 36(8): 963-7, 2011 Apr.
Artigo em Zh | MEDLINE | ID: mdl-21809563

RESUMO

OBJECTIVE: The effect of the different fertilizing levels on yields and main active components of Pinellia ternata from Sichuan was studied under the cultivated condition, in order to provide theoretical basis for the standardized cultivation. METHOD: Using one of the wild populations of P. ternate from Sichuan as tested material, the experiment was performed with orthogonal designing methods L25 (5(3)). During growth and development period, agronomic traits such as number of sprouting, inflorescence and bulblets were counted. After harvesting, main chemical compositions, growth and proliferation rates were determined. RESULT: In different fertilizing levels, the P. ternata from Sichuan showed the same growth rhythm, though there were significant difference (P < 0.05) among the average emergence rate,whereas extremely significant difference (P < 0.01) were detected among the average ratio of bolting, the average bulbils, individual growth rate, individual proliferation rate, beta-sitosterol and alkaloid content under different fertilizing levels. Nitrogenous fertilizer that affected the content of alkaloids and beta-sitosterol were extremely significant (P < 0.01), whereas phosphate and potassium fertilizer had no significant effect. The effect of fertilizer factor and inter effects on beta-sitosterol showed no significant effect, but have influence on other indexes. CONCLUSION: The optimum fertilizer composition was 315 kg x hm(-2) of nitrogen, 225 kg x hm(-2) of P2O5 and 270 kg x hm(-2) of K2O.


Assuntos
Alcaloides/análise , Fertilizantes , Pinellia/química , Pinellia/crescimento & desenvolvimento , Sitosteroides/análise , Compostos de Nitrogênio/análise , Fosfatos/análise , Compostos de Fósforo/análise , Compostos de Potássio/análise
19.
Artigo em Zh | MEDLINE | ID: mdl-21619850

RESUMO

OBJECTIVE: To establish a ion chromatography method for determination of phosphorus oxychloride in the air of workplace. METHOD: The phosphorus oxychloride in the air of workplace was collected by absorb liquid and turned into hydrochloric acid, then separated in column and detected with conductivity detector, qualified by elution time and quantified by peak height or peak area. RESULTS: The linear range of phosphorus oxychloride in air of workplace was 0.72 ∼ 5.76 µg/ml with its correlation coefficient 0.9999. The detecting limit of the method was 0.12 µg/ml. The smallest detecting concentration of the method was 0.08 mg/m(3) for 15 L sampling air. Relative standard deviation was 3.3% ∼ 6.2% and the recovery was 97.8% ∼ 103.8%. The sample could be resaved at room temperature at least for seven days. CONCLUSION: The indicators of the method correspond GBZ/T 210.4-2008«Guide for establishing occupational health standards-Part 4: Determination methods of air chemicals in workplace¼. It is a good method to determine phosphorus oxychloride in the air of workplace.


Assuntos
Poluentes Ocupacionais do Ar/análise , Cromatografia Gasosa/métodos , Compostos de Fósforo/análise , Íons/análise , Local de Trabalho
20.
Environ Pollut ; 288: 117732, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34256284

RESUMO

Phosphorus (P) discharges from human activities result in eutrophication of lakes. We investigated whether the forms of phosphorus (P) in rivers with high effluent loads flowing through urban areas of Sapporo, Japan, were transformed when transported downstream into a eutrophic lake, namely Lake Barato. We hypothesized that the inorganic P supplied from the rivers might be transformed to organic forms in the lake. The results showed that soluble reactive phosphorus (SRP) and particulate inorganic phosphorus (PIP) dominated in the river discharge to the lake. Suspended solids in the rivers were rich in iron (Fe) so PIP was associated with Fe. A comparison of the concentrations at the river mouth and 4.5 km downstream showed that the concentrations of SRP and PIP were lower at 4.5 km downstream than at the river mouth, whereas the concentrations of organic P (i.e., dissolved organic phosphorus and particulate organic phosphorus) were similar. The results from solution 31P nuclear magnetic resonance spectroscopy of lake water showed that pyrophosphate was only present in the particulate fraction, while orthophosphate diesters (DNA-P) were only present in the dissolved fraction. Riverine samples contained orthophosphate (ortho-P) only, while lake samples contained ortho-P, orthophosphate monoesters, and DNA-P. The results suggest that the P forms, particularly those of dissolved P, shifted from inorganic to organic forms as the water was discharged from the river to the lake.


Assuntos
Compostos de Fósforo , Poluentes Químicos da Água , China , Monitoramento Ambiental , Eutrofização , Humanos , Lagos , Espectroscopia de Ressonância Magnética , Fósforo/análise , Compostos de Fósforo/análise , Rios , Poluentes Químicos da Água/análise
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