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1.
No Shinkei Geka ; 40(1): 49-54, 2012 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-22223523

RESUMEN

We performed 3D-CT angiography (3D-CTA) with contrast injection to a feeding artery through a selectively introduced catheter into the intercostal artery in a patient with spinal hemangioblastoma. It revealed a relative three-dimensional (3D) anatomy between a tumor body, feeding arteries, draining veins, and surrounding vertebrae with superior resolution to 3D-CTA with intravenous contrast injection. This observation was used for preoperative planning facilitating tumor removal, through reconstructed 3D fly-through animation providing intraoperative identification and obliteration of feeding arteries. This examination was carried out without difficulty by utilizing IVR-CT/angio system (IVR: interventional radiology) which combines angiographic and CT equipment with a single fluoroscopy table, because it does not require a room-to-room transfer of the patient with the catheter left cannulated. DSA detection for any spinal lesions, neoplastic or vascular ones, is always better assisted by 3D-CTA with the IVR-CT/angio system (IVR-CTA).


Asunto(s)
Angiografía/métodos , Hemangioblastoma/diagnóstico por imagen , Hemangioblastoma/cirugía , Radiografía Intervencional/métodos , Neoplasias de la Médula Espinal/diagnóstico por imagen , Neoplasias de la Médula Espinal/cirugía , Tomografía Computarizada por Rayos X/métodos , Adulto , Humanos , Imagenología Tridimensional , Masculino , Cuidados Preoperatorios
2.
Mar Drugs ; 8(3): 594-607, 2010 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-20411117

RESUMEN

The lactate dehydrogenases (LDHs) in hagfish have been estimated to be the prototype of those in higher vertebrates. The effects of high hydrostatic pressure from 0.1 to 100 MPa on LDH activities from three hagfishes were examined. The LDH activities of Eptatretus burgeri, living at 45-60 m, were completely lost at 5 MPa. In contrast, LDH-A and -B in Eptatretus okinoseanus maintained 70% of their activities even at 100 MPa. These results show that the deeper the habitat, the higher the tolerance to pressure. To elucidate the molecular mechanisms for adaptation to high pressure, we compared the amino acid sequences and three-dimensional structures of LDHs in these hagfish. There were differences in six amino acids (6, 10, 20, 156, 269, and 341). These amino acidresidues are likely to contribute to the stability of the E. okinoseanus LDH under high-pressure conditions. The amino acids responsible for the pressure tolerance of hagfish are the same in both human and hagfish LDHs, and one substitution that occurred as an adaptation during evolution is coincident with that observed in a human disease. Mutation of these amino acids can cause anomalies that may be implicated in the development of human diseases.


Asunto(s)
Anguila Babosa/fisiología , L-Lactato Deshidrogenasa/química , L-Lactato Deshidrogenasa/metabolismo , Modelos Moleculares , Músculo Esquelético/enzimología , Miocardio/enzimología , Adaptación Fisiológica , Secuencia de Aminoácidos , Animales , Estabilidad de Enzimas , Anguila Babosa/clasificación , Humanos , Datos de Secuencia Molecular , Filogenia , Presión , Estructura Terciaria de Proteína , Alineación de Secuencia , Temperatura
3.
J Hazard Mater ; 160(2-3): 662-7, 2008 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-18511186

RESUMEN

The combined flushing and oxidation process using acetic acid and ozone has been used successfully to remove trichloroethylene (TCE) completely from contaminated soil. In this study, the effects of humic acid, a fraction of the organic matter in soil, over the performance of TCE decomposition was evaluated. TCE decomposition by ozone was enhanced by the presence of humic acid at concentrations lower than 8mgCL(-1) and then inhibited at higher concentrations. It is possible that the presence of the soluble humic acid fraction during the ozonation of TCE in acetic acid solutions produces hydroxyl radicals during the TCE ozonation which appears to be the reason for the enhanced TCE decomposition rate. Solid humic acid reduced TCE decomposition rate by acting as an ozone scavenger. Similarly, sorbed TCE reduced the amount of TCE available for decomposition by ozone in solution.


Asunto(s)
Acetatos/química , Sustancias Húmicas/análisis , Oxidantes Fotoquímicos/química , Ozono/química , Tricloroetileno/química , Benzopiranos/química , Radicales Libres/análisis , Indicadores y Reactivos , Solubilidad , Soluciones
4.
Mar Pollut Bull ; 56(12): 2059-66, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18834603

RESUMEN

Dredged spoil (DS) was used as a silt and clay additive in the construction of artificial tidal flats from mountain sand (MS). As the ratio of DS in the sediment media increased, the number of emerging macrobenthos increased. The composition of the macrobenthic community was also affected by the addition of DS, and the changes might be dependent on the ratio of DS to MS. In addition, the macrobenthos in the artificial tidal flats was more abundant than that in the control tidal flat, which was constructed with natural tidal flat sediment. With a silt and clay content of 25%, polychaetes Ceratonereis erythraeensis and Capitella sp. and the gastropod Batillaria cumingii were dominant, whereas no bivalves were present. With less silt and clay (5% and 10%), the bivalves Ruditapes philippinarum and Musculista senhousia were observed in the artificial flats, while their numbers in the control tidal flat were lower.


Asunto(s)
Ecosistema , Sedimentos Geológicos/química , Suelo/análisis , Animales , Invertebrados , Japón , Larva , Océanos y Mares , Movimientos del Agua
5.
Clin Biochem ; 40(3-4): 274-7, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17222397

RESUMEN

OBJECTIVES: Lysophospholipase D (lysoPLD)/autotaxin regulates the blood levels of lysophosphatidic acid (LPA), and we designed a serum lysoPLD assay for use in clinical laboratory testing. DESIGN AND METHODS: LysoPLD activity was assessed based on the amount of choline released with lysophosphatidylcholine as the substrate. RESULTS AND CONCLUSIONS: It was confirmed that the lysoPLD assay can be applied to clinical laboratory testing. The serum lysoPLD activity in healthy female subjects was significantly higher than that in the male subjects.


Asunto(s)
Técnicas de Laboratorio Clínico , Complejos Multienzimáticos/sangre , Fosfodiesterasa I/sangre , Hidrolasas Diéster Fosfóricas/sangre , Pirofosfatasas/sangre , Femenino , Humanos , Masculino , Sensibilidad y Especificidad , Factores Sexuales
6.
Chemosphere ; 68(2): 281-6, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17300831

RESUMEN

Techniques for enhancing the biodegradation of oil-contaminated fine soils in a slurry-phase bioreactor were investigated. Using a model system consisting of kaolin particles containing adsorbed n-dodecane as a diesel fuel surrogate, we investigated how increasing the temperature and adding a surfactant and various hydrophobic support media affected the biodegradation rate of n-dodecane. Increasing the temperature from 25 to 35 degrees C decreased the time required for complete degradation of n-dodecane by 30%, from 110h to 80h. Addition of the surfactant polyethylene glycol p-1,1,3,3-tetramethylbutylphenyl ether decreased the degradation time to less than 48h at 35 degrees C, although a high concentration of the surfactant (3000mgl(-1)) was required. We suspect that the surfactant increased the degradation rate by solubilizing the n-dodecane into the solution phase in which the microorganisms were suspended. We tested five types of organic polymers as support media for the microorganisms and found that the biodegradation time could be reduced by approximately 50% with a support medium made from polyurethane; in the presence of this medium, only 36h was required for complete decomposition at 35 degrees C. The reduction in the degradation time was probably due to transfer of the n-dodecane from the soil to the support medium, which improved contact between the n-dodecane and the microorganisms. The polyurethane support medium bearing the microorganisms was stable and could be reused.


Asunto(s)
Biodegradación Ambiental , Reactores Biológicos , Petróleo/metabolismo , Contaminantes del Suelo/metabolismo , Adsorción , Alcanos/metabolismo , Tensoactivos/farmacología
7.
J Hazard Mater ; 147(3): 1051-5, 2007 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-17360113

RESUMEN

The purpose of this study is to develop froth flotation to separate polyvinyl chloride (PVC) from automobile shredder residue (ASR) plastic mixtures of variable composition. Some polymers in ASR polymer mixtures have similar density and hydrophobicity with PVC and thus selective flotation of PVC from ASR polymer mixtures cannot be achieved. The present study focused on the surface modification of PVC with ozonation, and then the modified PVC can be separated from other polymers by the following froth flotation. The results of this study indicate that the selective recovery of PVC from real ASR polyethylene tetra pethelate (PET), polymethyl methacrylate (PMMA), polybutyl methacralate (PBMA), ethyl acrylate (EA), polycarbonate (PC) and rubber mixtures can be accomplished in a three-step process involving a gravity separation, ozonation and froth flotation. The rubber was removed from other heavy ASR (PVC, PET, PMMA, PBMA, EA and PC) polymers by froth flotation without mixing. It was found that ozonation process produced the desired difference in contact angle required (from 89.5 to 73.0 degrees ) for separation of PVC from other heavy ASR polymers, whereas the contact angles of other polymers was slightly decreased. The most of the load ASR, i.e. about 72.4% is floated away and 27.6% was settled down. The highest component 96.7% of PVC was recovered in the settled fraction. As a result of this research effort, the surface modification of PVC with ozonation can be efficiently useful to separate the PVC from other similar density ASR mixed polymers.


Asunto(s)
Automóviles , Ozono/química , Cloruro de Polivinilo/aislamiento & purificación , Administración de Residuos/métodos , Interacciones Hidrofóbicas e Hidrofílicas
8.
Mar Pollut Bull ; 54(10): 1582-5, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17692339

RESUMEN

The objective of this study is to clarify the effect of ulvoid (Ulva spp.) accumulation on the structure and function of an eelgrass bed by the coast of Iwakuni, Seto Inland Sea, Japan. We monitored eelgrass shoot density and volume of ulvoid accumulation in the study site and evaluated effects of the accumulated ulvoid canopy on the percent survival, seedling density, growth rates, photosynthetic photon flux density (PPFD) and carbon contents of eelgrass. Eelgrass shoot density decreased by the accumulation of ulvoid. Also, seedling density decreased by the increase in the ulvoid volumes. Shoot density, seedling density and leaf elongation were negatively correlated with ulvoid volume. Carbon contents in eelgrass decreased by the accumulation of ulvoid (canopy height: 25cm). These results suggest that accumulation of ulvoid bloom has significant negative impacts on the structure and function of eelgrass bed, i.e. decreases in vegetative shoot density, seedling density, shoot height and growth rate.


Asunto(s)
Ecosistema , Ulva/crecimiento & desarrollo , Zosteraceae/fisiología , Carbono/análisis , Japón , Fotosíntesis/fisiología , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrollo , Raíces de Plantas/química , Brotes de la Planta/fisiología , Densidad de Población , Rizoma/química , Análisis de Supervivencia
9.
J Hazard Mater ; 137(3): 1618-23, 2006 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-16797833

RESUMEN

The fate of heavy metals during a separation process for automobile shredder residues (ASR) was investigated. A washing method to remove heavy metals from the ASR was also investigated. Although the separation process was not designed for removal of heavy metals, but for the recovery of reusable materials, the heavy metal content in the ASR was efficiently decreased. The concentrations of Pb, Cr and Cd in ASR were effectively reduced by a nonferrous metals removal process, and the As concentration was reduced by the removal of light dusts during the separation process. Five heavy metals (As, Se, Pb, Cr, Cd) remaining in the ASR after the separation process satisfied the content criteria of the Environmental Quality Standards for Soil (EQSS), while the concentrations of As, Se, Pb in the leachate from the remaining ASR did not satisfy the elution criteria of the EQSS. After additional washing of the remaining ASR with a pH 1 acid buffer solution, the As, Se, and Pb concentrations satisfied the EQSS for elution. These results indicate that an ASR residue can be safely recycled after a separation process, followed by washing at acidic pH.


Asunto(s)
Automóviles , Metales Pesados/aislamiento & purificación
10.
Nihon Geka Gakkai Zasshi ; 107(3): 150-7, 2006 May.
Artículo en Japonés | MEDLINE | ID: mdl-16734275

RESUMEN

UNLABELLED: We studied the possibility that cryopreserved human heart cells could be transplanted with some advantage. METHOD: Cells derived human atrial tissues (control group (n = 13)), cryopreserved cells (cell-cryopreservation group (n = 23), and cells derived cryopreserved tissue (tissue-cryopreservation group (n = 29)) were cultured for 15 days. The cell proliferation was compared between control and cryopreservation group by growth curves. BasicFGF, TGFbeta-1, IL-6, IL-8, and cell cycle were measured at pre and post-cryopreservation. Mixed Lymphocyte-heart cell culture established by PBL and heart cells was evaluated by PBL proliferation. Transplanted cells were evaluated by visually and histology. RESULTS: Cryopreserved cells were proliferated much more than control cells (p < 0.0001). The growth factors were increased, and cytokines were decreased by cryopreservation (p < 0.05). The cryopreserved cell cycles were shifted to G2 + M from G1 + G0 period. Cryopreserved cells stimulated PBL less than non-cryopreserved cells (p < 0.0001). Transplanted cryopreserved cell were survived. CONCLUSION: Cryopreserved human heart cells can be transplanted, and proliferated much more than non-cryopreserved cells. Cryopreservation enables the human cells to be more prolific, and reduced the immunogenicity of them. The transplanted cryopreserved cells survived and formed cardiac-like tissue.


Asunto(s)
Antígenos/inmunología , Proliferación Celular , Criopreservación , Trasplante de Corazón/métodos , Animales , Células Cultivadas , Criopreservación/métodos , Sustancias de Crecimiento/análisis , Humanos , Ratas , Ratas Endogámicas Lew , Ratas Wistar
11.
Clin Biochem ; 38(11): 1023-6, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16098503

RESUMEN

OBJECTIVES: Platelet release of alpha granule-derived CXC chemokines and dense granule-derived serotonin in plasma samples was evaluated. METHODS: Concentrations of the CXC chemokines beta-TG and PF4 were assayed by an enzyme immunoassay; serotonin was measured by an HPLC method. RESULTS: Beta-TG and PF4 were more easily released than serotonin by in vitro procedures. Use of the anti-platelet cocktail CTAD and preservation of the samples at 4 degrees C were necessary to accurately measure beta-TG and PF4, but not serotonin. CONCLUSIONS: Assaying serotonin may be useful for assessing platelet activation in vivo as a laboratory test because of facile preparation of plasma samples.


Asunto(s)
Plaquetas/metabolismo , Quimiocinas CXC/metabolismo , Factor Plaquetario 4/metabolismo , Serotonina/metabolismo , beta-Tromboglobulina/metabolismo , Adenosina/farmacología , Adulto , Plaquetas/efectos de los fármacos , Quimiocinas CXC/sangre , Ácido Cítrico/farmacología , Dipiridamol/farmacología , Ácido Edético/farmacología , Humanos , Activación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Serotonina/sangre , Teofilina/farmacología
12.
Ultrason Sonochem ; 12(4): 277-82, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15501710

RESUMEN

To evaluate the feasibility of ultrasonic regeneration of granular activated carbon (GAC), desorption of trichloroethylene (TCE) from GAC by ultrasound was investigated at 20 kHz. About 64% of TCE was desorbed from 5 g of GAC loaded with 6.5 mg TCE for 1 h in ultrasonic field and TCE desorbed to liquid phase were rapidly degraded by ultrasound. 34-43% of stoichiometrically calculated chloride, final degradation product of TCE, was observed in liquid phase during ultrasonic treatment. However, there was desorption limitation at 20 kHz ultrasound. Despite of prolonged ultrasonic irradiation, desorption efficiency of TCE did not exceed critical value. And also, the higher percentage of TCE was desorbed when a sample of 2 mg TCE/4 g GAC was treated ultrasonically than that of 2 mg TCE/g GAC under the same experimental conditions. These results indicate that desorption of TCE by 20 kHz ultrasound occurred mainly at a nearby surface of GAC. In conclusion, the ultrasonic regeneration showed a possibility as an alternative to chemical and thermal regenerations of GAC.

13.
Chemosphere ; 58(4): 523-7, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15620744

RESUMEN

The objective of this study is to find metal ions that enhance the ozone decomposition of chlorinated organic substances in acetic acid. Although the pseudo-first order degradation rate constant for 2,4-DCP by ozone in acetic acid in addition of Ca2+, Mg2+, Al3+ and Fe2+ were almost the same as that with no metal ion, the degradation rate in addition of Mn2+ and Fe3+ were 2.4 and 4.5 times as high as that with no metal ion, respectively. The presence of Fe3+ enhanced the degradation of 2,4-DCP by ozone in acetic acid because Fe3+-phenolate complex which have high reactivity with ozone was produced by the reaction between 2,4-DCP and Fe3+ in acetic acid.


Asunto(s)
Ácido Acético/química , Hidrocarburos Clorados/metabolismo , Metales/farmacología , Ozono/química , Purificación del Agua/métodos , Biodegradación Ambiental , Cationes , Clorofenoles/metabolismo , Desinfectantes/química , Desinfectantes/metabolismo , Relación Dosis-Respuesta a Droga , Factores de Tiempo , Tricloroetileno/metabolismo
14.
Chemosphere ; 58(1): 57-63, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15522333

RESUMEN

The performance of a garbage disposal system to solubilize and mineralize food wastes through biological solubilization was evaluated through the examination of the effects of operational conditions like water supply volume, water supply frequency and aeration on the amount of waste solubilized, mineralized and accumulated in the reactor. The biological solubilization process consisted of a solubilization reactor and a circulation tank. Food waste and fresh water were supplied into the solubilization reactor with support media. Wastewater from the solubilization reactor was discharged to the circulation tank and water in the circulation tank was periodically pumped back to the solubilization reactor. In case of the total food waste loading of 16 kg m(3-1) d(-1), little carbon (0-5.7%) accumulated in the reactor as long as the system was kept under aerobic condition through large volume of water supply (higher than 3.5 lh(-1)) or applying aeration in the circulation tank. However, 42% of the loaded carbon accumulated under anaerobic condition in low water supply (less than 1.8 lh(-1)). The rest of the waste was either solubilized or mineralized. The aeration in the circulation tank, therefore, was effective to provide similar solubilization and mineralization as the large volume of water supply. However, frequency of feeding at the large volume of water supply had no significant effect on the amount of waste solubilization and mineralization.


Asunto(s)
Reactores Biológicos , Alimentos , Eliminación de Residuos/métodos , Biodegradación Ambiental , Carbono/metabolismo , Eliminación de Residuos/instrumentación , Solubilidad
15.
Chemosphere ; 136: 153-9, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25985303

RESUMEN

Ozonation is believed to improve the biodegradability of organic compounds. In the present study, degradation of nonylphenol ethoxylates (NPEOs) was monitored in hybrid treatment systems consisting of ozonation and microbial degradation processes. We found that ozonation of NPEOs decreased, rather than increased, the biodegradability under certain conditions. The timing of ozonation was a definitive factor in determining whether ozonation increased or decreased the biodegradation rates of NPEOs. Initial ozonation of NPEOs prior to biodegradation reduced the rate of dissolved organic carbon (DOC) removal during the subsequent 14 d of biodegradation, whereas intermediate ozonation at the 9th day of biodegradation improved subsequent DOC removal during 14 d of NPEO biodegradation. Furthermore, reduction of DOC removal was also observed, when initial ozonation prior to biodegradation was subjected to cetyl alcohol ethoxylates. The production of less biodegradable intermediates, such as mono- and dicarboxylated polyethylene glycols (MCPEGs and DCPEGs), was responsible for the negative effect of ozonation on biodegradability of NPEOs. DCPEGs and MCPEGs were produced by biodegradation of polyethylene glycols (PEGs) that were ozonolysis products of the NPEOs, and the biodegradability of DCPEGs and MCPEGs was less than that of the precursor PEGs. The results indicate that, if the target chemicals contain ethoxy chains, production of PEGs may be one of the important factors when ozonation is considered.


Asunto(s)
Contaminantes Ambientales/metabolismo , Glicoles de Etileno/metabolismo , Polietilenglicoles/metabolismo , Biodegradación Ambiental , Ácidos Carboxílicos , Contaminantes Ambientales/química , Glicoles de Etileno/química , Polietilenglicoles/química
16.
Physiol Plant ; 116(1): 1-11, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12207656

RESUMEN

An important biochemical feature of autotrophs, land plants and algae, is their incorporation of inorganic nitrogen, nitrate and ammonium, into the carbon skeleton. Nitrate and ammonium are converted into glutamine and glutamate to produce organic nitrogen compounds, for example proteins and nucleic acids. Ammonium is not only a preferred nitrogen source but also a key metabolite, situated at the junction between carbon metabolism and nitrogen assimilation, because nitrogen compounds can choose an alternative pathway according to the stages of their growth and environmental conditions. The enzymes involved in the reactions are nitrate reductase (EC 1.6.6.1-2), nitrite reductase (EC 1.7.7.1), glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 1.4.1.13-14, 1.4.7.1), glutamate dehydrogenase (EC 1.4.1.2-4), aspartate aminotransferase (EC 2.6.1.1), asparagine synthase (EC 6.3.5.4), and phosphoenolpyruvate carboxylase (EC 4.1.1.31). Many of these enzymes exist in multiple forms in different subcellular compartments within different organs and tissues, and play sometimes overlapping and sometimes distinctive roles. Here, we summarize the biochemical characteristics and the physiological roles of these enzymes. We also analyse the molecular evolution of glutamine synthetase, glutamate synthase and glutamate dehydrogenase, and discuss the evolutionary relationships of these three enzymes.

17.
Water Res ; 37(1): 150-4, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12465796

RESUMEN

Multi-stage ozonation-biological treatment process for dissolved organic carbon (DOC) removal was evaluated to apply for drinking water treatment. Waters with different types of DOC were used, i.e. a reservoir water for drinking water supply, a secondary effluent from a municipal wastewater treatment plant and a solution of humic substances extracted from leaf mold. The multi-stage ozonation-biological treatment process was compared with conventional single-stage ozonation-biological treatment process. Amount of DOC removed in biological treatment was defined as amount of biodegradable dissolved organic carbon (BDOC) in influent of biological treatment. DOC removal in the multi-stage ozonation-biological treatment was higher than that in the conventional single-stage ozonation-biological treatment with the same total ozonation time for the reservoir water and humic substances solution. Moreover, three- or four-stage ozonation for 5 min followed by biological treatment (total ozonation time 15 or 20 min) showed higher removal of DOC than the single-stage ozonation (60 min) and biological treatment. The higher DOC removal in the multi-stage treatment was due to the production of BDOC by ozonation. The long-term ozonation was not effective to produce BDOC because most of ozone was utilized to oxidize BDOC produced in the early stage of ozonation. In the multi-stage treatment, ozonation was effective to decompose refractory DOC and to produce BDOC because BDOC was removed by biological treatment. However, multi-stage ozonation-biological treatment was not effective for the secondary effluent. The reason seems to be high concentration of ozone scavengers in that water and low reactivity of DOC for ozone.


Asunto(s)
Carbono/aislamiento & purificación , Oxidantes Fotoquímicos/química , Ozono/química , Purificación del Agua/métodos , Reactores Biológicos , Sustancias Húmicas , Compuestos Orgánicos/aislamiento & purificación , Solubilidad
18.
Water Res ; 37(11): 2595-8, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12753836

RESUMEN

Performance on the ozonation of hazardous chemicals in non-aqueous solutions, i.e. organic solvents, was studied in comparison with those in water. The specific conclusions obtained from this study are as follows: the rate of decomposition and the specific amount of decomposition per ozone consumption for orange II were higher in organic solvents like acetic acid, acetone, ter-butyl alcohol than in distilled water. The rates of trichloroethylene decomposition in organic solvents like acetic acid, acetone, and ethyl acetate were also higher than those in distilled water.


Asunto(s)
Residuos Peligrosos , Oxidantes Fotoquímicos/química , Ozono/química , Solventes/química , Purificación del Agua/métodos , Tricloroetileno/química , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua
19.
Water Res ; 37(8): 1729-36, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12697217

RESUMEN

Biodegradation rates of polycyclic aromatic hydrocarbons (PAHs) in spilled oil stranded on tidal flats were evaluated using model reactors to clarify the effects of non-aqueous phase liquid (NAPL) on the biodegradation of PAHs in stranded oil on tidal flat with special emphasis on the relationship between dissolution rates of PAHs into water and viscosity of NAPL. Biodegradation of PAHs in NAPL was limited by the dissolution rates of PAHs into water. Biodegradation rate of chrysene was smaller than that of acenaphtene and phenanthrene due to the smaller dissolution rates. Dissolution rates of PAHs in fuel oil C were smaller than those in crude oil due to high viscosity of fuel oil C. Hence, biodegradation rates of PAHs in fuel oil C were smaller than those in crude oil. Biodegradation rates of PAHs in NAPL with slow rate of decrease like fuel oil C was slower than those in NAPL with rapid rate of decrease like crude oil. The smaller rate of decrease of fuel oil C than crude oil was due to the higher viscosity of fuel oil C. Therefore, not only the dissolution rate of PAHs but also the rates of decrease of NAPL were important factors for the biodegradation of PAHs.


Asunto(s)
Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Ecosistema , Monitoreo del Ambiente , Sedimentos Geológicos/química , Solubilidad
20.
Water Res ; 37(19): 4631-6, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14568049

RESUMEN

The accumulation of calcium on biological activated carbon (BAC) and their effects on adsorption of synthetic organic chemicals (SOCs) were studied using BAC, which have been operated for 5 (BAC5.0) and 3.5 (BAC3.5) years in a pilot-scale water purification plant, and granular activated carbon (GAC) preloaded with fulvic acid and/or calcium. The major inorganic material accumulated on BAC was calcium. The amounts of calcium on BAC5.0 and BAC3.5 were 36.6 and 29.7 mg g(-1), respectively. Seventy-one percent of calcium existed as calcium carbonate in both BACs. BAC5.0 had higher amount of accumulated calcium than BAC3.5 even though both BACs have already exhausted for NOM in the influent in 1-year operation, suggesting that calcium carbonate gradually accumulated on BAC even after the 3.5 years of operation. The isotherms of GAC preloaded with fulvic acid and/or calcium clearly indicated that the calcium accumulation on GAC reduced adsorption capacity for simazine. The conclusion also confirmed by significant recovery of adsorption capacity of both BACs by acid-washing to remove accumulated calcium from BACs. The difference of adsorption capacity between BAC3.5 and BAC5.0 was caused not only by the difference of adsorbed NOM but also the difference in the amount of accumulated calcium.


Asunto(s)
Carbono/química , Contaminantes del Agua/aislamiento & purificación , Purificación del Agua/métodos , Adsorción , Filtración , Concentración de Iones de Hidrógeno , Compuestos Orgánicos
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