The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

Miren P. Cajaraville - One of the best experts on this subject based on the ideXlab platform.

  • Short- and long-term responses and recovery of mussels Mytilus edulis exposed to Heavy Fuel oil no. 6 and styrene
    Ecotoxicology, 2014
    Co-Authors: Pamela Ruiz, Maren Ortiz-zarragoitia, Amaia Orbea, Sjur Vingen, Anne Hjelle, Thierry Baussant, Miren P. Cajaraville
    Abstract:

    Biomarkers have the potential to be used to assess the impact of anthropogenic discharges in marine waters. We have used a suite of biomarkers spanning from enzymatic to histopathological alterations and general stress responses to assess the short- and long-term impact on mussels Mytilus edulis of Heavy Fuel oil no. 6 and styrene. Mussels were exposed for 5 months, with a refilling of the exposure system, to a water soluble fraction of Heavy Fuel and, then, kept for a month in clean water for recovery. In a second experiment, mussels were exposed to styrene for 19 days and maintained in clean water for up to 4 months. Chemical body tissue levels reflected the weathering processes of these compounds. Acyl-CoA oxidase activity was induced in oil-exposed mussels after refilling, whereas styrene inhibited it after 19 days of exposure and after 2 weeks in clean water. Gamete development and alkali-labile phosphate levels suggest that neither oil nor styrene behaved as endocrine disruptors. Neutral red retention time was lower in treated groups than in controls. Lysosomal membrane stability was significantly reduced in exposed groups and recovered after withdrawal of oil but not after removal of styrene. Neither oil nor styrene exposure affected the condition index except for the reduction seen in mussels exposed to oil for 1 month. Biomarker response index discriminated exposed mussels, which showed higher values, and returned to control levels after recovery. Results obtained from these pilot experiments can help to identify relevant monitoring tools to assess the impact of oil and chemicals in marine spill scenarios.

  • Responses of conventional and molecular biomarkers in turbot Scophthalmus maximus exposed to Heavy Fuel oil no. 6 and styrene.
    Aquatic Toxicology, 2012
    Co-Authors: Pamela Ruiz, Stéphane Le-floch, Michael Theron, Maren Ortiz-zarragoitia, Amaia Orbea, Miren P. Cajaraville
    Abstract:

    Abstract Several accidental spills in European coastal areas have resulted in the release of different toxic compounds into the marine environment, such as Heavy Fuel oil type no. 6 in the “Erika” and “Prestige” oil spills and the highly toxic styrene after the loss of the “Ievoli Sun”. There is a clear need to develop tools that might allow assessing the biological impact of these accidental spills on aquatic organisms. The aim of the present study was to determine the short-term effects and recovery after exposure of juvenile fish ( Scophthalmus maximus ) to Heavy Fuel oil no. 6 and styrene by using a battery of molecular, cell and tissue level biomarkers. Turbots were exposed to styrene for 7 days and to the diluted soluble fraction of the oil (10%) for 14 days, and then allowed to recover in clean seawater for the same time periods. cyp1a1 transcript was overexpressed in turbots after 3 and 14 days of exposure to Heavy Fuel oil, whereas ahr transcription was not modulated after Heavy Fuel oil and styrene exposure. pparα transcription level was significantly up-regulated after 3 days of treatment with styrene. Liver activity of peroxisomal acyl-CoA oxidase (AOX) was significantly induced after 14 days of oil exposure, but it was not affected by styrene. Hepatocyte lysosomal membrane stability (LMS) was significantly reduced after exposure to both treatments, indicating that the tested compounds significantly impaired fish health. Both AOX and LMS values returned to control levels after the recovery period. No differences in gamete development were observed between Fuel- or styrene- exposed fish and control fish, and vitellogenin plasma levels were low, suggesting no xenoestrogenic effects of Fuel oil or styrene. While styrene did not cause any increase in the prevalence of liver histopathological alterations, prevalence of extensive cell vacuolization increased after exposure to Heavy Fuel oil for 14 days. In conclusion, the suite of selected biomarkers proved to be useful to determine the early impact of and recovery from exposure to tested compounds in turbot.

  • Transcriptional responses of cancer-related genes in turbot Scophthalmus maximus and mussels Mytilus edulis exposed to Heavy Fuel oil no. 6 and styrene
    Ecotoxicology, 2012
    Co-Authors: Pamela Ruiz, Amaia Orbea, Jeanette M. Rotchell, Miren P. Cajaraville
    Abstract:

    Recent spills in European waters have released polycyclic aromatic hydrocarbons, important components of Heavy Fuel oil, and the hydrocarbon styrene. Heavy Fuel oil and styrene are classified as potentially genotoxic and carcinogenic. Here we investigate transcription of genes involved in cancer development in the liver of juvenile turbots and in the digestive gland of mussels exposed to Heavy Fuel oil and to styrene and after a recovery period. In turbot, oil produced a significant up-regulation of p53 and gadd45α after 14 days exposure. cyclin G1 was up-regulated after 7 days treatment with styrene. In mussels, ras was down-regulated in both treatments after the recovery periods. No mutations in ras hotspots were detected in exposed mussels. gadd45α was up-regulated after the recovery period of the styrene experiment. Overall, transcriptional responses differed in mussels compared to turbot. Turbot responded to hydrocarbon exposure by triggering cell cycle arrest ( p53 ) and DNA repair ( gadd45α ).

Jorge Barroso - One of the best experts on this subject based on the ideXlab platform.

  • behavior of a high capacity steam boiler using Heavy Fuel oil part i high temperature corrosion
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a highcapacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed. D 2004 Elsevier B.V. All rights reserved.

  • behavior of a high capacity steam boiler using Heavy Fuel oil part ii cold end corrosion
    Fuel Processing Technology, 2004
    Co-Authors: Félix Barreras, Jorge Barroso
    Abstract:

    An experimental study has been performed on a high-capacity steam boiler burning Heavy Fuel oil to assess cold-end corrosion damages. In this second part of the research, acid corrosion in the rotary continuous-regenerative air heaters (CRAHs) has been analyzed. Corrosion potentiality has been evaluated from both qualitative and quantitative viewpoints. Results have shown that acid corrosion in the CRAHs is reduced when the low-quality Heavy Fuel oil is mixed with a magnesium-based additive. In this research, two commercial additives have been tested: a magnesium oxide-based slurry and an organometallic one. The best results have been obtained when the organometallic additive was used in the treatment of the Heavy Fuel. For this experimental condition, an increase in the useful lifetime of the pie-shaped baskets, as well as a decrease in both the acid dew point temperature (ADT) at the stack gases and the pressure drop (fouling) on the CRAHs have been confirmed.

  • Behavior of a high-capacity steam boiler using Heavy Fuel oil
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a high-capacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed.

Pamela Ruiz - One of the best experts on this subject based on the ideXlab platform.

  • Short- and long-term responses and recovery of mussels Mytilus edulis exposed to Heavy Fuel oil no. 6 and styrene
    Ecotoxicology, 2014
    Co-Authors: Pamela Ruiz, Maren Ortiz-zarragoitia, Amaia Orbea, Sjur Vingen, Anne Hjelle, Thierry Baussant, Miren P. Cajaraville
    Abstract:

    Biomarkers have the potential to be used to assess the impact of anthropogenic discharges in marine waters. We have used a suite of biomarkers spanning from enzymatic to histopathological alterations and general stress responses to assess the short- and long-term impact on mussels Mytilus edulis of Heavy Fuel oil no. 6 and styrene. Mussels were exposed for 5 months, with a refilling of the exposure system, to a water soluble fraction of Heavy Fuel and, then, kept for a month in clean water for recovery. In a second experiment, mussels were exposed to styrene for 19 days and maintained in clean water for up to 4 months. Chemical body tissue levels reflected the weathering processes of these compounds. Acyl-CoA oxidase activity was induced in oil-exposed mussels after refilling, whereas styrene inhibited it after 19 days of exposure and after 2 weeks in clean water. Gamete development and alkali-labile phosphate levels suggest that neither oil nor styrene behaved as endocrine disruptors. Neutral red retention time was lower in treated groups than in controls. Lysosomal membrane stability was significantly reduced in exposed groups and recovered after withdrawal of oil but not after removal of styrene. Neither oil nor styrene exposure affected the condition index except for the reduction seen in mussels exposed to oil for 1 month. Biomarker response index discriminated exposed mussels, which showed higher values, and returned to control levels after recovery. Results obtained from these pilot experiments can help to identify relevant monitoring tools to assess the impact of oil and chemicals in marine spill scenarios.

  • Responses of conventional and molecular biomarkers in turbot Scophthalmus maximus exposed to Heavy Fuel oil no. 6 and styrene.
    Aquatic Toxicology, 2012
    Co-Authors: Pamela Ruiz, Stéphane Le-floch, Michael Theron, Maren Ortiz-zarragoitia, Amaia Orbea, Miren P. Cajaraville
    Abstract:

    Abstract Several accidental spills in European coastal areas have resulted in the release of different toxic compounds into the marine environment, such as Heavy Fuel oil type no. 6 in the “Erika” and “Prestige” oil spills and the highly toxic styrene after the loss of the “Ievoli Sun”. There is a clear need to develop tools that might allow assessing the biological impact of these accidental spills on aquatic organisms. The aim of the present study was to determine the short-term effects and recovery after exposure of juvenile fish ( Scophthalmus maximus ) to Heavy Fuel oil no. 6 and styrene by using a battery of molecular, cell and tissue level biomarkers. Turbots were exposed to styrene for 7 days and to the diluted soluble fraction of the oil (10%) for 14 days, and then allowed to recover in clean seawater for the same time periods. cyp1a1 transcript was overexpressed in turbots after 3 and 14 days of exposure to Heavy Fuel oil, whereas ahr transcription was not modulated after Heavy Fuel oil and styrene exposure. pparα transcription level was significantly up-regulated after 3 days of treatment with styrene. Liver activity of peroxisomal acyl-CoA oxidase (AOX) was significantly induced after 14 days of oil exposure, but it was not affected by styrene. Hepatocyte lysosomal membrane stability (LMS) was significantly reduced after exposure to both treatments, indicating that the tested compounds significantly impaired fish health. Both AOX and LMS values returned to control levels after the recovery period. No differences in gamete development were observed between Fuel- or styrene- exposed fish and control fish, and vitellogenin plasma levels were low, suggesting no xenoestrogenic effects of Fuel oil or styrene. While styrene did not cause any increase in the prevalence of liver histopathological alterations, prevalence of extensive cell vacuolization increased after exposure to Heavy Fuel oil for 14 days. In conclusion, the suite of selected biomarkers proved to be useful to determine the early impact of and recovery from exposure to tested compounds in turbot.

  • Transcriptional responses of cancer-related genes in turbot Scophthalmus maximus and mussels Mytilus edulis exposed to Heavy Fuel oil no. 6 and styrene
    Ecotoxicology, 2012
    Co-Authors: Pamela Ruiz, Amaia Orbea, Jeanette M. Rotchell, Miren P. Cajaraville
    Abstract:

    Recent spills in European waters have released polycyclic aromatic hydrocarbons, important components of Heavy Fuel oil, and the hydrocarbon styrene. Heavy Fuel oil and styrene are classified as potentially genotoxic and carcinogenic. Here we investigate transcription of genes involved in cancer development in the liver of juvenile turbots and in the digestive gland of mussels exposed to Heavy Fuel oil and to styrene and after a recovery period. In turbot, oil produced a significant up-regulation of p53 and gadd45α after 14 days exposure. cyclin G1 was up-regulated after 7 days treatment with styrene. In mussels, ras was down-regulated in both treatments after the recovery periods. No mutations in ras hotspots were detected in exposed mussels. gadd45α was up-regulated after the recovery period of the styrene experiment. Overall, transcriptional responses differed in mussels compared to turbot. Turbot responded to hydrocarbon exposure by triggering cell cycle arrest ( p53 ) and DNA repair ( gadd45α ).

Javier Ballester - One of the best experts on this subject based on the ideXlab platform.

  • behavior of a high capacity steam boiler using Heavy Fuel oil part i high temperature corrosion
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a highcapacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed. D 2004 Elsevier B.V. All rights reserved.

  • Behavior of a high-capacity steam boiler using Heavy Fuel oil
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a high-capacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed.

Félix Barreras - One of the best experts on this subject based on the ideXlab platform.

  • behavior of a high capacity steam boiler using Heavy Fuel oil part i high temperature corrosion
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a highcapacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed. D 2004 Elsevier B.V. All rights reserved.

  • behavior of a high capacity steam boiler using Heavy Fuel oil part ii cold end corrosion
    Fuel Processing Technology, 2004
    Co-Authors: Félix Barreras, Jorge Barroso
    Abstract:

    An experimental study has been performed on a high-capacity steam boiler burning Heavy Fuel oil to assess cold-end corrosion damages. In this second part of the research, acid corrosion in the rotary continuous-regenerative air heaters (CRAHs) has been analyzed. Corrosion potentiality has been evaluated from both qualitative and quantitative viewpoints. Results have shown that acid corrosion in the CRAHs is reduced when the low-quality Heavy Fuel oil is mixed with a magnesium-based additive. In this research, two commercial additives have been tested: a magnesium oxide-based slurry and an organometallic one. The best results have been obtained when the organometallic additive was used in the treatment of the Heavy Fuel. For this experimental condition, an increase in the useful lifetime of the pie-shaped baskets, as well as a decrease in both the acid dew point temperature (ADT) at the stack gases and the pressure drop (fouling) on the CRAHs have been confirmed.

  • Behavior of a high-capacity steam boiler using Heavy Fuel oil
    Fuel Processing Technology, 2004
    Co-Authors: Jorge Barroso, Félix Barreras, Javier Ballester
    Abstract:

    Problems related to the combustion of Heavy oils with high vanadium contents in a high-capacity steam boiler have been analyzed. In this study, two types of additives have been tested both to diminish high-temperature corrosion and to obtain more brittle deposits. Results show that Heavy Fuel oil can be suitably burned in this type of boilers if it is chemically treated with an anticorrosive additive. In this research, the best results have been obtained when the Heavy Fuel oil was mixed with an organometallic additive. The influence of fouling on the behavior of some operational parameters such as the pressure in furnace and pressure drop in superheaters and pipe metal temperature, among others, has been verified. It is concluded that monitoring of these parameters can provide direct information on the degree of fouling, as well as of the effectiveness of the treatment during normal boiler operational conditions. Some other improvements in the atomization and combustion processes due to the use of the organometallic additive have also been observed.