Consulta: subjectFacets:"Sulphide"
Registros recuperados: 5
Data/hora: 10/06/2024 06:29:17

Effect of sulphate concentration and sulphide desorption on the combined removal of organic matter and sulphate from wastewaters using expanded granular sludge bed (EGSB) reactors
Provedor de dados: Electronic Journal of Biotechnology
Autores: Valdés,Freddy; Muñoz,Edmundo; Chamy,Rolando; Ruiz,Gonzalo; Vergara,Christian; Jeison,David.
During the application of anaerobic processes to high sulphate concentration wastewaters, operational problems are expected due to the occurrence of sulphate reduction. Sulphide production reduces effluent quality and may produce inhibition. The application of Expanded Granular Sludge Bed (EGSB) reactors for the combined removal of organic matter and sulphate was studied at different COD/sulphate and 3 values of pH. During the EGSB reactor operation, most of the sulphide remains in the liquid phase reducing effluent quality. The inclusion of a desorption column in the recirculation of the EGSB reactor promotes mass transfer to the gas phase, reducing the sulphide concentration in the liquid phase, significantly decreasing the chemical oxygen demand of the...
Tipo: Journal article
Palavras-chave: Anaerobic digestion; EGSB; Sulphate reduction; Sulphide.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000400004

Ecophysiological and metabolic adaptations to sulphide exposure of the oyster Crassostrea gigas
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Moullac, Gilles; Cheize, Marie; Gastineau, Olivier; Daniel, Jean-yves; Le Coz, Jean-rene; Huvet, Arnaud; Moal, Jeanne; Pouvreau, Stephane; Van Wormhoudt, A; Samain, Jean-francois.
The purpose of this study is to examine the response of the oyster Crassostrea gigas to sulphide at different biological scales. A first experiment was designed to measure for 20 h the clearance (CR) and oxygen consumption (OC) rates of oysters exposed at different concentrations of sulphide (0, 3, 6, 12, 20, and 40 mu M). The second experiment was carried out to evaluate the metabolic adaptations to chronic sulphide exposure for 10 days by measuring PK and PEPCK enzyme activities, succinate and alanine content, the adenylate energy charge (AEC), and the activity of the electron transport system (ETS)in whole oysters at above 20 mu M. PK and PEPCK mRNAs and enzyme activities have been measured in adductor muscle. When exposed to sulphide above 20 mu M, CR...
Tipo: Text
Palavras-chave: ATP; AEC; Electron transport system; Succcinate; Alanine; Phosphoenolpyruvate carboxykinase; Pyruvate kinase; Oxygen consumption; Clearance rate; Crassostrea gigas; Sulphide; Oyster.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3924.pdf

Méthodes électrochimiques pour l'analyse in situ de composés bioactifs en milieu océanique
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Lacombe, Marielle.
The implementation of in situ autonomous observatories for biogeochemicalstudies in the open ocean water column and in deep-sea chemosynthetic environments is crucial for the understanding of these ecosystems. We focussed this study on silicate and sulphide, two key compounds of the marine food chain. A voltammetric method for sulphide measurements on silver electrode is presented, and a new method for quantitative determination based on the solubility difference between silver chloride and silver sulphide is proposed. A completely reagentless method for silicate measurements is developed using molybdate and protons produced during molybdenum oxidation. These analyticaldevelopments allowed us to validate a submersible potentiostat, first step toward a new...
Tipo: Text
Palavras-chave: Water masses; Drake Passage; Sensor; Electrochemistry; Sulphide; Silicate; Deep sea chemosynthetic environments; Open ocean; In situ autonomous observatories; Masses d'eau; Passage de Drake; Capteur; Voltammétrie; Électrochimie; Sulfure; Acide silicique; Écosystèmes profonds; Océan ouvert; Observatoires in situ autonomes.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/these-3921.pdf

Etude de la structure des communautés bactériennes du sédiment et de l'écologie de Vibrio aestuarianus pathogène de l'huître creuse Crassostrea gigas dans deux sites ostréicoles
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Azandegbe, Afi.
Since several years, the French oyster farming copes with high mortality affecting juveniles and some adults of the Pacific oyster Crassostrea gigas. Studies conducted in the framework of a multidisciplinary project (MOREST) showed that mortality was related to several factors like physiological and genetic status of oyster, pathogens including bacteria of the genus Vibrio, and revealed that the sediment, on which the oyster cages are installed, might play a particular role. This has been suggested because of the concomitance of the mortalities and increased toxic compounds like ammonia and sulphides in the sediment. Moreover, the presence of Vibrio bacteria in the sediment indicates a dual role of sediment in the mortality onset. The physico-chemical...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Bactéries; Vibrio aestuarianus; Écologie; Sédiment; Ammonium; Sulfures; Oyster; Crassostrea gigas; Bacteria; Vibrio aestuarianus; Ecology; Sediment; Ammonia; Sulphide.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00032/14277/11561.pdf

Impact du sédiment sur les mortalités estivales de naissain d'huîtres creuses Crassostrea gigas en baie de Quiberon
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bedier, Edouard; Knoery, Joel Radford; Fleury, Pierre-gildas; Quiniou, Francoise; Langlade, Aime; Cozic, Amandine; Delesmont, Edith; Delesmont, Régis; Caisey, Xavier; Lecureuil, Laetitia.
The phenomenon of summer mortalities of the Pacific cupped oyster Crassostrea gigas is observed in France since the beginning of the 90's. These mortalities are classically associated to younger stages and summer temperatures and occur during the reproduction period of the animal. The studies undertaken during the project Morest (2001-2005), showed that a number of biological and environmental risks, the interaction of them induces lethal stresses for animals in physiological weakness, exists in summer. Among these risks, that which is withstood by the oysters bred close to the sediment proved to be significant in intertidal areas. In Quiberon bay (southern Brittany, France), the breeding practices of sowing oysters in deep water is thus likely to expose...
Tipo: Text
Palavras-chave: Huître; Crassostrea gigas; Mortalité; Sédiment; Composé réduit; Flux; Sulfure; Ammonium; Oyster; Crassostrea gigas; Mortality; Sediment; Reduced compound; Flux; Sulphide; Ammonia.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/00108/21956/19550.pdf