Consulta: creatorFacets:"Stavrakakis, Christophe"
Registros recuperados: 13
Data/hora: 07/06/2024 01:12:16

Optimization of Air Backwash Frequency during the Ultrafiltration of Seawater
Provedor de dados: 5
Autores: Cordier, C; Eljaddi, Tarik; Ibouroihim, Nadjim; Stavrakakis, Christophe; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
The main objective of this paper is to study the effect of new air backwash on dead-end ultrafiltration of seawater with a pilot at semi-industrial scale (20 m3/day). To control membrane fouling, two different backwashes were used to clean the membrane: classical backwash (CB) and new air backwash (AB) that consists of injecting air into the membrane module before a classical backwash. To evaluate the efficiency of AB and CB, a resistance in series model was used to calculate each resistance: membrane (Rm), reversible (Rrev) and irreversible (Rirr). The variation of the seawater quality was considered by integrating the turbidity variation versus time. The results indicate clearly that AB was more performant than CB and frequency of AB/CB cycles was...
Tipo: Text
Palavras-chave: Ultrafiltration; Seawater treatment; Air backwash; Fouling control.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00625/73682/73146.pdf

Removal of pathogens by ultrafiltration from sea water
Provedor de dados: 5
Autores: Cordier, Clémence; Stavrakakis, Christophe; Morga, Benjamin; Degrémont, Lionel; Voulgaris, Alexandra; Bacchi, Alessia; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
Among water treatment processes, ultrafiltration is known to be efficient for the elimination of micro-organisms (bacteria and viruses). In this study, two pathogens were targeted, a bacterium, Vibrio aestuarianus and a virus, OsHV-1, with the objective to produce high quality water from seawater, in the case of shellfish productions. The retention of those microorganisms by ultrafiltration was evaluated at labscale. In the case of OsHV-1, the protection of oysters was validated by in vivo experiments using oysters spat and larvae, both stages being highly susceptible to the virus. The oysters raised using contaminated seawater which was then subsequently treated by ultrafiltration, had similar mortality to the negative controls. In the case of V....
Tipo: Text
Palavras-chave: Ultrafiltration; Biosecurisation; Pathogen retention; Sea water; OsHV-1; Shellfish production.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00634/74576/74466.pdf

Ultrafiltration for environment safety in shellfish production: removal of oyster gametes in hatchery effluents
Provedor de dados: 5
Autores: Cordier, Clémence; Stavrakakis, Christophe; Dupuy, Beatrice; Papin, Mathias; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
Triploid oysters are favoured by the aquaculture industry because of their sterility, which results in two advantages: a faster growth than natural oysters and a constant quality throughout all the year, which is attractive for consumers. In France, these oysters are mainly produced by mating natural and tetraploid oysters whose production poses a risk for marine environmental biodiversity if biological material is released into the environment. Therefore, effluents from farms which could produce those kinds of oysters must be treated. The objective of this work was to treat shellfish hatchery effluents by ultrafiltration. The retention of gametes by the membrane, was validated for different scenario, 5 log removals were obtained, and their viability was...
Tipo: Text
Palavras-chave: Ultrafiltration; Hatchery effluents; Oyster gametes removal; Marine biodiversity.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00472/58333/60886.pdf

Projet TREFFLE : Traitement d’effluents d’écloserie conchylicole par filtration membranaire et colonne de dépression
Provedor de dados: 5
Autores: Stavrakakis, Christophe; Cordier, Clemence.
Le présent projet se propose d’étudier l’apport de deux procédés de traitement des eaux dans les écloseries/nurseries conchylicoles face au risque de rejet de matériel biologique tétraploïde dans l’environnement. Les procédés de traitement des eaux testés dans le cadre du projet TREFFLE sont, un dispositif de recirculation d’eau type air-lift, le procédé Coldep, et les procédés membranaires, procédés largement utilisés dans d’autres problématiques de traitement des eaux. Pour les deux procédés, les conditions de fonctionnement seront étudiées en conditions douces, c’est à dire avec une eau de mer préfiltrée sur filtre à sable (seuil de filtration de 25-30 µm) et des ajouts de gamètes et larves d’huître creuse ont été réalisés afin de déterminer les...
Tipo: Text
Palavras-chave: Effluents d’écloserie; Traitement de l’eau; Production d’huîtres tétraploïdes; Colonne de dépression; Filtration membranaire; Hatchery effluent; Water Treatment; Tetraploid oysters production; Depression Column; Membrane filtration.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00394/50502/51241.pdf

Air Backwash Efficiency on Organic Fouling of UF Membranes Applied to Shellfish Hatchery Effluents
Provedor de dados: 5
Autores: Cordier, Clemence; Stavrakakis, Christophe; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
Among all the techniques studied to overcome fouling generated in dead-end filtration, the injection of air during backwashes proved to be the most effective. Indeed, shear stress engendered by the two-phase flow enhanced particle removal on membrane surface. This work aims to study the injection of air to drain the membranes before backwash. Firstly, the efficiency of this backwash procedure was evaluated during the ultrafiltration of seawater on a semi industrial pilot plant using different operating conditions. Then, the treatment of seawater, doped with oyster gametes to simulate the filtration of shellfish hatchery effluents, was performed to confirm the hydraulic performance of the air backwash. Indeed, the release of gametes, expulsed by exotic...
Tipo: Text
Palavras-chave: Ultrafiltration; Air backwash; Efficiency; Viability of organic matter; Shellfish hatchery effluents.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00451/56270/57842.pdf

Bilan des connaissances sur la qualité de l'eau dans la zone du polder conchylicole de Bouin - Projet LEAUPOLD
Provedor de dados: 5
Autores: Hatt, Philippe-jacques; Stavrakakis, Christophe; Buchet, Vincent; Dupuy, Beatrice.
Le polder conchylicole de Bouin (Vendée) est le principal bassin français de production de naissains d’huîtres creuses issus d’écloseries. Depuis 2007, et malgré l’installation de dispositifs de traitement de l’eau, des anomalies dans les élevages voire des mortalités affectent la production des écloseries et nurseries du secteur, ainsi que celle de microalgues en grand volume d'une entreprise spécialisée. Les observations des professionnels orientent la recherche de la cause de ces mortalités sur les contaminants chimiques, notamment les pesticides utilisés par l'agriculture, dont les exploitations du polder agricole, qui jouxtent le polder conchylicole. Comme l'ont montré de nombreux travaux, certains de ces produits altèrent la qualité de l’eau de mer...
Tipo: Text
Palavras-chave: Bassin Loire-Bretagne; Baie de Bourgneuf; Environnement; Conchyliculture; Qualité de l'eau; Pollution chimique; Bassin versant; Mortalité; Zone côtière; Loire-Bretagne district; Bourgneuf bay; Environment; Shellfish aquaculture; Water quality; Chemical pollution; Watershed; Mortality; Coastal zone.
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00280/39165/37726.pdf

Ultrafiltration for environmental safety in shellfish production: A case of bloom emergence
Provedor de dados: 5
Autores: Cordier, Clémence; Voulgaris, Alexandra; Stavrakakis, Christophe; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
The process of ultrafiltration (UF) of natural seawater often encounters the problems of variation in water quality and coastal blooms. To validate the feasibility of UF in shellfish farms, this study compared the hydraulic performance and pollutant removal efficiency of the UF process with those of the commonly used treatments that combine several filtration steps with UV disinfection. The comparison was conducted in the cases of natural seawater and a coastal bloom. Given that the UF process encountered this specific pollution, this study evaluated the filtration performance of the UF process and the retention of total suspended solids (TSS), bacteria, phytoplankton, and zooplankton. A real coastal bloom was considered in the case study of an...
Tipo: Text
Palavras-chave: Ultrafiltration; Environmental safety; Aquaculture; Shellfish culture; Coastal bloom.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00684/79658/82422.pdf

Adsorption sur charbon actif pour une amélioration de la qualité de l’eau en aquaculture – ADAQUA. Application aux écloseries conchylicoles
Provedor de dados: 5
Autores: Stavrakakis, Christophe; Dupuy, Beatrice; Hequet, Valerie.
En ecloserie conchylicole, comme dans le milieu ouvert, une bonne qualite dfeau est indispensable aux differentes etapes des elevages, de la fecondation jusqu'a la fixation du naissain. Or, malgre les traitements mis en place en amont des differents etablissements du polder de Bouin (filtration fine et desinfection par rayonnements Ultra-Violets), la non-atteinte du stade de larves D dans les ecloseries dfhuitres ou le mauvais developpement des larves en elevage ont pu etre constates depuis 2008, parfois de facon simultanee dans plusieurs etablissements. Ceci reflete une deterioration ponctuelle de la qualite de lfeau. Une pollution de type biologique ayant pu etre ecartee, lfinfluence dfune contamination chimique sur ces dereglements est suspectee....
Tipo: Text
Palavras-chave: Crassostrea gigas; Élevage larvaire; Contamination chimique; Adsorption sur charbon actif; Capteurs passifs.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00416/52765/53628.pdf

Désinfection de l’eau de mer – DESIMER Etude des sous-produits de désinfection
Provedor de dados: 5
Autores: Stavrakakis, Christophe; Papin, Mathias; Dupuy, Beatrice; Riou, Karen; Penisson, Christian; Nourry, Max; Hatt, Philippe-jacques; Buchet, Vincent; Palvadeau, Hubert.
L'eau qui alimente des structures d’élevage ou encore des plateformes expérimentales aquacoles (et potentiellement l’eau qui en est issue) peut être contaminée par des agents pathogènes infectant les coquillages, et plus particulièrement les huîtres, ou encore par des agents pathogènes entériques représentant un risque pour les consommateurs. Par ailleurs, la production possible d'huîtres tétraploïdes dans les installations d’élevage implique l’étude de solutions de traitement adaptées pour éviter tout rejet de gamètes, larves ou naissain d’animaux polyploïdes dans l'environnement. Le projet DESIMER a donc pour objectif d’étudier et de comparer différentes techniques de désinfection de l’eau de mer : la chloration, l’ozonation et le rayonnement UV afin de...
Tipo: Text
Palavras-chave: Désinfection; Traitement de l’eau; Sous-produits; Vibrio aestuarianus; OsHV-1; Crassostrea gigas.; Disinfection; Water Treatment; By-products; Vibrio aestuarianus; OsHV-1; Crassostrea gigas.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00376/48756/49141.pdf

Optimization of diatom   Hasleao strearia   cultivation in different mediums and nutrients
Provedor de dados: 5
Autores: Arsad, S; Stavrakakis, Christophe; Turpin, Vincent; Rossa, P; Risjani, Y; Sari, L A; Prasetiya, F S; Mouget, J-l.
Hasleaostrearia is a marine diatom that can feed oysters. This study aimed to cultivate H.ostrearia in the following media: seawater (SW), seawater filtered by activated carbon (SW+CA), and drilling water (DW). The three-water media were supplemented with two types of nutrients, Walne-Conway+silica (CS) and ES-1/3 Provasoli (P), leading to a six experiment series. The cultures were grown in 200 mL and 400 mL respectively. The dilution cycle was every 3 - 4 day for 200 mL volume and every 4 - 5 days for the 400 mL volume for 20 - 40 days or until the cultures showed a decrease in growth. The microalgae exhibited a better growth in SW and SW+CA CS, whereas DW showed a diminishing number of cells in both the CS and P medium. The highest value of Emn in the...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00484/59552/62535.pdf

Rapport d'activités 2015 de l'Unité SG2M : Santé, Génétique et Microbiologie des Mollusques
Provedor de dados: 5
Autores: Lapegue, Sylvie; Renault, Tristan; Bechemin, Christian; Le Guyader, Soizick; Stavrakakis, Christophe; Rivet, Florence.
L’unité SG2M est structurée pour aborder de manière intégrée les domaines de la santé animale et de la santé humaine liée à production, à la consommation de coquillages, et à la qualité microbiologique du littoral. Ainsi, dans le cadre d’un continuum recherche/surveillance/expertise, et d’une approche pluridisciplinaire, l’unité cherche à développer des connaissances concernant les interactions entre agents infectieux, hôtes et environnement chez les mollusques marins, et les cycles de contamination. Dans le domaine de la recherche, les activités de l’unité sont déclinées selon quatre axes structurants : (1) la microbiologie sanitaire et les voies de transfert des agents pathogènes humains dans l’environnement côtier, (2) l’étude des maladies affectant les...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00319/43055/42562.pdf

Ultrafiltration: A solution to recycle the breeding waters in shellfish production
Provedor de dados: 5
Autores: Cordier, Clemence; Charpin, Lisa; Stavrakakis, Christophe; Papin, Mathias; Guyomard, Killian; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
Shellfish profession is jeopardized by water quality problem that concerns inlet, with the need to protect the animals from pathogens contaminations, and effluents potentially harmful for the environment with the presence of pathogens, nutrients or organic matter. In this study, ultrafiltration was tested to answer these issues. The objective of the work was two-fold: (i) treat a real effluent from an oyster breeding, the pilot had to continuously face a water containing organic matter and pathogens and (ii) use ultrafiltered water to feed an oyster spat. The process was proved to be efficient in terms of total suspended solids (TSS) and bacterial retention, and especially for Vibrio bacteria, some of whom are potentially harmful for shells. The...
Tipo: Text
Palavras-chave: Ultrafiltration; Aquaculture; Shellfish effluent; Spat protection.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00478/58951/61539.pdf

Culture of Microalgae with Ultrafiltered Seawater: A Feasibility Study
Provedor de dados: 5
Autores: Cordier, Clémence; Guyomard, Killian; Stavrakakis, Christophe; Sauvade, Patrick; Coelho, Franz; Moulin, Philippe.
The culture of microalgae is important for the production and maintenance of bivalves. One of the major challenges is to maintain the reliability of microalgae forages over the long term. The aim of this work is to use Ultrafiltered (UF) seawater to cultivate them. Thus, cultures in a volume of 300 L of 2 species of microalgae Tetraselmis and T-isochrysis, were monitored in UF water (membrane pore size: 20 nm) and in sea water usually used on the Ifremer mollusk experimental platform of Bouin (France) (Prefiltration, 3 filtrations and 2 UV). The major result is the securing of microlagae cultures with the absence of parasites in all cultures supplied with ultrafiltered water, unlike analyses of the various control cultures. In the case of T-isochrysis, 3...
Tipo: Text
Palavras-chave: Microalgae; Ultrafiltration; Water Purification; Shellfish Production.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00630/74182/73785.pdf