摘要：Highlights•Retention of pathogens (virus and bacteria) in sea water by ultrafiltration.•High removal values byin vitrotests but not total retention byin vivotest.•Effect of the pathogen concentrations on ultrafiltration retention.•Biosecurisation of shellfish production by ultrafiltration.•Validation of the results at an semi industrial scale whatever the quality of seawater.AbstractAmong 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 aestuarianusand 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 byin vivoexperiments 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 ofV. aestuarianus, ultrafiltration allowed a high retention of the bacteria in seawater with concentrations below the detection limits of the 3 analytical methods (flow cytometry, direct seeding and seeding after filtration to 0.22 µm). Thus, the quantity ofV. aestuarianuswas at least, 400 times inferior to the threshold known to induce mortalities in oysters. Industrial scale experiment on a several months period confirmed the conclusion obtained at lab scale on theVibriobacteria retention. Indeed, no bacteria from this genus, potentially harmful for oysters, was detected in permeate and this, whatever the quality of the seawater treated and the bacteria concentration upstream of the membrane. Moreover, the resistance of the process was confirmed with a stability of hydraulic performances over time for two water qualities and even facing an algal bloom. In terms of retention and resistance, ultrafiltration process was validated for the treatment of seawater towards the targeted pathogenic microorganisms, with the aim of biosecuring shellfish productions.
关键词：Ultrafiltration;Biosecurisation;Pathogen retention;Sea water;OsHV-1;Shellfish production
