title: In situ measurement with diffusive gradients in thin films: effect of biofouling in freshwater.
abstract: Concerning in situ passive sampler deployment, several technical priorities must be considered. In particular, deployment time must be sufficiently long not only to allow a significant quantity to be accumulated to facilitate analysis but also to ensure that the signal is above the quantification limit and out of the blank influence. Moreover, regarding the diffusive gradient in thin films (DGT) technique, deployment time must also be sufficiently long (at least 5 days) to avoid the interactions of the solutes with the material diffusion layer of the DGT and for the steady state to be reached in the gel. However, biofouling occurs in situ and modifies the surface of the samplers. In this article, we propose a kinetic model which highlights the biofouling effect. This model was able to describe the mitigation of the flux towards the DGT resin observed on Cd, Co, Mn, Ni and Zn during a 22-day deployment in the Seine River. Over a period of 22 days, biofouling had a significant impact on the DGT concentrations measured, which were decreased twofold to threefold when compared to concentrations measured in unaffected DGTs.
authors.affiliation: Irstea, UR HBAN Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS 10030, 92761, Antony Cedex, France. emmanuelle.uher@irstea.fr.|FIRE FR-3020, 4 Place Jussieu, 75005, Paris, France. emmanuelle.uher@irstea.fr.
authors.forename: Emmanuelle
authors.identifier: http://orcid.org/0000-0002-3379-0040
authors.initials: E
authors.lastname: Uher
authors.affiliation: IFREMER, Centre de Bretagne, ZI de la Pointe du Diable, CS 10070, 29280, Plouzané, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Compère
authors.affiliation: Irstea, UR HBAN Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS 10030, 92761, Antony Cedex, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Combe
authors.affiliation: IFREMER, Centre de Bretagne, ZI de la Pointe du Diable, CS 10070, 29280, Plouzané, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Mazeas
authors.affiliation: Irstea, UR HBAN Hydrosystèmes et Bioprocédés, 1 rue Pierre-Gilles de Gennes, CS 10030, 92761, Antony Cedex, France.|FIRE FR-3020, 4 Place Jussieu, 75005, Paris, France.|Anses, 14 rue Pierre et Marie Curie, 94701, Maisons-Alfort Cedex, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Gourlay-Francé
mesh_terms: D057219:Biofouling; D004058:Diffusion; D004784:Environmental Monitoring; D005618:Fresh Water; D045483:Rivers
keywords: Biofouling; DGT; Field deployment; Metals; Passive sampler; Seine River