[pt] A quantificação da poliacrilamida sulfonada (PAM-AMPS) por cromatografia de exclusão de tamanho com detecção ultravioleta (SEC-UV) é amplamente utilizada para monitorar processos de recuperação avançada de petróleo (EOR) e o descarte de água. No entanto, não é discutido na literatura como a degradação por hidrólise durante o processo de produção pode afetar o método de monitoramento da concentração do polímero. Assim, este trabalho tem como objetivo avaliar o efeito da degradação por hidrólise da PAM-AMPS em sua quantificação por SEC-UV. Para isso, foi desenvolvido um método de degradação acelerada de hidrólise controlada. Padrões de HPAM-AMPS com diferentes graus de hidrólise (HD = 7 – 33 por cento) foram obtidos. Diferentes métodos de determinação de HD (RMN de 13C, FTIR e retrotitulação) foram avaliados e se mostraram estatisticamente iguais. A quantificação feita por SEC-UV mostrou que a sensibilidade do método é dependente do HD. Erros entre 20 por cento e 40 por cento foram observados a partir de 13 por cento de HD, mas foram irrelevantes até 10 por cento. Esses valores diminuíram com o aumento da concentração do polímero. Os resultados indicam que existem dois fatores compensatórios para a diminuição da absortividade molar devido à substituição de amida por carboxilato: o grupo sulfonato atuando como um cromóforo adicional e um deslocamento para o vermelho nos espectros de absorção devido à formação de ligações de hidrogênio em concentrações mais altas. Assim, este estudo mostra que o aumento da concentração nesse tipo de poliacrilamida sulfonada pode reduzir os erros de quantificação ao minimizar o efeito do HD em amostras aquosas complexas sujeitas à degradação química, destacando a importância de determinar o grau de hidrólise para uma quantificação precisa de PAM-AMPS por SEC-UV. / [en] The quantification of sulfonated polyacrylamide (PAM-AMPS) by size exclusionchromatography with ultraviolet detection (SEC-UV) is widely used to monitorenhanced oil recovery (EOR) processes and water disposal. However, the literaturedoes not provide information on how hydrolysis degradation during the productionprocess can affect the method for monitoring polymer concentration. Thus, thiswork aims to evaluate the effect of hydrolysis degradation of PAM-AMPS on itsquantification by SEC-UV. For this purpose, an accelerated controlled hydrolysisdegradation method was developed. PAM-AMPS standards with different degreesof hydrolysis (HD = 7 – 33 percent) were obtained. Different methods for determiningHD (13C NMR, FTIR, and back titration) were evaluated and found to bestatistically equivalent. Quantification by SEC-UV showed that the method ssensitivity depends on the degree of hydrolysis. Errors ranged from 20 percent to 40 percent starting at 13 percent HD but were negligible below 10 percent HD. These values decreased with increasing polymer concentration. The results indicate two compensatoryfactors for the decrease in molar absorptivity due to the substitution of amide bycarboxylate: the sulfonate group acting as an additional chromophore and a red shiftin the absorption spectra due to hydrogen bonding at higher concentrations. Thus,this study demonstrates that increasing the concentration of this type of sulfonatedpolyacrylamide can reduce quantification errors by minimizing the effect of HD incomplex aqueous samples subject to chemical degradation, highlighting theimportance of determining the degree of hydrolysis for accurate PAM-AMPSquantification by SEC-UV.

La nanoscience est basée sur les changements de propriétés des particules lorsque leur diamètre est inférieur à 100 nm (i.e. nanoparticules, NPs). Devant l’utilisation croissante de tels NPs, et leur déversement probable dans l’environnement, l’évaluation de leurs risques sur la santé humaine et l’environnement est un enjeu majeur. Dans le cadre de la protection des eaux et des sols, l’évaluation de la qualité des eaux de surface est particulièrement importante, notamment dans les zones humides (ZHs), où la dynamique des métaux toxique (i.e. As, Pb, Ni, Cr, Hg) est complexe et dépend des conditions redox du milieu. Comme les NPs de magnétite (nano-Fe3O4), naturelles ou manufacturées, sont reconnues pour leur capacité d’adsorption importante face aux métaux lourds, leurs interactions dans les ZHs ripariennes (ZHRs) avec les ETMs restent critiques quant à leurs impacts directs ou indirects. Ainsi, l’objectif de cette thèse était d’étudier le rôle des nano-Fe3O4 manufacturées (~10nm) et des oxydes de fer naturels sur la dynamique des ETMs dans les eaux de surfaces et les sols de ZHRs. Ainsi, dans un premier volet portant sur des précipités colloïdaux naturels provenant de produits de reoxydation en milieu riparian (soumis à des oscillations redox), la distribution spatiale des éléments a été effectuée par cartographie isotopique nanoSIMS (i.e. 75As-, 56Fe16O-, le soufre (32S-) et la matière organique (12C14N-), alors que la spéciation du soufre a été évaluée par adsorption des rayons X au seuil K du soufre (S) (XANES). Ces analyses ont permis de mettre en évidences les interactions entre les oxydes de fer naturels, la matière organique naturelle (MON) et un métalloïde toxique, l’arsenic. Nos résultats suggèrent, par colocalisation statistique des images nanoSIMS, l’existence de deux types d’interaction : (1) 12C14N-, 32S-, 56Fe16O- et 75As-, et (2) 12C14N-, 32S- et 75As-. La coexistence des formes de S oxydées et réduites, confirmées par les analyses XANES, pourrait être attribuée à la lente cinétique d’oxydation de la MON. Ainsi, ce premier volet montre qu’en plus des interactions MON, oxydes de fer et As, de possibles interactions directes entre As et NOM à travers des groupements fonctionnels soufrés (e.g. thiols) sont aussi possibles en milieu oxydé. Dans un second volet, l’effet des nano-Fe3O4 (~ 10 nm) sur la mobilité des éléments traces (ETs) et des colloïdes, dans l'horizon organominéral d’un sol naturel de ZHR, a été évaluée à l’aide de colonnes de sol. Nos résultats montrent que l’enrobage des nanoparticules semble influencer la mobilité de la MON et des ETs du sol. En effet, la mobilité des ETs semble augmenter en présence de nano-Fe3O4 nus, suggérant des associations où la MON stabiliserait les nanoparticules et augmenterait leur mobilité ainsi que celle des ETs associés. / Nanoscience is based on changes in particle properties when their diameter is below 100 nm (ie nanoparticles, NPs). Considering the increasing use of such NPs and their discharge into the environment, the assessment of their risks to human health and the environment is a major issue. Underneath the protection of waters and soils, the surface water assessment quality is particularly important, especially in wetlands, where the toxic metals dynamic (e.g. As, Pb, Ni, Cr , Hg) is complex and depends on the redox conditions of the environment. As magnetite (nano-Fe3O4), a natural or manufactured NP, is known for its significant adsorption capacity with heavy metals, their interactions in riparian wetlands with trace metals (TMs) remain critical concerning their direct of indirect impact on trace metals (TMs) mobility. The objective of this thesis was to study the role of manufactured nano-Fe3O4 (~ 10nm) and natural iron oxides on the TMs dynamics in wetland surface waters and soils. Therefore, in a first part considering natural colloidal precipitates from reoxidation products from riparian areas (subject to redox oscillations), a spatial distribution of elements was performed using nanoSIMS isotope mapping (i.e. 75As-, 56Fe16O-, sulfur (32S-) and organic matter (12C14N-), while the sulfur speciation was evaluated X-ray adsorption at K edge of the sulfur (S) (XANES). These analyzes allowed to highlight the interactions between natural iron oxides, natural organic matter (NOM) and a toxic metalloid, As. Our results suggest, with a statistical colocalization of nanoSIMS images, the existence of two interaction types: (1) 12C14N-, 32S-, 56Fe16O- and 75As-, and (2) 12C14N-, 32S- and 75As-. The coexistence of the oxidized and reduced forms of S, confirmed by the XANES analyses might be attributed to the slow oxidation kinetic of MON. Thus, this first part shows that in addition to the known interactions between MON, iron oxides and As, a possible direct interaction between As and NOM through sulfur functional groups (e.g. thiols) are also possible in oxidized environment. In a second part, the effect of nano-Fe3O4 (~ 10 nm) on trace elements (TEs) and colloids mobility in the organomineral horizon of a natural wetland soil was assessed using soil columns. Our results show that the nanoparticles coating influences the mobility of NOM and TMs. Indeed, the TMs mobility increases in presence of naked nano-Fe3O4, suggesting associations where NOM stabilizes the nanoparticles and increase the nanoparticles and associated TMs mobility. This mechanism seems less possible with coated nano-Fe3O4 where MON blocks the coating adsorption sites and therefore the adsorption of metals.