Ce travail de thèse a visé le développement d’un outil d’évaluation des flux métalliques annuels émis par les matériaux de couvertures à l’échelle d’un bassin versant, dans le contexte architectural et météorologique de l’Île-de-France. La méthodologie mise en place pour tendre vers ce but repose sur (1) l’évaluation des émissions annuelles de métaux par différents matériaux métalliques de couverture classiquement utilisés dans la région grâce à une approche expérimentale sur bancs d’essais, (2) l’établissement d’un cadre méthodologique pour la modélisation des flux métalliques émis à l’échelle annuelle par les toitures d’un bassin versant qui se base d’une part sur la modélisation des émissions métalliques par les matériaux à différentes échelles spatiales et temporelles (en fonction de la pluviométrie, de la géométrie du toit…) à partir des données obtenues sur les bancs d’essais, et d’autre part sur la quantification des surfaces métalliques des toitures d’un bassin versant. La première partie du travail a donc consisté à développer et à exploiter, sur deux sites différents, des bancs d’essais expérimentaux d’1/2 m², testant 12 matériaux métalliques issus de 5 familles (zinc, cuivre, plomb acier, aluminium), sous différentes mises en oeuvre (panneaux, gouttières, crochets de fixation). 13 espèces métalliques ont été quantifiées dans les eaux de ruissellement collectées ce qui a permis (1) d’acquérir une importante base de données de taux de ruissellement annuels par les différents matériaux, mettant en évidence que les taux de ruissellement annuels obtenus peuvent être assez importants, de l’ordre de plusieurs grammes par m² et par an pour les éléments constitutifs des matériaux, (2) de hiérarchiser ces matériaux en fonction de leur potentiel polluant, à travers la définition d’un indice de contamination métallique se basant sur les émissions de Cd, Cu, Ni, Pb et Zn et permettant de tenir compte des différences de toxicité des métaux. Une modélisation des émissions métalliques par les matériaux à différentes échelles de temps a été réalisée, conduisant à la conclusion que la hauteur de pluie, ainsi que la durée d’exposition sont des paramètres fondamentaux. Il est apparu que la hauteur de pluie seule est suffisante pour modéliser les émissions métalliques par les matériaux à des échelles de temps longues mais ne suffit pas à modéliser ces émissions sur quelques semaines. Un modèle plus complexe, basé sur une hypothèse d’accumulation / dissolution de produits de corrosion à la surface des matériaux donne des résultats satisfaisant à ces échelles de temps plus courtes. L’extrapolation spatiale des résultats de ruissellement obtenus sur les bancs d’essais s’est basé sur d’autres expérimentations, d’abord sur bancs d’essais conduisant à la conclusion que la longueur d’écoulement n’a pas d’influence sur la masse de métal entraînée dans le ruissellement, qui peut être calculée à partir de la hauteur de pluie, de la surface projetée et de l’inclinaison du panneau (qui s’avère négligeable quand elle est inférieure à 50°); puis à l’échelle de toits réels pour une étape de validation. Dans la seconde partie de ce travail, la quantification des surfaces de rampants à l’échelle d’un bassin versant a été effectuée grâce à un outil de classification d’image basé sur l’analyse de la radiométrie des matériaux à partir d’une photo aérienne. Les résultats obtenus sont encourageants, avec environ 75 à 80% des toits qui bien classés à l’issue de la classification. Les principales erreurs reposent sur des confusions de l’outil entre des matériaux de radiométries voisines (ardoise / zinc par exemple, qui peuvent être proches en fonction du degré d’ensoleillement)... / This thesis aimed to develop a tool for the evaluation of annual metallic flows emitted from roofing materials at the scale of a watershed in the architectural and meteorological context of Paris conurbation. The methodology used in this work is based on (1) the assessment of annual metallic emissions from different metallic materials typically used for roofing in the region considered through an experimental test bed, (2) the establishment of a methodological framework for modelling the metallic flow emitted from the roofs of catchment area, which is based both on the modelling of metal emissions from the materials at different spatial and temporal scales (depending on rainfall, geometry of the roof ...) from data obtained on the test bed, and on the quantification of metallic surface areas of roofs in the catchment area. The first part of the work has been based on the exploitation of experimental test beds of 1 / 2 m², testing 12 metallic materials from 5 families (zinc, copper, lead, steel, aluminium) in various implemented (panels, gutters, fixing brackets, exposed on two different sites. 13 metallic species were quantified in the collected runoff which allowed (1) to acquire a large database of annual runoff rates by different materials, highlighting that the annual runoff rates obtained can be fairly important, with an order of magnitude of several grams per square meter per year for the constitutive elements of materials, (2)to classify these materials according to their polluting potential, through the definition of an index of metal contamination taking into consideration the emissions of Cd, Cu, Ni, Pb and Zn and the differences in toxicity of metals. A modelling of metal emissions from the materials at different time scales has been conducted, leading to the conclusion that the rainfall quantity and the duration of exposure are fundamental parameters. It appeared that the rainfall value is sufficient to model metallic emission from materials for long time scales but not enough to model these emissions on a few weeks period. A more complex model, based on an assumption of accumulation / dissolution of corrosion products on the surface of the material gives satisfactory results for these time-scales periods. The spatial extrapolation of results obtained on the test bed scale was based on other experiments, first on test beds, leading to the conclusion that the length of flow has no influence on the mass of metal entrained in the runoff, which can be calculated from the rainfall quantity, the projected area and inclination of the panel (which is negligible when it is below 50 °), and then at the real roof scale for a validation step. In the second part of this work, quantification of surface areas of roofs at the scale of the catchment was conducted using a classification tool image analysis based on the radiometry of materials. The results are encouraging, with about 75 to 80% of roofs ranked on the basis of classification. The main errors are due to confusions between materials presenting nearby radiometry (slate / zinc, for example, which can be close depending on the amount of sunshine). Exploratory work was conducted for the consideration of singular elements - usually realized in metal -, from the use of unified technical documents. The evaluation of metal surfaces concerned has proved difficult to implement in an automatic way because of the small size of these elements, not visible on an aerial photo

An extensive investigation with parallel field andlaboratory exposures has been conducted to elucidateatmospheric corrosion and metal runoff processes on copper andzinc used for roofing applications. Detailed studies have beenperformed to disclose the effect of various parameters on therunoff rate including: surface inclination and orientation,natural patination (age), patina composition, rain duration andvolume, rain pH, and length of dry periods inbetween rainevents. Annual and average corrosion rates and runoff rateshave been determined consecutively during urban field exposuresin Stockholm on naturally patinated copper and zinc of varyingage and patina composition. The corrosion rate was found todecrease with time, amounting to 6.7 g Cu/(m2.y) and 5.0 gZn/(m2.y) after 48 weeks of exposure, whereas the runoff ratewas relatively constant with time on a yearly basis, being 1.3g/(m2.y) and 3.1 g/(m2.y) for copper and zinc, respectively.The annual runoff rate was found to be significantly lower thanthe corresponding corrosion rate for both copper and zinc.Somewhat higher runoff rates of copper were determined fromnaturally green-patinated copper (&gt;40 years old, 2.0g/(m2.y)) compared to brown-patinated copper (1 year old). Themain reasons are specific environmental conditions combinedwith characteristics of the patina layer, which increase themagnitude of dissolved species flushed from the surface duringthe first flush volume of a rain event. No intrinsic effect ofpanel age on the runoff rate was seen for naturally patinatedzinc. However, differences in prevailing environmentalconditions during the initial exposure period and, hence,differences in formation rate and surface coverage of thecorrosion patina, resulted in variations in runoff rate. Thisinitial difference remained also during prolonged exposureperiods and was referred to as a memory effect. Model roof investigations and laboratory studies showedsurface orientation and inclination to have a detrimentaleffect on the runoff rate with high runoff rates from surfacesof low inclination from horizon and surfaces exposed towardsthe wind direction. Based on fieldexposures and literature data, a correlationwas established between the runoff rate and the prevailingSO2-concentration. The runoff rate increases with increasingSO2 level for exposure sites of similar annual precipitationquantities (500-1000 mm/y). A rain device, using artificialrain, was shown to successfully simulate outdoor rain events ofvarying intensity and pH and result in realistic runoff ratesof both copper and zinc. The device was used to monitor changesin metal concentration and quantity of runoff water duringindividual rain events. High metal concentrations are found inthe initial rain volume flushing the surface (first flush),which decreased to rather constant metal concentrations duringthe subsequent rain volume (steady-state). The magnitude offirst flush depends primarily on environmental conditions priorto a rain event and the characteristics of the corrosionpatina. The metal concentration in runoff water increases withrain acidity, decreases with rain intensity and increases withlength of the dry period preceding a rain event. A comparison between instantaneous corrosion rates,monitored by electrochemical impedance spectroscopy using a2-electrode set-up, and runoff rates during a continuous rainevent was performed for naturally patinated copper panels.Corrosion rates were found to be approximately 10 (brownishpatina) and 25 times (greenish patina) lower than correspondinginstantaneous runoff rates. A schematic description of the first flush and steady-stateregion of the runoff process was established. The magnitude ofthe concentration during first flush is primarily affected byprevailing environmental conditions prior to a rain event,while rain pH and intensity primarily affect the concentrationduring steady-state. <b>Key words:</b>atmospheric corrosion, corrosion rate, runoffrate, copper, zinc, field study, laboratory study, roof, firstflush, rain quantity, rain intensity, rain pH, dry and wetdeposition, corrosion and runoff process.

<p>An extensive investigation with parallel field andlaboratory exposures has been conducted to elucidateatmospheric corrosion and metal runoff processes on copper andzinc used for roofing applications. Detailed studies have beenperformed to disclose the effect of various parameters on therunoff rate including: surface inclination and orientation,natural patination (age), patina composition, rain duration andvolume, rain pH, and length of dry periods inbetween rainevents. Annual and average corrosion rates and runoff rateshave been determined consecutively during urban field exposuresin Stockholm on naturally patinated copper and zinc of varyingage and patina composition. The corrosion rate was found todecrease with time, amounting to 6.7 g Cu/(m2.y) and 5.0 gZn/(m2.y) after 48 weeks of exposure, whereas the runoff ratewas relatively constant with time on a yearly basis, being 1.3g/(m2.y) and 3.1 g/(m2.y) for copper and zinc, respectively.The annual runoff rate was found to be significantly lower thanthe corresponding corrosion rate for both copper and zinc.Somewhat higher runoff rates of copper were determined fromnaturally green-patinated copper (>40 years old, 2.0g/(m2.y)) compared to brown-patinated copper (1 year old). Themain reasons are specific environmental conditions combinedwith characteristics of the patina layer, which increase themagnitude of dissolved species flushed from the surface duringthe first flush volume of a rain event. No intrinsic effect ofpanel age on the runoff rate was seen for naturally patinatedzinc. However, differences in prevailing environmentalconditions during the initial exposure period and, hence,differences in formation rate and surface coverage of thecorrosion patina, resulted in variations in runoff rate. Thisinitial difference remained also during prolonged exposureperiods and was referred to as a memory effect.</p><p>Model roof investigations and laboratory studies showedsurface orientation and inclination to have a detrimentaleffect on the runoff rate with high runoff rates from surfacesof low inclination from horizon and surfaces exposed towardsthe wind direction.</p><p>Based on fieldexposures and literature data, a correlationwas established between the runoff rate and the prevailingSO2-concentration. The runoff rate increases with increasingSO2 level for exposure sites of similar annual precipitationquantities (500-1000 mm/y). A rain device, using artificialrain, was shown to successfully simulate outdoor rain events ofvarying intensity and pH and result in realistic runoff ratesof both copper and zinc. The device was used to monitor changesin metal concentration and quantity of runoff water duringindividual rain events. High metal concentrations are found inthe initial rain volume flushing the surface (first flush),which decreased to rather constant metal concentrations duringthe subsequent rain volume (steady-state). The magnitude offirst flush depends primarily on environmental conditions priorto a rain event and the characteristics of the corrosionpatina. The metal concentration in runoff water increases withrain acidity, decreases with rain intensity and increases withlength of the dry period preceding a rain event.</p><p>A comparison between instantaneous corrosion rates,monitored by electrochemical impedance spectroscopy using a2-electrode set-up, and runoff rates during a continuous rainevent was performed for naturally patinated copper panels.Corrosion rates were found to be approximately 10 (brownishpatina) and 25 times (greenish patina) lower than correspondinginstantaneous runoff rates.</p><p>A schematic description of the first flush and steady-stateregion of the runoff process was established. The magnitude ofthe concentration during first flush is primarily affected byprevailing environmental conditions prior to a rain event,while rain pH and intensity primarily affect the concentrationduring steady-state.</p><p><b>Key words:</b>atmospheric corrosion, corrosion rate, runoffrate, copper, zinc, field study, laboratory study, roof, firstflush, rain quantity, rain intensity, rain pH, dry and wetdeposition, corrosion and runoff process.</p>

<p>This licentiate study was initiated by copper, zinc and galvanized steel producers in Europe, who felt a need to assess runoff rates of copper and zinc from the pure metals and commercial products at marine exposure conditions. Their motive was the increasing concern in various European countries and the on-going risk assessments of copper and zinc within the European commission. Also the circumstance that available runoff rates so far, had been reported for mainly urban exposure conditions, rather than marine. A collaboration was therefore established with the French Corrosion Institute, which runs a marine test site in Brest, and a set of vital questions were formulated. Their answers are the essence of this licentiate study.</p><p>Based on the ISO corrosivity classification and one-year exposures, the marine atmosphere of Brest is fairly corrosive for zinc (class C3) and highly corrosive for copper (C4). Despite higher corrosivity classifications for both metals in Brest compared to the urban site of Stockholm, used as a reference site, nearly all runoff rates assessed for copper, zinc and their commercial products were lower in Brest compared to Stockholm. This was attributed to a higher surface wetting in Brest and concomitant higher removal rate of deposited chloride and sulphate species from the marine-exposed surfaces. The comparison shows that measured corrosion rates cannot be used to predict runoff rates, since different physicochemical processes govern corrosion and runoff respectively.</p><p>For copper, the runoff rate in Brest was approximately 1.1 g m^-2 yr^-1 with cuprite (Cu2O) as main patina constituent. During periods of very high chloride and sulphate deposition, paratacamite (Cu₂Cl(OH)₃) formed which increased the runoff rate to 1.5 g m^-2 yr^-1. For zinc, with hydrozincite (Zn₅(CO₃)2(OH)₆) as the main patina constituent, the runoff rate was relatively stable at 2.6 g m^-2 yr^-1 throughout the year, despite episodes of heavy chloride and sulphate deposition.</p><p>The application of organic coatings of varying thickness on artificially patinated copper or on different zinc-based products resulted in improved barrier properties and reduced runoff rates that seem highly dependent on thickness. The thickest organic coating (150 µm thick), applied on hot dipped galvanized steel, reduced the runoff rate by a factor of 100. No deterioration of organic coatings was observed during the one-year exposures. Alloying zinc-based products with aluminium resulted in surface areas enriched in aluminium and concomitant reduced zinc runoff rates.</p><p>The release rate and bioavailability of copper from different anti-fouling paints into artificial seawater was also investigated. It turned out that the release rate not only depends on the copper concentration in the paint, but also on paint matrix properties and other released metal constituents detected. Far from all copper was bioavailabe at the immediate release situation. In all, the results suggest the importance of assessing the ecotoxic response of anti-fouling paints not only by regarding the copper release, but rather through an integrated effect of all matrix constituents.</p>

This licentiate study was initiated by copper, zinc and galvanized steel producers in Europe, who felt a need to assess runoff rates of copper and zinc from the pure metals and commercial products at marine exposure conditions. Their motive was the increasing concern in various European countries and the on-going risk assessments of copper and zinc within the European commission. Also the circumstance that available runoff rates so far, had been reported for mainly urban exposure conditions, rather than marine. A collaboration was therefore established with the French Corrosion Institute, which runs a marine test site in Brest, and a set of vital questions were formulated. Their answers are the essence of this licentiate study. Based on the ISO corrosivity classification and one-year exposures, the marine atmosphere of Brest is fairly corrosive for zinc (class C3) and highly corrosive for copper (C4). Despite higher corrosivity classifications for both metals in Brest compared to the urban site of Stockholm, used as a reference site, nearly all runoff rates assessed for copper, zinc and their commercial products were lower in Brest compared to Stockholm. This was attributed to a higher surface wetting in Brest and concomitant higher removal rate of deposited chloride and sulphate species from the marine-exposed surfaces. The comparison shows that measured corrosion rates cannot be used to predict runoff rates, since different physicochemical processes govern corrosion and runoff respectively. For copper, the runoff rate in Brest was approximately 1.1 g m-2 yr-1 with cuprite (Cu2O) as main patina constituent. During periods of very high chloride and sulphate deposition, paratacamite (Cu2Cl(OH)3) formed which increased the runoff rate to 1.5 g m-2 yr-1. For zinc, with hydrozincite (Zn5(CO3)2(OH)6) as the main patina constituent, the runoff rate was relatively stable at 2.6 g m-2 yr-1 throughout the year, despite episodes of heavy chloride and sulphate deposition. The application of organic coatings of varying thickness on artificially patinated copper or on different zinc-based products resulted in improved barrier properties and reduced runoff rates that seem highly dependent on thickness. The thickest organic coating (150 µm thick), applied on hot dipped galvanized steel, reduced the runoff rate by a factor of 100. No deterioration of organic coatings was observed during the one-year exposures. Alloying zinc-based products with aluminium resulted in surface areas enriched in aluminium and concomitant reduced zinc runoff rates. The release rate and bioavailability of copper from different anti-fouling paints into artificial seawater was also investigated. It turned out that the release rate not only depends on the copper concentration in the paint, but also on paint matrix properties and other released metal constituents detected. Far from all copper was bioavailabe at the immediate release situation. In all, the results suggest the importance of assessing the ecotoxic response of anti-fouling paints not only by regarding the copper release, but rather through an integrated effect of all matrix constituents. / QC 20101126