Diffusion Of Chemicals From The Surface Of Pipe Materials To Water In Hydrodynamic Conditions: Applications To Domestic Drinking Water Installations

Domestic plumbing installations inside buildings could be a source of deterioration of drinking water quality. Organic materials in contact with drinking water could introduce organoleptic properties changes due to the diffusion of organic compounds from the pipe surface to the drinking water. Therefore, to limit the presence of organic substances in drinking water, some European countries implement regulations based on migration tests carried out in static condition. In France an "Attestation of Sanitary Conformity" (ASC) has been created. Indeed, materials in contact with water are evaluated to check the accordance with specific migration limits. However, despite the ASC, some materials release chemical compounds in the domestic networks and some organoleptic problems persist in operating conditions. The objective of this study is to determine a relationship between the amount of compounds migrating to tap water and the operating parameters such as temperature, flow rate and geometry of the network. Different organic materials were experimentally tested in terms of chemical release in water in dynamic pilot units. Transfer kinetic curves of organic micropollutants were determined in various operating conditions. Models of mass transfer in solids were applied and diffusion coefficients were obtained and compared to those found in literature. The innovative character of the study is to develop an experimental and numerical approach to estimate organic pollutant concentration present in water networks taking into account the influence of real conditions.