The internship will take place at the Laboratoire Eau Environnement et Systèmes Urbains (LEESU), École nationale des ponts et chaussées, IP Paris (avenue Blaise Pascal, Champs-sur-Marne) and at the Maison des Sciences de l’Environnement (Université Paris-Est Créteil, rue Pasteur Valléry Radot, 94000 Créteil).

Context

Biocides are increasingly added to paints, renders and other building materials to protect them against fungi, algae, moss and insects such as termites (ANSES, 2019; Paijens et al., 2020a). These biocides are washed off in building runoff and discharged to soil or to stormwater management systems, from where they reach the environment with a potentially negative impact on aquatic and terrestrial ecosystems (Kresmann et al., 2018; Paijens et al., 2020a). The spread of source-control stormwater management, which aims to limit the volumes discharged to sewer networks, raises concerns about the fate of biocides in the soil of infiltration devices and in groundwater. Because most biocides are hydrophilic, they are not expected to be strongly retained by soil, unlike the micropollutants usually studied in runoff such as metals and polycyclic aromatic hydrocarbons (Tedoldi et al., 2016).

The internship is part of a PhD project at LEESU on biocide emissions from building façades and their fate in urban runoff and soils. The thesis has already completed emission and soil transport modelling; the internship will produce field and laboratory data to constrain them. It is also linked to the OPUR research programme, the Île-de-France urban hydrology observatory (https://www.leesu.fr/opur/), funded by local authorities in Île-de-France.

Objectives and methodology

The internship aims to measure biocide emissions from building façades and to study their transport in soil. It has two parts.

Part 1. Façade sampling

• Collection of runoff samples from building façades by artificial rain
• Extraction of the samples and analysis by liquid chromatography coupled with tandem mass spectrometry (LCMS/MS)

Part 2. Soil column experiments on biocide transport and degradation in soil

• Analyse of leachate and soil samples over time to follow biocide breakthrough and degradation

Reporting

• Writing a report

M1 or M2 in environmental sciences, environmental chemistry or a related field, with an interest in field and laboratory experimental work. Laboratory experience (sample preparation, chromatography) is an advantage.