title: Effect of substrate depth and rain-event history on the pollutant abatement of green roofs.
abstract: This study compares the effectiveness of two different thickness of green roof substrate with respect to nutrient and heavy metal retention and release. To understand and evaluate the long term behaviour of green roofs, substrate columns with the same structure and composition as the green roofs, were exposed in laboratory to artificial rain. The roofs act as a sink for C, N, P, zinc and copper for small rain events if the previous period was principally dry. Otherwise the roofs may behave as a source of pollutants, principally for carbon and phosphorus. Both field and column studies showed an important retention for Zn and Cu. The column showed, however, lower SS, DOC and metal concentrations in the percolate than could be observed in the field even if corrected for run-off. This is most probably due to the difference in exposition history and weathering processes.
authors.affiliation: University Paris-Est, LEESU, UMR-MA-102, Ecole des Ponts ParisTech, 6-8 Avenue Blaise Pascal, Cité Descartes, Champs-sur-Marne, 77455 Marne la Vallée cedex 2, France. Electronic address: martin.seidl@leesu.enpc.fr.
authors.forename: Martin
authors.initials: M
authors.lastname: Seidl
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Gromaire
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saad
authors.forename: Bernard
authors.initials: B
authors.lastname: De Gouvello
mesh_terms: D001673:Biodegradation, Environmental; D003247:Conservation of Natural Resources / Q000379:methods*; D052918:Environmental Restoration and Remediation / Q000295:instrumentation / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis; D011891:Rain
keywords: Columns experiments; Emission; Heavy metals; Nutrients; Retention; Vegetated roofs