Linking micro-aggregation to sequestration of organic pollutants in soil

Aggregation processes of (organo)mineral associations are assumed to be key processes for the formation and functioning of biogeochemical interfaces in soil. However, a direct link between the forces which induce aggregation and aggregate functioning is still missing. Our hypothesis is that interparticle forces control the diffusion of organic substances within aggregates by shaping the porosity, structure and stability of aggregates. We will analyze aggregates, which we synthesize from different primary particles (goethite, koalinite) using different methods to induce aggregate formation (increase of ionic strength, addition of polyvalent cations, addition of organic polyelectrolytes). Interparticle forces within the aggregates will be calculated based on dynamic light scattering (DLS) and the heat of aggregation (titration calorimetry). The calculations will be validated exemplarily by AFM measurements. In addition we will characterize the porosity, the structure and the stability of the artificial aggregates as well as the particle fraction < 250 nm of soils and artificial soil materials of the SPP 1315 central experiment. Results will be related to the diffusion of the pollutants into the aggregates, derived from sorption/desorption experiments and nanoSIMS analyses.

Ansprechpartner: Krüger J
Tel: 0761/203-3624
Email: jaane.krueger@bodenkunde.uni-freiburg.de

Projektbeginn: 01.12.2010
Projektende: 30.11.2013

Lang F, Kaupenjohann M (TU Berlin), von Klitzing R (TU Berlin)

Albert-Ludwigs-Universität Freiburg
Professur für Bodenökologie
Prof. Dr. Lang
Bertoldstr. 17
79098 Freiburg i. Br.

Telefon: +49 761 203 3625
Fax: +49 761 203 3618
Email: fritzi.lang@bodenkunde.uni-freiburg.de
http://www.bodenkunde.uni-freiburg.de

• Jaane Krüger

Jan Siemens (Uni Bonn), Jörg Bachmann (Uni Hannover), Martin Gerzabek (Boku Wien), Ingrid Kögel-Knabner (TU München), Gabriele Schaumann (Uni Koblen), Detlef Schenke (JKI Berlin)

• DFG - SPP, DFG