31.12.07 - Oleaginous Plant Seeds and Seed By-Products for Water Treatment. Thèse EPFL, n° 3572 (2006). Dir.: Prof. I. Marison

"For an internationally acclaimed study on water treatment with important implications for sustainable development and potable water resources"

Oleaginous Plant Seeds and Seed By-Products for Water Treatment.

This thesis consists of a systematic study to investigate the various possible applications of oleaginous seeds and seed by-products for water treatment, with rapeseed (/Brassica napus/) used as model species. Three main by-products of oilseeds were studied: (i) oil-bodies (OB), the organelles of oil storage in plant seeds, which consist of oil core microcapsules (» 1 mm diameter) surrounded by a lipo-proteinaceous membrane, (ii) press-cake (PC), the solid residue resulting after seed pressing for oil extraction, composed of fibres, proteins, membrane lipids and residual oil, and (iii) seed husks.

Oil-bodies were shown to have remarkable flocculation activity on silica or clay laden water, and thus represent a novel type of biological flocculant. Furthermore it was demonstrated that OB and PC constitute biosorbents for hydrophobic organic pollutants (HOP). The sorption mechanism, absorption, makes PC and OB particularly suited for the treatment of highly laden effluents and hydrophobic compounds. Finally the sorption of metal ions on PC and husks was investigated, showing very interesting sorption properties with complex adsorption mechanisms involving chemisorption and ion exchange.

The results of this thesis demonstrate that oleaginous seed materials exhibit versatile properties for developing novel and sustainable water treatment technologies.