Disputas: Mesay Mulugeta Wolle

Prøveforelesning

Bedømmelseskomité

Professor Carlo Vandecasteele, University of Leuven, Dept. Chemische Ingenieurstechnieken, Belgium
Senior lecturer/PhD Jean Pettersson, Department of Physical and Analytical Chemistry, Uppsala University, Sweden
Professor Elsa Lundanes, Department of Chemistry, University of Oslo

Leder av disputas:  Professor Tyge Greibrokk

Veileder:  Professor Grethe Wibetoe, Department of Chemistry, UiO, Christian J. Engelsen, SINTEF Building and Infrastructure og Professor Rolf D. Vogt, Department of Chemistry, UiO

Sammendrag

Waste materials are recycled for various applications with the aims of conserving natural resources, minimizing the cost of their disposal and reducing their deposit in landfills. Thus, the recycling of construction and demolition wastes is increasing. The environmentally acceptable application of such materials necessitates evaluation of the emission of toxic constituents from the materials into soil and ground water. Such experimental studies require the use of efficient and robust analytical methods. The aim of the Ph. D. study was to develop operationally simple, fast and cost-effective analytical methodologies for the fractionation and speciation analyses of oxyanion-forming metals and metalloids, namely As, Cr, Mo, Sb, Se and V, released from recycled cement-based construction materials. The developed methods are:
• a dual mode of sample introduction, i.e. introducing gaseous hydrides along with sample aerosols, for the simultaneous determination of As, Cr, Mo, Sb and V using inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS),
• ion-exchange solid phase extraction (SPE) for the charge-based fractionation analysis of As, Cr, Mo, Sb, Se and V,
• multiple extraction for overcoming matrix interferences in the ion-exchange SPE of As, Cr, Mo, Sb, Se and V species,
• SPE for the redox speciation analysis of As, Sb and Se, and
• anion-exchange high performance liquid chromatography (HPLC) coupled with ICP-MS for the speciation analysis of the oxyanions of As, Cr, Mo, Sb, Se and V.
The successful use of the developed methods is demonstrated by evaluating the release of the target elements from cement mortar and concrete materials, and by characterizing the released elements according to their charge and distinct chemical forms.

Kontaktperson

For mer informasjon, kontakt Raul Boris Farina Briceno.