The Disputation will be live streamed for everyone else.
The livestream will be activated 15 minutes before the Defense starts.
Trial lecture
March 7th, 10:15 AM, Auditorium 3, Chemistry building
Trial lecture title: "Production of Molybdenum-99 (Mo-99) for pharmaceutical purposes"
Kreeringssammendrag/Conferral summary
Doktorgradskandidaten undersøkte spesiering av krom og reduksjonsmekanismene til Cr(VI) i sure nitrofosfatløsninger med høyt saltinnhold for å bedre forstå spesiets oppførsel, mobilitet og miljøpåvirkning. Denne kunnskapen er avgjørende for å optimalisere separasjon av krom fra slike komplekse løsninger og forbedre gjenvinningsprosesser for krom. I tillegg evaluerer studien ulike ekstraksjonssystemer for effektiv Cr(VI)-separasjon og utforsker bruken av radioaktive sporstoffer for å forbedre hydrometallurgiske applikasjoner.
Main research findings
Phosphorus is essential for life and a key ingredient in the fertilizers that support global food production. However, as high-quality phosphorus sources become scarce, industries are turning to alternative materials that often contain unwanted impurities. This research investigates the removal and recovery of such impurities—especially the harmful form of chromium known as Cr(VI)—from acidic nitro-phosphate solutions. Under these harsh conditions, we found that Cr(VI) is unstable and converts to Cr(III), a much less toxic form that can even act as a nutrient. To better understand this process, we investigated the key factors influencing its reduction.
In addition, we explored various extraction methods and discovered that the extraction agent Cyanex 923 works particularly well for removing and recovering Cr(VI). We also produced radioactive tracers of lead (Pb) and arsenic (As) to further refine our process. Overall, this research contributes to a cleaner and more sustainable fertilizer production by turning a toxic challenge into an opportunity for resource recovery.
Candidate contact information
E-post: deniz.avsar@kjemi.uio.no
Phone: +47 967 47 183
Adjudication committee
Professor Kerstin Forsberg
Royal Institute of Technology, Sweden
Professor Teodora Retagan Vollmer
Chalmers University of Technology, Sweden
Professor Harald Johan Walderhaug
Department of Chemistry, University of Oslo, Norway
Supervisors
Professor Jon Petter Court Omtvedt
Department of Chemistry, University of Oslo, Norway
Senior advisor Dag Øistein Eriksen
Department of Chemistry, University of Oslo, Norway
Chair of defence
Professor Ola Nilsen
Department of Chemistry, University of Oslo, Norway