Kaja Orupõld received her PhD at the University of Tartu, Estonia in environmental chemistry. She has worked as a lecture and a researcher at the University of Tartu, Estonia, in short term as a visiting researcher at the Lund University, Sweden. Presently, Kaja Orupõld is associate professor in environmental chemistry and ecotoxicology. She runs also the laboratory of Bio-and Environmental Chemistry at the Chair of Environmental Protection and Landscape Management of Estonian University of Life Sciences. Main research interests include anaerobic digestion of organic wastes, characterization of compost and waste for stability as well as mobility and bioavailability of hazardous substances in the environment.