The research field is mainly characterization of waste, environmental effects of waste treatment and disposal facilities, and mitigation of landfill gas emissions. Has worked intensively on methane oxidation as a landfill gas mitigation process and has forwarded the process through several laboratory projects into a full-scale mitigation technology. Also extensive research in releases and fate of organic substances from waste materials during handling and disposal. Collaborative activities have been significant with more than 25 institutions including a range of universities around the world as well as industrial and consulting companies, public authorities and organizations. Served in committees and worked with a range of organizations (e.g. Danish Competence Center for Waste/DAKOFA, ISWA and IWWG). Is m ember of Executive Programme Committee for the Sardinia Solid Waste Management and Landfill Symposium since 2010. More than 100 ISI publications, several with national and international co-authors, more than 4300 citations, H-index=30. Supervisor/co-supervisor for 12 PhD-projects and more than 45 master thesis students.