I am a university professor in Geochemistry and Waste at UAM, where I teach approx. 180 h/year, supervise around 3 final degree theses annually, and serve as a jury member for about 10 each year. I also lead a European research project and an innovative teaching project, co-supervise a PhD thesis focused on the revalorization of construction and demolition waste, and actively participate in a national research project and two research contracts. My research experience spans three international groups across different countries. At the Department of Geology & Geochemistry in Spain (UAM, 2008-13), I researched the diffusion of leachate pollutants through geological materials and identified the most effective characteristics of geomaterials as natural barriers to prevent pollutant release. In Belgium, at the Department of Chemistry (KUL, 2014-18), I focused on the recovery of critical metals from waste using environmentally friendly extraction and leaching methods. I developed a unique process to recover rare earth elements with green solvents, avoiding nitrate-polluting leachates and reducing chemical consumption. Later, in the UK at the Department of Civil & Structural Engineering (TUOS, 2018-20), I developed recycled landfill barriers made from mixtures of rejected fine aggregates and natural clays. These barriers were designed to have low permeability and a low risk of cracking, capable of withstanding environmental conditions for up to 100 years.