We would like to congratulate Dr.-Ing. Christian Fortenbacher on his doctorate. On July 19, 2022, Mr. Fortenbacher successfully defended his doctoral thesis entitled Anaerobic Stabilization of Screenings to Improve Energy Efficiency and Reduce_{CO2 Emissions} at Wastewater Treatment Plants. The examination committee consisted of Prof. Dr.-Ing. Franz-Bernd Frechen (Uni Kassel, first examiner), Prof. Dr.-Ing. Johannes Müller-Schaper (Uni Kassel, honorary professor) and Prof. Dr.-Ing. Tobias Morck (Uni Kassel) under the chairmanship of Prof. Dr. Matthias Gaßmann (Department of Hydrology and Material Balance, Uni Kassel).