The requirements for landfills have increased dramatically over the years. New environmental laws often entail additional costs for landfill operators; deposition criteria and technical requirements for landfills must comply to the Landfill Ordinance while state-of-the-art technology has to be used. This Thesis investigates strategies and processes for the biological activation of mass-waste landfills, according to the requirements of § 47 of the 2008 Landfill Ordinance. At first, the legal framework for landfills with biodegradable waste is explained. Subsequently, an overview of the generation, composition and energy content of landfill gas is given. The middle part of the Thesis discusses different strategies and procedures - some of which are already used in practice - concerning the biological activation of mass-waste landfills by intensifying anaerobic and aerobic degradation. Finally, a theoretical concept of a complete after care treatment system is presented, designed for the mass-waste landfill Frohnleiten, followed by a description of the procedures to be implemented at this landfill. Among others, an insight into the site and the landfilled waste is given.