An apparatus for the anaerobic digestion of solid waste is disclosed. The apparatus includes a pre-digestion treatment chamber and an anaerobic digester chamber coupled to the pre-digestion treatment chamber. A liquid suspension of solid waste is pretreated under aerobic conditions by heating to a desired pre-digestion temperature. One or more chemical or biological additives are added to the suspension of solid waste to improve the anaerobic digestibility of the solid waste. This may include enzymes to destruct poorly digestible solids and/or materials to provide a desired C:N ratio in the solid waste. The apparatus may include mixers, heaters, chemical or biological additives as needed, various sensors and probes, and a control system to monitor and control the anaerobic digestion process and maintain microbial health of the digester.