This lesson is a basic description of aerobic digestion. Topics presented include a general process overview discussion of a typical digester's components, factors influencing performance, operational controls, and biological considerations for successful operation. The lesson includes an instructor's guide and student workbook. The instructor's guide contains a description of the lesson, estimated presentation time, instructional materials list, suggested sequence of presentation, reading lists, objectives, lecture outline, narrative of the slide/tape program used with the lesson, and student worksheet (with answers). The student workbook contains plant flow diagrams, objectives, glossary, discussion of aerobic digestion, references, and worksheet. (JN)