Proceedings

This paper presents the process of autoheated thermophilic aerobic digestion (ATAD), a sludge treatment method for
achieving both effective sludge disinfection and a high degree of stabilization for returning sludge into the natural cycle. The
paper explains the principles of the ATAD process and presents performance data from existing ATAD facilities. Recent
investigations presented in the paper focus especially on the disinfection superiority of the ATAD process. The superior
disinfection of sludge treated by ATAD results in an odour-less biosolids product and prevents re-growth of pathogenic micro
organisms after application in agriculture. The paper presents microbiological analysis data from different ATAD plants in
Europe proving the superior disinfection quality of the process. Furthermore, microscopic photographs are presented
demonstrating the change in microbiological life when passing through the process.
KEY WORDS
ATAD, digestion, biosolids, sewage sludge, stabilization, disinfection, PFRP, Class A