During the drying process, the ejection shafts swirl the sewage sludge into a constant cloud and the 572°F (300°C) hot air circulates around, acting on all the sludge material simultaneously. The sewage sludge is completely sanitized by the high temperature. Microbiological testing even confirm extensive sterilization of the dried sewage sludge.
Pathogens which exist in the sewage sludge such as viruses, bacterial endotoxins, fungi, protozoa and worms, are completely destroyed by the drying procedure. During subsequent use as a fertilizer, there is no risk that pathogens can re-enter the human cycle.
Any health risk for humans coming into contact with sewage sludge is drastically reduced through sanitization.