Microbiological studies of composted sewage sludge for agricultural usage [German]

摘要

Successful composting of sludges from waste water treatment plants and slaughterhouses is necessary to prevent environmental hazards. The effectiveness of sewage sludge treatment on the inactivation of salmonellae was therefore investigated. The study involved the seeding of salmonellae into three layers of compost heaps. In plant I, aeration was indirect by turning the heaps. In plant II, aeration was achieved by a perforated pipe system through which air was drawn. Disinfection was achieved in plant I, with the salmonellae not surviving for more than 28 days. In plant II, survival was longer with a range of 29 to 158.9 days. The daily rate of inactivation varied between 0.049 and 0.280 log.. The results therefore indicated that composting can result in the exclusion of pathogenic micro-organisms such as salmonellae. The systems that are ultimately specified depends on the EU-sewage sludge Guideline.