Sludge Digestion

Anaerobic sludge digestion is widely used to stabilize concentrated organic solids removed from settling tanks, biological filters and activated sludge plants. Sludge digestion renders the sludge suitable for reuse purposes such as land fill and garden mulch (local authority permitting). Sludge digestion tanks are normally covered with concrete or steel roof structures of different shape and structural design. Dome shaped covers are often used both in steel or concrete construction, steel covers can be fixed or floating. Floating covers in primary digestion tanks have a number of advantages. The more uniform gas pressure provides a high degree of operating safety and the maintained relationship between liquid level and mixing devices fitted on floating covers results in greater operating consistency.