Siemens' ISBR system has allowed a California wastewater treatment facility to minimize solids wasting to less than 0.1 lbs of biological solids per lb of BOD treated.
Click here to enlarge imageThe SBR system uses a fill-and-draw, non-steady state activated sludge process. One or more reactor basins are filled with wastewater during a discrete time period and then operated in a batch treatment mode. The system accomplishes equalization, aeration and clarification in a timed sequence – all in a single reactor basin. In a conventional continuous flow process, multiple structures are required to obtain the same treatment objectives.
The Cannibal interchange bioreactor is at the heart of the ISBR process. The solids reduction process requires minimal aeration, and provides a non-aerobic environment. That environment selects for low-growth facultative bacteria and also stresses and conditions aerobic bacteria which, in turn, breaks down cells and increases biodegradability. The reactor's contents are interchanged back into the SBR process – into a non-aerobic cycle.
An option for secondary treatment and solids reduction, the ISBR system is suited for plants that have high solids handling costs, high energy costs and tight effluent requirements. It is also appropriate for applications where nitrification and denitrification are necessary.
System Benefits
The Omniflo ISBR system has an inherent biological nutrient removal (BNR) capability through the use of automated controls that provide optimum environments for each BNR reaction. It also produces a very high-quality effluent at varying flows and loadings with better control over micro-organisms. The small footprint system produces a sludge yield of 0.05 to 0.30 lbs of biological solids per lb of BOD per day and, compared to a typical SBR system, provides increased flexibility as well as significant power savings.