Using pH and ORP to Optimize Phased Nitrfication-Denitrfication Operation
City of Bozeman Water Reclamation FacilityBozeman, Montana
The City of Bozeman, Montana (pop. 36,000) recently converted the operation of its complete mix activated sludge aeration basins to plug flow basins operating in a phased nitrification-denitrification mode. Operation in phased nitrification denitrification mode has reduced the plant’s effluent total nitrogen by 40% without sacrificing ammonia removal. Sludge volume index values also dropped slightly with this modification. Chlorine use for filament control and disinfection has dropped from 52 tons per year to 32 tons per year. The total capital cost for project implementation was $180,000. The process uses pH and ORP probes to control and optimize nitrogen removal efficiency. This case study shows that with PNDN:
• Ammonia removal goals can be met with appropriate process control and cycle times.
• Significant total nitrogen removal can be achieved with the process.
• Modest improvement in phosphorus removal may be observed.
• Bulking may be reduced significantly.
• ORP/pH control can be used to create repeatable and reliable nitrogen removal.
• The process is flexible and allows the operator to set cycle times and the ORP set point as needed to respond to plant conditions as needed. Source: WEFTEC 2009 Proceedings
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Posted: July 6th, 2010 | Filed under: <50K, Waste Water Treatment, Water Treatment | Tags: Environmental Impact, Phased Nitrfication-Denitrfication Operation | No Comments »