Full-Scale Testing Postpones Total Nitrogen Reduction Expansion

摘要

The City of Rochester New Hampshire received notice that its next National Pollutant Discharge Elimination System permit will contain seasonal summer total nitrogen (TN) discharge requirements of 8 to 10 mg-N/L. To reduce TN discharges to the anticipated discharge levels, the City conducted an 8-month full-scale demonstration test operating under a low dissolved oxygen/simultaneous nitrification-denitrification (SND) mode to reduce TN discharges. Testing and subsequent process modeling showed the SND operating mode could achieve monthly effluent TN discharges below 8 mg-N/L without a plant expansion and without impacting sludge quality.