Case Study: TETRA® Methanol Dosing Technology Helps Denitrification System Pass Rigorous Performance TestSource: Severn Trent Services
In 2007, Greenville, S.C.-based Western Carolina Regional Sewer Authority (WCRSA) conducted a rigorous performance test on a new tertiary treatment technology to assess its ability to effectively remove nitrate-nitrogen (NO3-N) without using excess amounts of methanol at its Lower Reedy Wastewater Treatment Plant (WWTP).
Precise feeding of methanol for tertiary denitrification poses quite a challenge for most tertiary systems – particularly during flow variations. Dosage rates that are too small can lead to excess NO3-N concentrations. If methanol is overfed, it may result in elevated effluent biochemical oxygen demand (BOD) concentrations. For every extra part per million (ppm) of methanol overfeed, the BOD may increase by 1.5 ppm.
Deep bed denitrification filters – the combination of denitrification and suspended solids (SS) removal in a deep bed filter process – have proven to be a highly effective technology for meeting effluent standards. The TETRA® DeepBed™ Denite® System from Severn Trent Services is a fixed-film biological denitrification process that also serves as a deep bed filtration system capable of removing SS to meet stringent final effluent requirements. The system integrates with other treatment processes to provide effective total nitrogen (TN) and phosphorous removal.