Making Waste Biosolids a Sustainable Organic Electron Donor for Denitrification Using Focused Pulsed Technology

As modern wastewater treatment plants are being upgraded to make biological nutrient removal more effective, the need for supplemental electron donors to drive these reactions is increasing, as are the costs of the external organic donors. The focus of this study was to analyze the application of using thickened waste activated sludge (TWAS) that was treated by using OpenCEL's Focused Pulsed (FP) technology as aninternallyproduced carbon source to drive denitrification. FP treatment provides two significant benefits to the biological nutrient removal process: 1) The economic savings of replacing an external organic donor with an internal source; and 2) alleviating the safety risks that plant personnel take when handling traditional external sources, particularly methanol. When FP-treated TWAS was added to obtain an ideal carbon-to-nitrogen (C:N) ratio, nitrate was completely reduced at the same rateas when methanol was used for the external organic electron donor. Thus, the full-scale results document that FPtreated solids could replace an exogenous organic electron donor. On-going work is focused on modeling the benefits of using FP treated TWAS, so that individual wastewater treatment plant characteristics can be used to determine the effects of FP-treated TWAS without needing to carry out a full-scale OpenCEL test.