Using Biosolids As A Carbon Source for Denitrification

As wastewater treatment plants are being modified and upgraded to make biological nutrient removal more effective, there is often a need for supplemental carbon to assist in the biological reaction. Until recently a majority of treatment plant designs have been utilizing methanol as an external carbon source to drive denitrificaiton. New technology processes, exploit the opportunity to use carbon that is readily available in biosolids as an internal carbon source to drive denitrificaiton. This investigation focuses on using OpenCEL treated thickened waste activated sludge (TWAS) a method of internally providing a carbon source for denitrification. This study reports both on lab and fullscale studies using OpenCEL treated TWAS. When FP-treated TWAS was added in an ideal carbon-to-nitrogen (C:N) ratio, nitrate levels remained at baseline values at the same time reducing methanol consumption by 60%. Thus, the full-scale results document that FP-treated solids could replace an exogenous organic electron donor.