Denitrification of Secondary Wastewater Using Sawdust

This contribution is devoted to the use of sawdust as materials to improve the efficiency of removing nitrate from the secondary wastewater. Sawdust, a relativery abundant and inexpensive material is being investigated as a porous treatment media to enhance removal of contaminants from wastewater. Successful nitrate removal from secondary wastewater has been demonstrated in a laboratory experiment using columns filled with porous soil material and sawdust and/or bamboo chip served as an organic carbon source. While the availability of organic carbon is one of the most important factors that affects denitrifying activity in soil. A mathematical solute transport model was developed to predict the nitrate degradation processes through a natural filter. The model computes changes in concentration over time caused by the processes of advection, dispersion and biological reactions. Results from a laboratory soil-sawdust and soil-bamboo chip columns experiments were used to verify the simulation results of the model. This study demonstrated that denitrification using sawdust as a carbon source can effectively remove nitrate from secondary wastewater when the carbon source is limiting in the influent secondary wastewater or groundwater.