Enhancement of Integrated Waste Activated Sludge Fermentation and Denitritation by Addition of Sodium Dodecyl Sulfate

Integrated waste activated sludge fermentation and denitritation (WASFD) is an efficient energy‐saving approach to treat wastewater and sludge at the same time. This study aimed at simultaneously promoting WASFD by adding sodium dodecyl sulfate (SDS). The batch‐mode tests showed that total volatile fatty acids (consisting of VFAs consumed for denitritation and VFAs observed) increased significantly at SDS dosages of 0.02–0.1 g/g dry sludge at room temperature. After 12 h, the released ammonium nitrogen reached the peak value at 0.1 g/g SDS, and decreased by 75.1% at 0.02 g/g SDS. Released phosphorus decreased by 63.1% at 0.02 g/g SDS compared to the peak value at 0.15 g/g SDS. Further investigation showed that the denitritation rate was enhanced at 0.02–0.05 g/g SDS. From the above, a suitable SDS dosage of 0.02 g/g is beneficial for WASFD with a relatively minor undesirable nutrient release from sludge fermentation.