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

Abstract

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.