A sludge ozonation process with lab-scale anaerobic/oxic (A/O) system was used to investigate the utilization of the ozonized sludge (OS) supernatant as extra carbon source for denitrification. The optimal ozone dose for the sludge ozonation was 0.2 gO3/gSS. The concentrations of SCOD, BOD, NH3-N and TN in the supernatant increased respectively at this ozone dose. In the meantime, the sludge was significantly reduced. The OS supernatant had negative effect on nitrification because of low pH and alkalinity. After alkalinity adjustment, the A/O with the OS supernatant as the extra carbon source achieved a nitrogen removal rate of 78%, which was very close to the control experiment using glucose (79%).
Bibliographical noteFunding Information:
The authors gratefully acknowledge the financial support of the Major Sci-Tec Projects on Water Pollution Control and Management Foundation of China (2009ZX07529-007) and Beijing Natural Science Foundation (8112021); Thanks are due to Kikuchi ECO-Earth Co. Ltd., Tokyo, Japan for the providing of the micro-bubble generator, and we thank Mr. Takashige Kikuchi for his support to our study.
- Low Carbon Source
- Nitrogen Removal
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry