Reactivation and Nitrogen Removal Performance of Idle Anammox Sludge Enhanced by Rape Straw Biochar
Low reactivation efficiency of idle anaerobic ammonia oxidation (anammox) sludge hinders its reapplication. To address this issue, rape straw biochar (RSB) was added in the reactivation process of idle anammox sludge, and its effects on the nitrogen transformation and sludge characteristics were investigated, and the mechanism of RSB to enhance the reactivation performance was explored. Results indicated that adding 5 g/L RSB for 35 days successfully reactivated anammox sludge that had been idle for 270 days. The reactivation time was reduced by 34% compared to the control without RSB. During the stable operation period, the average TN removal efficiency reached 90.6%, and the sludge exhibited higher activity. After completion of reactivation, the specific surface area, total pore volume, and average pore diameter of RSB decreased by 59.4%, 66.9%, and 55.2%, respectively, compared with that before reactivation, and the carbon–oxygen functional groups also changed. RSB not only provided a habitat for the enriched growth of nitrogen transforming functional flora but also possessed the potential to supply sufficient electron donors and acceptors for the nitrogen transforming process, which promoted the synergistic removal of nitrate by denitrification, resulting in an effective enhancement of reactivation efficiency and nitrogen removal performance. The addition of RSB provides a novel strategy to enhance the reactivation efficiency of idle anammox sludge, which is of positive significance in promoting its efficient reuse and stable operation.
危险品化学品经营许可证（带存储）