基质冲击对ANAMMOX颗粒释放AHLs及颗粒特性的影响

从群体感应角度考察基质冲击对ANAMMOX颗粒特性的影响，以期为提高ANAMMOX颗粒抗基质冲击能力提供理论指导与借鉴.结果表明，24h 1500mg/L总氮冲击刺激颗粒AHLs释放量由4.3大幅增加至10.0，同时颗粒结合性胞外聚合物（B-EPS）过量释放（增加了107.3mg/g VSS），导致颗粒沉降性能下降（密度和沉速分别降低了53%和33%）.但基质浓度恢复至稳定期水平后，AHLs释放量逐渐恢复至稳定期水平，同时B-EPS产量和颗粒性状也逐渐恢复至稳定期水平，推测基质冲击导致AHLs释放量的变化进而引起B-EPS产量的变化.批次试验结果进一步证实了基质浓度显著影响AHLs释放量，B-EPS产量与AHLs释放量密切相关.总氮浓度为1000mg/L时，AHLs释放量高达11.7，导致B-EPS中的松散结合性EPS（LB-EPS）相比总氮浓度为200mg/L时增加了69mg/g VSS，颗粒沉降性能下降.然而紧密结合性EPS（TB-EPS）含量不受基质浓度影响，认为LB-EPS是决定颗粒沉降能力的关键因素.低浓度抑制剂可有效抑制高基质浓度引起的AHLs过量释放，使LB-EPS产量降低36%，颗粒沉降性能和活性得以提高.

Effects of substrate shock on AHL signals release of ANAMMOX granules and characteristics of granules

Effects of substrate shock on the characteristics of ANAMMOX granules were investigated from the perspective of quorum sensing with the final purpose of providing theoretical guidance and reference for improving the stability and settleability of ANAMMOX granules under substrate shock. The results showed that due to 24h 1500mg/L total nitrogen (TN) shock, the amount of AHLs released by ANAMMOX granules increased significantly from 4.3 to 10.0. At the same time, excessive release of bound extracellular polymeric substances (B-EPS) (increased by 107.3mg/g VSS) was observed, which led to the poor settling performance of granules (density and settling velocity reduced by 53% and 33%, respectively). However, after the TN concentration returned to the level in the stable period, the release amount of AHLs, B-EPS content and granules properties could also return gradually to the level in the stable period. It was inferred that substrate shock resulted in the change of release amount of AHLs, which caused the change of B-EPS production. The results of the batch test also confirmed that the substrate concentration affected the release of AHLs, significantly. Moreover, B-EPS production was closely related to the release amount of AHLs. When the TN concentration was 1000mg/L, the release amount of AHLs was up to 11.7, leading to excessive accumulation of loosely-bound EPS (LB-EPS) (increased by 69mg/g VSS) and poor settleability of granules comparing with 200mg/L TN concentration. In contrast, the tightly-bound EPS (TB-EPS) content was not affected by substrate concentration. Thus, the LB-EPS was considered the key factor for the deterioration of granule settleability. Low concentration inhibitor can effectively inhibit the excessive release of AHLs caused by high substrate concentration, resulting in 36% reduction in LB-EPS content and improvement of the settleability and activity of granules.