污泥转移SBR工艺中EPS对生物除磷的作用

摘要

采用新型强化生物除磷工艺——污泥转移SBR处理合成废水，探讨胞外聚合物（EPS）在工艺强化除磷过程中的作用。当污泥转移量为0、15%及30%时，污泥中的EPS含量分别为（108.14±9.68）mg·(g MLSS)−1、（128.17±1.45）mg·(g MLSS)−1和（123.35±22.98）mg·(g MLSS)−1；工艺的除磷率分别为82.14%±0.85%、96.35%±1.25%及98.99%±0.98%，反应末端 EPS 中 TP 含量占污泥中 TP 的比重分别为27.9%±2.55%、57.23%±2.33%和63.88%±2.87%。此外，污泥中 EPS 在该工艺的好氧吸磷过程中吸磷量分别为（2.04±0.32） mg·(g MLSS)−1、（5.90±0.38）mg·(g MLSS)−1和（6.00±0.52）mg·(g MLSS)−1，在污泥吸磷量中的贡献率均达到90%以上。研究结果表明：污泥转移 SBR 工艺中随着污泥转移量的增大有利于提高 EPS 中的磷含量，从而提升了工艺的除磷性能，EPS 在该工艺的吸磷过程中起主要作用。但污泥转移对污泥中 EPS 含量影响不显著。%An updated enhanced biological phosphorus removal-sludge shifting SBR process was used for the treatment of synthetic wastewater. The role of extracellular polymeric substances (EPS) in the enhanced phosphorus removal process was investigated. As the sludge reflux ratios (characterized by sludge shifting volumes) was set as 0 , 15% and 30%, the content of EPS in the sludge was (108.14±9.68) mg·(g MLSS)−1, (128.17±1.45) mg·(g MLSS)−1 and (123.35±22.98) mg·(g MLSS)−1, respectively. The total phosphorus removal efficiency in sludge (by sludge adsorption) was 82.14%±0.85%, 96.35%±1.25% and 98.99%±0.98%, respectively. Accordingly, the TP concentrations in the EPS at the end of the process accounted for 27.9%±2.55%, 57.23%±2.33% and 63.88%±2.87% of the TP concentrations in the sludge, respectively. In addition, the adsorption of phosphorus by EPS was (2.04±0.32) mg·(g MLSS)−1, (5.90±0.38) mg·(g MLSS)−1 and (6.00±0.52) mg·(g MLSS)−1, respectively, during the aerobic phosphorus adsorption process. In all the above cases, the EPS has contributed more than 90% of the phosphorus adsorption capacity of the sludge. The results indicated that in sludge shifting SBR process, the increase of the amount of sludge shifting improved phosphorus content in the EPS and corresponding phosphorus removal, showing that EPS played a major role in the phosphorus removal process. But sludge shifting had almost no impact on EPS content in the sludge.