In order to investigate effects of operation mode on the phosphorus removal and recovery performance of PAOs-biofilm, the continuous operating PAOs-biofilm reactor was carried out to recovery phosphorus from synthetic sewage wastewater with different operation modes. It showed that the operating modes resulted in significant differences of the environment for phosphorus uptake and release (phosphorus concentration in water). Under the “anaerobic-aerobic alternating” mode, the high phosphorus loading in aerobic phase strengthened the phosphorus uptake ability of the PAOs-biofilm, and the phosphorus recovery performance depended on the limitation of phosphorus uptake. In contrast, under the “aerobic-anaerobic alternating” mode, the high concentration of phosphorus in anaerobic phase depressed the phosphorus release ability of the PAOs-biofilm, which could be the main reason for the limited phosphorus recovery performance. Such differences in environment resulted from the operation modes led to different aerobic phosphorus uptake, anaerobic phosphorus release and carbon source utilization rate of biofilm. The average Prel/Cupt under “anaerobic-aerobic alternating mode” was 0.213 mmol P /mmol C, which was much higher than that of 0.046 mmol P/mmol C under “aerobic-anaerobic alternating” mode. In summary, the PAOs-biofilm showed higher efficiency in phosphorus removal under “anaerobic-aerobic alternating” mode, while it exhibited a more superior performance in phosphorus recovery under “aerobic-anaerobic alternating” mode, with phosphorus recovery liquid of 99.90 mg/L.

为了探究运行模式(即厌氧、好氧顺序不同)对聚磷生物膜磷去除与回收效果的影响, 采用相同的聚磷生物膜对模拟城市污水进行磷回收。经过连续运行生物膜反应器, 发现在不同运行模式下, 聚磷生物膜的吸磷和释磷环境(水体中磷浓度)有显著差异。在“厌氧–好氧交替”模式下, 好氧阶段的高磷负荷会强化生物膜的吸磷能力, 此时磷回收的效果取决于吸磷的限值; 而“好氧–厌氧交替”模式下, 厌氧阶段的高浓度磷会抑制生物膜释磷能力, 成为限制磷回收效果的主要原因。这种由运行模式带来的吸磷和释磷环境差异导致生物膜的好氧吸磷量、厌氧释磷量以及释磷时的碳源利用率不同, “厌氧–好氧交替”模式下生物膜的碳源利用效率为0.213 mmol P/mmol C, 远高于“好氧–厌氧交替”模式下的0.046 mmol P/mmol C。综合来看, “厌氧–好氧交替”模式下的聚磷生物膜磷在磷去除率和碳源利用率方面更具优势, 而“好氧–厌氧交替”模式下的磷回收效果更佳, 磷回收液浓度达到99.90 mg/L。