[Cultivation and enrichment of denitrifying phosphorus removal bacteria (DPB) in denitrifying biological nutrient...

The cultivation of the denitrifying phosphorus removal bacteria (DPB) in biological nutrient removal system will directly affect the removal efficiency of the nutrients in wastewater such as nitrogen and phosphorus, and the stability of the process. For this reason, a new BNR process, which is called double-sludge denitrifying-nitrogen and phosphorus removal process, was designed. In order to create a good anaerobic/anoxic alternating environment for DPB, gradual transition of training methods were used to make DPB natural selection, and then finally, screened the dominated DPB bacteria. The results indicated that the anaerobic/aerobic (A/O) operation mode can induce induction of PAOs rapidly by 15 days intermittent aeration. The proportion of DPB/PAOs in the reactor was aggrandized in the second phase (about 25 days' inducement) by reducing the aeration time in aerobic phase gradually and adding nitrate in anoxic phase, which is called anaerobic/aerobic/anoxic (A/O/A) mode; finally, the strictly alternating environmental anaerobic/anoxic conditions for DPB were used to induce and enrich the target DPB bacteria for 19 days by a gradual transition of enrichment culture. The successful domestication and cultivation of DPB provides a new method to remove nitrogen and phosphorus efficiently and steadily in municipal wastewater.