Method for phosphorus removal and recovery using organic carbon source of urban sewage

A method for phosphorus removal and recovery using an organic carbon source of urban sewage, by means of a biofilm reactor containing a phosphorus-accumulating biofilm, an aeration device arranged in the biofilm reactor and a recovery tank, the method comprising the following steps:

• (a) adding urban sewage to the biofilm reactor until the biofilm reactor is full;
• (b) stirring the urban sewage under anaerobic condition, so that phosphorus is released from the phosphorus-accumulating biofilm by utilizing an organic carbon source in the urban sewage;
• (c) discharging a portion of the urban sewage after being treated in step (b) into the recovery tank and storing as a recovery solution;
• (d) turning on the aeration device to perform an aerobic aeration treatment on the remaining portion of the urban sewage after being treated in step (b) in the biofilm reactor, such that phosphorus therein is taken up by the phosphorus-accumulating biofilm until the concentration of phosphorus meets the discharge standard;
• (e) turning off the aeration device, and discharging all the urban sewage during and after being treated in step (d);
• (f) recirculating the recovery solution to the biofilm reactor, starting a new cycle from step (a);
• and obtaining a phosphorus recovery solution of a plurality of phosphorus recovery solutions when the concentration of phosphorus in the recovery solution meets requirements for a phosphorus recovery process;
• wherein, steps (a)-(f) constitute an operation cycle, during which the urban sewage treated by the biofilm reactor in step (d) in each operation cycle is continuously discharged;
• and after a plurality of operation cycles, the plurality of phosphorus recovery solutions in which the concentration of phosphorus meets the requirements for a phosphorus recovery process are obtained;
• at which point a phosphorus concentration cycle is reached.