Abstract: Disclosed are an integrated dual circulation oxidization ditch apparatus for municipal wastewater and a treatment method. The apparatus comprises an anaerobic zone, an anoxic zone, an aerobic zone and a secondary sedimentation tank communicated in sequence. The anoxic zone comprises a first anoxic zone and a second anoxic zone. The aerobic zone comprises a first aerobic zone and a second aerobic zone, and a reflux pump is arranged between the anoxic zone and the aerobic zone. The anaerobic zone, the anoxic zone and the aerobic zone are internally provided with submersible mixers. Both the anoxic zone and the aerobic zone are internally provided with partition walls and guide walls, thereby forming circulation in each zone.

Abstract: The invention discloses a method for degrading phenol in industrial wastewater by a dual-frequency composite ultrasound, which belongs to the technical field of phenol degradation. The method adopts the dual-frequency composite ultrasound to perform ultrasonic treatment to a phenol solution to be degraded for 10-30 minutes. Degradation rate of phenol by the dual-frequency composite ultrasound can reach 83.74%, which is 45.23% and 51.11% higher than the degradation rates of a probe-type ultrasound alone and a tank-type ultrasound alone. Therefore, it can be clearly seen that the degradation effect of dual-frequency composite ultrasonic synergistic degradation of phenol in water is ideal.