The food factory stopped production during the epidemic in early 2020. After the resumption of production in May, the sludge in the aeration tank expanded, the foam surged, and the ammonia nitrogen in the water seriously exceeded the standard. The aerobic system is 1,200 cubic meters and treats 1,000 cubic meters of sewage per day. Our technicians suggest that the foam should be removed with a defoamer first. After adding 300 kg of our aerobic bacteria, the water color gradually began to turn yellow on the third day, and the SV30 reached 35%. , The water quality improved significantly on the fifth day, and the effluent reached the standard.