In summer, elevated wastewater temperatures cause microbial oxygen consumption to surge and make microbial communities prone to aging, frequently leading to problems such as ammonia nitrogen exceedance, total phosphorus exceedance, sludge bulking, and floating sludge and foam. To address these challenges, dissolved oxygen (DO) should be controlled on a zone-by-zone basis — raising DO in the aerobic stage during high-temperature periods while strictly maintaining low DO conditions in the anaerobic and anoxic zones. The MLSS in biological tanks should be lowered, sludge age moderately extended, and sludge discharge frequency increased to prevent and control sludge bulking and floating sludge. Carbon sources should be supplemented as needed, with PAC dosed to assist phosphorus removal when necessary. Aeration and mixing equipment should be inspected on a regular basis, and microbial inoculants can also be dosed to stabilize effluent quality. In addition, all types of foam should be treated promptly, influent loads should be balanced, and proper lightning protection and waterproofing measures should be implemented for equipment to prevent water quality anomalies.
