A food factory in Anqiu specializes in fried foods (fried eggplant boxes, small crispy pork, etc.). Its production wastewater contains pollutants such as broken leaves, minced meat, starch, protein, and fat, and has the characteristics of good biodegradability and few toxic and harmful substances. Considering the working conditions of large water quality fluctuations and oil- and residue-containing wastewater, this scheme adopts the main process of "pretreatment + biochemical + sedimentation": first, grease and suspended solids are removed by screens, oil separation, and air flotation; then organic matter is biochemically degraded by anaerobic + contact oxidation; finally, the effluent meets the Grade III standard of the Integrated Wastewater Discharge Standard (GB 8978-1996), with COD reduced from about 3000 mg/L to below 432 mg/L.
