Advanced Treatment of Secondary Effluent by Dissolved Air Flotation-Aerobic Filters Processes

The grouping technology of dissolved air flotation and aerobic filters are optimal to wastewater advanced treatment.Tests of improving secondary effluent by dissolved air flotation-aerobic filter's process are studied.The results indicate that the flotation-aerobic filters process can adapt well to different influent concentration, including high, middle and low concentration.The average removal rates of colority, COD, ammonia nitrogen, total phosphor and turbidity by flotation-aerobic filter's processes are 64.8%, 47.0%, 80%, 83%, and 77.8% respectively.The effluent reaches the Water Quality Standard for Urban miscellaneous Water Consumption (GB/T 18920—2002) and Urban Wastewater discharge standards (GB/T 18918—2002) when the influent is middle or low concentration.The UV₂₅₄ and bacteria are removed well too, and the average removal rates are 45.7% and 62.5% respectively.In the end, the results show that the flotation process plays a key role in aspect of removing organics, turbidity, total phosphor and UV₂₅₄, and the aerobic filters decrease the ammonia nitrogen concentration largely.On the basis of the flotation process, much turbidity and organics can be removed.