Biological Aerated Filter | BAF Wastewater Treatment Filter

Working Principle Wastewater flows upward or downward through the filter media bed. Microorganisms attach to the surface of filter media and form biofilm. The bottom aeration system continuously supplies oxygen. Aerobic microbes decompose organic pollutants in wastewater, converting BOD, COD and ammonia nitrogen into CO₂, water and nitrogen gas to realize nitrification and nitrogen removal. The filter bed physically traps suspended particles simultaneously. After a period of operation, sludge accumulates inside the filter layer. The system activates air-water combined backwashing to strip aging biofilm and trapped sludge, restoring the treatment capacity of BAF. Aerobic and anoxic micro-environments coexist inside the reactor, enabling organic pollutant degradation and simultaneous nitrification & denitrification in one unit. Application Fields Municipal wastewater treatment: New construction & upgrade of urban sewage plants to reach Grade 1A discharge standard Industrial wastewater treatment: Biochemical treatment for food processing, textile printing, chemical and pharmaceutical wastewater Reclaimed water reuse project: Advanced wastewater treatment to produce recycled water for irrigation and circulating cooling water Rural decentralized sewage: Small village sewage treatment stations with small footprint and simple maintenance Landfill leachate treatment: Nitrogen removal and organic pollutant degradation for high-strength leachate River & lake remediation: Pretreatment for slightly polluted raw water to reduce water contaminants