BAF-SCAD for advanced wastewater nitrogen removal

This paper used a novel technology, BAF-SCAD, for the advanced nitrogen removal of wastewater after con. BAF stood for biological aerated filter and SCAD meant sulfur-ceramic autotrophic denitrification. The experimental results show that the BAF-SCAD system was successfully started after 2.5 months´ starting up. With a NaHCO₃ dosage of 1 g/L, the BAF-SCAD system effectively removed the pollutants. Excellent nitrogen removal was achieved by nitrification in the BAF and denitrification in the SCAD. When the concentrations of NH₃-N, NO₃-N, TN in the influent were 10-20mg/L, 8-16mg/L, 25-30mg/L respectively, the concentrations of NH₃-N and NO₃-N in the effluent were below lmg/L and the TN was 1-3 mg/L. The removal efficiency of NH₃-N was above 95% and the removal efficiency of TN was above 90%. The COD removal efficiency of BAF was between 20%-30% while COD in the effluent of SCAD increased slightly. The results showed a promising new approach for the biological denitrification of the secondary effluent of municipal wastewater treatment plant under low carbon source.