Effect of coal gangue-fly ash ceramic (CFC) media on municipal wastewater treatment in a pre-denitrification biological aerated filter

Coal gangue-flyash ceramic (CFC) is a novel media, which is made up of flyash, coal gangue powder and some kinds of additive. In this study, CFC was used as filter medium for a pre-denitrification biological aerated filter (BAF) to treat municipal wastewater. The performances of the two pilot-scale pre-denitrification BAF systems were monitored for 3 months to compare the effect of CFC media with expanded clay media as BAF medium. In terms of started-up speed, the efficiency of the system with expanded clay media was slightly faster than that with CFC media. In terms of removing chemical oxygen demand (COD), ammonia (NH(4)(+)-N) and total nitrogen (TN), the efficiency of the system with CFC media almost could rival with expanded clay media. The average COD, NH(4)(+)-N and TN concentrations in the effluent were average 47.0 mg/L, 4.0 mg/L and 14.8 mg/L when HRT was 4 h, which were all up to the National Discharge Standard of Level 1-A (GB 18918-2002) in China. So it is feasible for CFC media to be applied as the media of BAF.