Metagenomics reveals a full-scale modified integrated fixed-film activated sludge process: Enhanced nitrogen removal and reduced sludge production

This study provides a side-by-side comparative investigation between the full-scale conventional activated sludge (CAS) and the high-concentration powder carrier bio-fluidized bed (HPB) processes. The results showed that the HPB total nitrogen removal efficiency increased by 10.86 % more than CAS. The anammox pathway increased by 6.92 %, while the simultaneous nitrification-denitrification pathway increased by 4.27 %. Also, the effluent's total nitrogen of the HPB process was stabilized below 10 mg/L, which can withstand the impact of industrial wastewater bet -ter. More energy and substance (protein) were consumed to attach to the carriers and resist external selective pressure to produce extracellular polymeric substance rather than sludge production in the HPB process. For a 10,000 m(3)/d HPB wastewater treatment plant, lowering the total nitrogen and sludge production saved $110,369.64 in annual operating costs.

Automated summary

This study compares the performance of the full-scale conventional activated sludge (CAS) and the high-concentration powder carrier bio-fluidized bed (HPB) processes. The results show that the HPB process has a higher total nitrogen removal efficiency and can stabilize the effluent's total nitrogen below 10 mg/L, while reducing sludge production.