In this study

the performance of a sequencing batch biofilm reactor (SBBR) for removal of nitrogen and phosphorus from swine wastewater was evaluated. The replacement rate of wastewater was set at 12.5% throughout the experiment. The anaerobic and aerobic times were 3 h and 7 h

respectively

and the dissolved oxygen concentration of the aerobic phase was about 3.95 mg·L

-1

. The SBBR process demonstrated good performance in treating swine wastewater. The percentage removal of total chemical oxygen demand (COD)

ammonia nitrogen (NH

4

+

-N)

total nitrogen (TN)

and total phosphorus (TP) was 98.2%

95.7%

95.6%

and 96.2% at effluent concentrations of COD 85.6mg·L

-1

NH

4

+

-N 35.22mg·L

-1

TN44.64 mg·L

-1

and TP 1.13mg·L

-1

respectively. Simultaneous nitrification and denitrification phenomenon was observed. Further improvement in removal efficiency of NH

4

+

-N and TN occurred at COD/TN ratio of 11:1

with effluent concentrations at NH

4

+

-N 18.5 mg·L

-1

and TN 34 mg·L

-1

while no such improvement in COD and TP removal was found. Microbial electron microscopy analysis showed that

the filler surfacewas coveredwith a thick biofilm

forming an anaerobic-aerobicmicroenvironment and facilitating the removal of nitrogen

phosphorus and organicmatters. A long-termexperiment (15 weeks) showed that stable removal efficiency for N and P could be achieved in the SBBR system.