Performance of CANON process in a sequencing batch biofilm reactor and influence of temperarure.

Characteristics of CANON process in a laboratory-scale sequencing batch biofilm reactor were studied and effects of temperature on nitrogen removal performance were also examined.The total nitrogen removal rate of 88.3% and the total nitrogen removal load of 0.52kg N/(m3.d) of the reactor were achieved,which could prove that CANON process really occurred and prevailed in sequencing batch biofilm reactor.During a batch operation period,changes of nitrite concentration in the reactor could be separated into three phases:up phase,stationary phase and down phase.Although the break-point of DO curve appeared earlier than that of pH curve during a reaction period,both of the two break-points could indicate the termination of CANON reaction.When the liquor temperature was 26～35℃,the reactor showed excellent nitritation performance and most of total nitrogen was disappeared.When the liquor temperature was below 20 ℃,anaerobic ammonium oxidation reaction was inhibited seriously and resulted in a large amount of nitrite accumulation in the reactor.And nitritation reaction was inhibited seriously when the liquor temperature was below 15℃.The optimum temperature for anaerobic ammonium oxidation bacteria growth was about 30℃.