Start-up of anaerobic ammonium oxidation process in anaerobic sequencing batch reactor

The cultivation of anaerobic ammonium oxidation sludge was studied with the anaerobic sequencing batch reactor seeded with aerobic nitrified sludge.Under the condition that the influent pH value ranged 7.2-7.8 and the temperature was 30 ± 1 ℃,the ANAMMOX sludge was successfully cultivated after 142 d.During the operation time,the sludge quantity(counted by VSS) in reactor increased from 9.90 g/L to 18.99 g/L,when the hydraulic retention time was 1.20 d and the volume loading of total nitrogen was 0.431 8 kg/(m3·d),the highest removal rate of total nitrogen,ammonia nitrogen,nitrite-nitrogen reached 93.3%,93.9% and 99.8% respectively,while,the average rate were 80.5%,81.2% and 85.7% respectively.The ratio of ammonia nitrogen and nitrite-nitrogen removal was 1 ∶ 1.387 ± 0.024.The results of the optimized experiment of the said process show that:the ANAMMOX reactor can reach a high performance with pH value ranged 7.2-7.8 at 35 ℃;and the modest intensity of denitrification was in favor of the improvement of the denitrification performance of the ANAMMOX reactor.