The inhibition phenomenon of denitrification process of later period leachate and its elimination

The lack of carbon sources for denitrification of later period leachate with high ammonia nitrogen concentration and low C/N could create the nitrous acid A/O denitrification system with concentration higher than 200mgN/L, while this accumulation inhibited obviously the ammonia and nitrous acid oxidation processes. The anaerobic treatment in A2/O technological process provided readable biodegradable organic carbon source for the follow-up denitrification through hydrolysis acidification action of the refractory organics and eliminated the nitrite accumulation and its inhibition on nitrification process. The anaerobic treatment could enhanced the velocities of ammonia oxidation and denitrification, about 1 and 1.3 multiples, reaching 0.123mgN/(mgMLSSd) and 0.0675mgN/(mgMLSSd), respectively. The TN removal rate increased from 8% to 15%. The ammonia nitrogen with concentration high up to 1000mg/L might be oxidated to be safe nitrate rather basically, under the influent water load of 0.138mgN/(mgMLSSd).