Microbial Immobilization Technology And Its Applications In The Biological Nitrogen Removal

The paper researches a way to enrich ammonia oxidizing bacteria by controlling influent HCO₃^-/NH₄⁺-N under the condition of intermittent aeration. When influent HCO₃^-/NH₄⁺-N is between 6.31～7.57, effluent accumulation of nitrit is above 96.1%. Furthermore, the experiment invents a method to make technology of immobilized cell more economical. Carrier contains 5.5%PVA,0.45%CA,0.5%SiO₂,then dropping it to the mixture of saturated boracic acid and 0.6% aluminium sulfate. After 24h,Bring it into oven for 3.5h under 30℃. By this way, the cost will be saved 31.63%, and the recovery of activity is above 78%. Finally, experiment finds that when the temperature is between 28℃～29℃, and DO is about 5.6mg/L,and pH is between 7.6～8.4, the stimulant wastewater has the best treating effect. Nitrification rate achieves 26.6mg/(L·h) and accumulation of nitrit is about 97.8%. at the same condition, when Industrial Effluent from Synthetic Ammonia Plant is treated, nitrification rate achieves 22.6mg/(L·h) and accumulation of nitrit is about 79.6%.