Study On Immobilization Technology And The Application To Biodenitrification

Immobilized bioaugmentation technology and its application to the biodenitrification were mainly studied in this paper. Nitrifying bacteria and denitrifying bacteria were enriched and cultivated respectively. The results showed that the nitrifying bacteria cultivated by the simulated domestic wastewater increased at a great rate and had a good granularity, and was fit for the treatment of relative low-concentration ammoniac wastewater such as domestic wastewater.Some immobilized means were compared and the conclusion was as follows: the immobilized nitrifying bacteria, used with polyvinyl alcohol as entrapment agent mixed with sodium alginate, had great mechanical strength and aeration endurance. The immobilized denitrifying bacteria, used with sodium alginate as entrapment agent mixed with powdered activated carbon, was made simply and easily, and the relative efficiency was the highest.Immobilized nitrifying bacteria and denitrifying bacteria respectively, the results showed that the total inorganic nitrogen (TIN) removal rate by immobilized nitrifying bacteria was higher than free cells, and it could be improved with added organic carbon.Simultaneous nitrification and denitrification (SND) by coimmobilized nitrifying bacteria and denitrifying bacteria was also researched. The optimum aerating time, COD, pH and air volumetric flow rate was about 4h, 500mg/L-1000mg/L, 8.0*8.5 and 24L/h-42L/h respectively. On this condition, the denitrification velocity was high and the single-stage biodenitrification process could be carried out efficiently.