| 摘要 |
PURPOSE:To oxidize and convert NH4<+> efficiently into nitrous acid in the former stage of denitrification treatment, by suspending ammonia-oxidizing bacteria in an aqueous solution of sodium alginate, adding the resultant suspension to a solution of CaCl2, and using the resultant particulate gels entrapping immobilized bacterial cells in calcium alginate. CONSTITUTION:Ammonia-oxiding bacteria, e.g. Nitrosomonas europaea ATCC19718, are cultivated in a culture medium for the ammonia-oxidizing bacteria, and concentrated in a centifuge, etc. to give bacterial cells, which are then suspended in an aqueous solution of sodium alginate. The resultant suspension is then dropped to a solution of calcium chloride to afford particulate gels entrapping the immobilized bacterial cells in calcium alginate. The resultant particulate gels are then used to oxidize ammonia into nitrous acid within 20-25 deg.C range at an almost weak alkaline pH value. Thus, the denitrification treatment of the ammonium ions is carried out in the former stage. |
