This study was conducted to develop a new RBC process available for the effective removal of organic matters and nitrogen in sewage. The RBC process for the oxidation organic compounds and nitrification was designed to occur at the 1st-stage and next-stage RBC respectively. Then nitrified water was recycled to the denitrifying RBC located at the lower part of the 1st-stage RBC. Some results were summarized as follows. 1. The loading limitation was represented as $60g{\cdot}COD/gm^2/day$ in experiment of simultaneous removal of organic matter and nitrogen. The maxmum COD % removal was 85% at the load $35g{\cdot}COD/m^2/day$. 2. The $NO_3-N$ % removal was approximately 80% at the load $60g{\cdot}COD/m^2/day$ and the maximum $NO_3-N$ remaval rate was $3.9g{\cdot}COD/m^2/day$ and the overall C/N ratio of 11.0 as required to achive 80% of $NO_3-N$% removal. 3.$NO_3-N$ removal rate was rapidly decreased above the load $7g{\cdot}NH_4{^+}-N/m^2/day$ and the maximum $NO_3-N$ removal rate was $3.7g{\cdot}NO_3-N/m^2/day$. 4. Irrespective of the recycle ratio, the COD % removal at the system of 2-stage RBC unit was nearly constant as 89% while the maximum one in the 1st-stage unit was 77% in the case of 50% recycle. 5. The maximum COD % removal in the 3-stage RBC system was 93% while 1st-stage one being 80%, under the $NH_4{^+}-N$ load of $7.4g/m^2{\cdot}d$. Also maximum percentage of nitrification and denitrification was 69% and 41% respectively, under the same $NH_4{^+}-N$ load.

Eight Korean native black goats were used, of blood was collected from the Jugular vein into heparinized tubes a week interval. The heparinized blood was centrifuged for separation to blood plasma and corpuscles. The hematocrit, per centage of blood that is red blood cells, was reschuffuled of 10 %, 20 %, 30 %, 40 % and 50 % using blood plasma, 0.9 % NaCl solution and 5.4 % dextrose solution. The sedimentation rates of red blood cell obtained at and are summarized as follows. 1) The sedimentation rates of red blood cell were more increased by lower PCV%, i.e. there was a reverse relationship between the sedimentation rates and PCV% at any condition of these experiments. 2) The RBC were sedimented the most quickly in the NaCl solution and slower in the plasma compare with the dextrose solution at the same PCV%. 3) There was no temperature effect on the sedimentation rates between the two groups of and (at PCV 20% and 10%), even though the temperature difference is .

This study was conducted to investigate anoxic-RBC (rotating biological contactor) and its application in advanced municipal wastewater treatment process to remove biologically organics and ammonia nitrogen. Effluent COD and nitrogen concentration increased as the increase of volumetric loading rate. But, the concentration changes of NO2--N and NO3--N were little, as compared to COD and NH4+-N. When the volumetric loading rate increased, COD removal efficiency and nitrification appeared very high as 96.7～98.8% and 92.5～98.8%, respectively. However, denitrification rate decreased to 76.2～88.0%. These results showed that the change of volumetric loading rate affected to the denitrification rate more than COD removal efficiency or nitrification rate. The surface loading rates applied to RBC were 0.13～6.01g COD/㎡-day and 0.312～1.677g NH4+-N/㎡-day and they were increased as the increase of volumetric loading rate. However, the nitrification rate showed higher than 90%. The thickness of the biofilm in RBC was 0.130～0.141㎜ and the density of biofilm was 79.62～83.78㎎/㎤. They were increased as surface loading rate increased. From batch kinetic tests, the kmaxH and kmaxN were obtained as 1.586 g C/g VSS-day, and 0.276 g N/g VSS-day, respectively. Kinetic constants of denitrifer in anoxic reactor, Y, ke, Ks, and k were 0.678 ㎎ VSS/㎎ N, 0.0032 day-1, 29.0 ㎎ N/ℓ, and 0.108 day-1, respectively. P and Ks values of nitrification and organics removal in RBC were 0.556 g N/㎡-day and 18.71 g COD/㎡-day, respectively.

This research was performed to investigate the dynamics of microbial community by RBC (Rotating Biological Contactor) using Rhodococcus sp. EL-GT and activated sludge. Cell counts revealed by DAPI were compared with culturable bacterial counts from nutrient agar. Colony counts on nutrient agar gave values 20∼25% and 1∼15% of cell counts (DAPI). The cell counts for the dynamics of bacterial community were determined by combination of in situ hybridization with fluorescently-labelled oligonucleotide probes and epifluorescence microscopy. Around 90∼80% of total cells visualized by DAPI were also detected by the bacteria probe EUB 338. For both reactors proteobacteria belonging to the gamma subclass were dominant in the first stage (1 and 2 stage) and proteobacteria belonging to the gamma subclass were dominant in the last stage (3 and 4 stage).