earticle

영어

Pham Tuan Linh2 and Gi Youn Kim
This study was carried out on 4 batch reactors to determine the specific ammonium oxidizing rate (SAOR), specific nitrate forming rate (SNFR) and inhibitory degree of nitrifying activities with saline concentrations. Under salt free condition ammonia was consumed during the reaction period within 200 min. When the salt level increased to 10, 20 and 30 g NaClL-1 in reactor, ammonia depletion took 250, 300 and above 350 min, respectively. During concentration above 10 g NaClL-1, there was nitrite accumulation. Also, at 30 g NaClL-1 ammonia did not depleted and NO2 --N
accumulated until the final reaction. Nitrate formation rates decreased with increasing salt concentration. SAOR and SNFR showed a decreasing trend as salinity concentrations were increased. The SAOR was reduced from 0.2 to 0.08 mg NH4+-N g-1VSS day-1 as the salt concentration increased from 0 to 30 g NaCLL-1. Similarly, the SNFR decreased from 0.26 kg
NO3--N kg-1VSS day-1 at saline free to 0.1 kg NO3--N kg-1VSS day-1 at saline 30 g L-1. A severe inhibition of nitrifiers activity was observed at increased salt concentrations. The inhibition ratio of specific ammonium oxidation rates were 17, 47 and 60% on the reactor of 10, 20 and 30 g NaClL-1 added, respectively. The inhibition ratio of specific nitrate forming rates also were inhibited 30, 53 and 62% on the reactor of 10, 20 and 30 g NaClL-1 added, respectively. As the salinity concentrations increased from 0 to 30 mg NaClL-1, the average MLSS concentration increased from 1,245 to 1,735 mgL-1. The SS concentration of supernatant in reactor which settled about 30 minutes was not severely difference between concentration of salt free reactor and one of those high salt contained reactors.