| Abstract | U ovom radu provedena su istraživanja nitritacije u diskontinuiranim pokusima. Istražena je aktivnost nitrificirajućih vrsta u aktivnom mulju za oksidaciju NH4-N do NO2-N, početnih vrijednosti 29,15±1,45 mg NH4-N/L, 25,9±16,1 mg NO3-N/L i 8,85±5,6 mg NO2-N/L. Ovim pokusima je pokazano da aktivni mulj provodi proces parcijalne nitrifikacije (nitritacije) pri koncentraciji otopljenog kisika < 1 mg/L i da je pri odabranim procesnim uvjetima: otopljeni kisik < 1 mg/L, temperatura 22,1±1,9 °C i pH = 8 aktivni mulj potpuno oksidirao NH4-N. Pri istraživanim početnim koncentracijama NH4-N, NO3-N i NO2-N, te izračunat omjer NO3-N/NO2-N 2,85±0,15 i odabrane procesne uvjete, parcijalna nitrifikacija se zbivala uz nakupljanje NO2-N od 38,3 - 75,4 % i NO3-N od 15,3 - 59,2 %. |
| Abstract (english) | In this study nitritation in discontinuous experiments was examined. The activity of nitrifying species in activated sludge for oxidation of NH4-N to NO2-N, with initial concentration of 29.15±1.45 mg NH4-N/L, 25.9±16.1 mg NO3-N/L and 8.85±5.6 mg NO2-N/L was investigated. In these experiments, the process of partial nitrification (nitritation) was achieved by activated sludge under dissolved oxygen concentration < 1 mg/L and under selected process parameters: dissolved oxygen concentration < 1 mg/L, temperature 22.1±1.9 °C and pH = 8, the complete NH4-N oxidation by activated sludge was obtained. Under investigated initial concentrations of NH4-N, NO3-N and NO2-N, and calculated NO3-N/NO2-N ratio of 2.85±0.15 and selected process conditions, the partial nitrification was performed with accumulation of NO2-N in range of 38.3 - 75.4% and NO3-N in range of 15.3 - 59.2 %. |
