| Abstract | U ovom radu istražena je denitrifikacija sintetske otpadne vode s visokom koncentracijom nitrata 250±5 mg NO₃-N/L pri omjerima C/N 1, 2 i 3 uz natrijev acetat kao izvor ugljika. Omjeri C/N 1 i 2 nisu bili dovoljni za potpunu denitrifikaciju, pri čemu je postignuto 26,2 % i 78,7 % smanjenje koncentracije NO3-N. Također, pri omjerima C/N 1 i 2, nakon utroška acetata, s unutarstaničnim rezervama je postignuta sveukupno 40,9 % i 91,2 % redukcija nitrata. Pri omjeru C/N 3 ostvareno je 99,2 % smanjenje koncentracije nitrata. Ostvarene brzine denitrifikacije su iznosile 33 mg NO₃-N/Lh, 32,7 mg NO₃-N/Lh i 33,6 mg NO₃-N/Lh pri omjerima C/N 1, 2 i 3, a pri omjerima C/N 1 i 2 brzine denitrifikacije s unutstastaničnim zalihama su iznosle 6,7 mg NO₃-N/Lh i 20,7 mg NO₃-N/Lh. Nitrit, iako se nakupljao pri sva tri omjera, nije se pokazao kao limitirajući faktor jer su mikroorganizmi aktivnog mulja bili aklimatizirani na visoke koncentracije nitrita. |
| Abstract (english) | In this paper the denitrification of synthetic wastewater with high nitrate concentration of 250±5 mg NO₃-N/L at C/N ratios of 1, 2 and 3 with sodium acetate as a carbon source was investigated. C/N ratios 1 and 2 were not sufficient for complete denitrification, whereby 26.2 % and 78.7 % reduction in NO₃-N concentration was achieved. Also, at C/N ratios 1 and 2, after acetate consumption, a total of 40.9 % and 91.2 % nitrate reduction was achieved with intracellular reserves. At the C/N ratio of 3, a 99.2 % reduction in nitrate concentration was achieved. The achieved denitrification rates were 33 mg NO₃-N/Lh, 32.7 mg NO₃-N/Lh and 33.6 mg NO₃-N/Lh at C/N ratios 1, 2 and 3, and at C/N ratios 1 and 2 denitrification rates with intracellular reserves were 6.7 mg NO₃-N/Lh and 20.7 mg NO₃-N/Lh. Although nitrite accumulated at all three ratios, it did not prove to be a limiting factor because the microorganisms in the activated sludge were acclimatized to high concentrations of nitrite. |
