| Abstract | U ovom radu istražen je učinak pH na parcijalnu nitrifikaciju. Provedeni su diskontinuirani pokusi nitrifikacije, pri pH vrijednostima: (i) pH = 8,0; (ii) pH = 7,2 - 7,4; (iii) pH = 7,5 i (iv) bez korekcije pH. Pokazano je da aktivni mulj provodi proces nitrifikacije uz prevođenje NH4-N u aerobnim uvjetima do NO2-N i NO3-N. Na temelju dobivenih rezultata istaknut je učinak pH na aktivnost nitritacije; pH ~ 7,0 (7,2 - 7,4) > nakupljanje NO2-N > pH = 8,0. Nadalje, nitrifikacija pri pH 8,0 pokazuje nakupljanje NO2-N koji čini oko 50 % oksidiranog NH4-N. Preostali dio čini NO3-N. Nitrifikacija pri pH 7,2 - 7,4 pokazuje nakupljanje i NO2-N i NO3-N, s tim da je oksidacija NH4-N u korist NO3-N od 50 - 70 %. Nitrifikacija bez korekcije pH vrijednosti, pri čemu je pH bila oko 8,0 pokazuje istu aktivnost kao i u procesu uz korekciju pH na 8,0. |
| Abstract (english) | This study examined the effect of pH on partial nitrification. Discontinuous experiments of nitrification, at a pH of: (i) pH = 8.0; (ii) pH = 7.2 – 7.4; (iii) pH = 7.5 and (iv) without pH correction. Our experiments showed that activated sludge performed process of nitrification with conversion of NH4-N to NO2-N and NO3-N under aerobic conditions. Based on the experimental results, the effect of pH on activity of nitritation is highlighted; pH ~ 7.0 (7.2 – 7.4) > accumulation NO2-N > pH = 8.0. Furthermore, nitrification showed accumulation of NO2-N which was cca 50 % of oxidised NH4-N at the pH value of 8.0. The remaining fraction was NO3-N. Nitrification at a pH of 7.2 - 7.4 showed accumulation of both, NO2-N and NO3-N, and the oxidation of NH4-N towards NO3-N which accounts for 50 - 70 % of reduction. Nitrification without pH corrections where the pH was around 8 shows the same activity as the process of nitrification with pH correction to 8.0. |
