| Abstract | U ovom radu istražen je učinak raspoloživog biorazgradivog organskog opterećenja (KPK) na uklanjanje nutrijenata, dušika i fosfata. Pokusi su provedeni pri aerobnim uvjetima, uz početnu koncentraciju 10,7–18,2 mg PO43--P L-1 i 48±1,3 mg NH4+-N L-1 i pri omjeru C/N 1, 3, 4, 5, 6 i 7. Kao izvor ugljika korišten je natrijev acetat. Rezultati pokazuju da aktivni mulj ima aktivnost za istovremeno uklanjanje N i fosfata. S povećanjem omjera C/N proporcionalno je veće uklanjanje N, koje pri C/N 1, 3, 4, 5, 6 i 7 iznosi 14,3%, 33,3%, 41,9%, 35,4%, 77,6% i 89,7%. Povećanjem omjera C/N povećava se uklanjanje ukupnog dušika, i pri C/N 1 iznosi 14,3%, a pri C/N 7 iznosi 89,7%. Najveće uklanjanje fosfata od 60,7% je postignuto pri omjeru C/N 4. Profili pH i otopljenog kisika neizravni su pokazatelji mikrobnih reakcija tijekom uklanjanja N i P. |
| Abstract (english) | The effect of organic load (biodegradable COD) on biological nutrient removal (nitrogen and phosphate) was investigated. The experiments were conducted at aerobic conditions, at an initial concentration of 10.7–18.2 mg PO43--P L-1 and 48±1.3 mg NH4+-N L-1 at a C/N ratio of 1, 3, 4, 5, 6 and 7. Sodium acetate was used as a carbon source. The results show that activated sludge has the ability to simultaneously remove nitrogen and phosphate. By increasing the C/N ratio, nitrogen removal increased as well. The nitrogen removal at C/N 1, 3, 4, 5, 6 and 7 was 14.3%, 33.3%, 41.9%, 35.4%, 77.6% i 89.7%. Also, an increased C/N ratio resulted in an increased total nitrogen removal, and at a C/N 1 and C/N 7, the total nitrogen removal was 14.3% and 89.7%, respectively. The biggest phosphate removal of 60.7 % was achieved at C/N 4. DO and pH profiles are indirect indicators of microbial reactions during N and P removal. |
