Nitrification and denitrification in the wastewater treatment process : master's thesis

Osnovni cilj diplomskog rada je istraživanje bioloških metoda pročišćavanja otpadnih voda, nastalih prilikom prodora oborinskih voda ili tijekom procesa biorazgradnje otpada sa odlagališta Jakuševac. U svrhu ispitivanja kakvoće otpadnih voda, provedene su analize i mjerenja nekoliko ključnih parametara: biološka potrošnja kisika (BPK), kemijska potrošnja kisika (KPK), masene koncentracije nitrata, nitrita i amonijevog kationa te pH vrijednost otpadnih voda. Poseban naglasak dan je na procese nitrifikacije i denitrifikacije, odnosno proučavanje utjecaja koncentracije aktivnog mulja na brzinu nitrifikacije te određivanje optimalnog volumena etanola koji je potreban za potpunu denitrifikaciju. Zaključuje se da je smanjenjem količine aktivnog mulja, smanjena i brzina nitrifikacije, a porastom temperature, povećava se i brzina denitrifikacije. Proces denitrifikacije postiže potpuno uklanjanje nitrata i nitrita iz sustava uz upotrebu dodatka suviška etanola, što rezultira koncentracijama nitrata i nitrita koje su u skladu sa zakonskom regulativom.The main objective of this graduate thesis is to investigate biological methods for purifying wastewater generated during the infiltration of rainwater or the waste biodegradation process at the Jakuševac landfill. In order to assess the quality of wastewater, analyses and measurements of several key parameters were conducted: biological oxygen demand (BOD), chemical oxygen demand (COD), mass concentrations of nitrates, nitrites, and ammonium ions, as well as the pH value of the wastewater. Special emphasis was placed on the processes of nitrification and denitrification, including studying the influence of activated sludge concentration on nitrification rate and determining the optimal volume of ethanol required for complete denitrification. It is concluded that reducing the amount of activated sludge reduces the nitrification rate, while increasing temperature also increases the denitrification rate. The denitrification process achieves the complete removal of nitrates and nitrites from the system with the addition of an excess of ethanol, resulting in nitrate and nitrite concentrations that comply with legal regulations