Keywords: moving-bed biofilm reactors, oxygen uptake rate, nitrification, denitrification, municipal wastewater, wastewater treatment, bioactivity, activated sludge, ammonium oxidation, COD removal, chemical oxygen demand
Characteristics of municipal wastewater treatment by moving-bed biofilm reactor
In this paper, the bio-activity of activated sludge was investigated using Oxygen Uptake Rate (OUR) as an indicator. The activity of ammonium oxidation and COD removal of both attached- and suspended-growth sludge was determined under different temperature and organic loading rates. The experimental results indicated that at 5°C, the nitrification activity was about 60% of that at 18°C. The nitrification activity of attached sludge was 20-30% lower in comparison with suspended sludge. The denitrification rate of sludge in zones I and II was 0.44 mg NO3−/g MLSS•h and 0.63 mg NO3−/g MLSS•h, respectively, which revealed that the denitrification activity of sludge-II was higher compared with sludge-I, the results also indicated that the accumulation of nitrite was very low.