4 research outputs found
Performance of Moving Bed Biofilm Reactors for Biological Nitrogen Compounds Removal from Wastewater by Partia; Nitrification-Dentrifiction Process
In this research, the continuously operated laboratory scale Kaldnes
(k1) moving bed biofilm reactors (MBBRs) under partial
nitrification-denitrification process were used for treatment of
synthetic wastewater containing ammonium and glucose. The Anoxic and
Aerobic reactors were filled to 40 and 50 %( v/v) to attach and retain
biomass with k1 biofilm carriers, respectively. The favorite internal
recycle ratio and hydraulic residence time (HRT) to eliminate nitrogen
compounds were 300% of inflow rate and 20 hours, respectively. Optimal
dissolved oxygen (DO) was 1-1.5 mg/L in the aerobic reactor. No sludge
was returned into the system and only an internal recycling was
performed from aerobic to anoxic reactor. The results showed that the
maximum and average specific nitrification rate (SNR) in the aerobic
reactor were 49.4 and 16.6 g NOx-N/KgVSS.day, respectively and the
maximum and average specific denitrification rate (SDNR) as 156.8 and
40.1gNOx-N/KgVSS.day in the anoxic reactor, respectively. The results
also showed that it is possible to reach a stable partial nitrification
with high ratio of NO2-N/NOx-N (80% to 85%) during high load ammonium
and low DO concentration (>1.5 mg/L) in the aerobic reactor. During
optimum conditions, the average removal efficiency of total nitrogen
(TN), ammonia and soluble organic carbon (SCOD) occurred as 98.23%,
99.75% and 99.4%, respectively. This study showed that the partial
nitrification/denitrification process in the moving bed biofilm
reactors system has an acceptable performance for treatment of
wastewater with high load of organic carbon and organic nitrogen
compounds