Scholarly Articles
유입흐름 변경 및 전응집 기반 이단응집 제어적용 MBR을 통한 총인처리 개선 연구
Journals
상하수도학회
Author
차재환,신경숙,박승국,신정훈,김병군
Publication Date
20170224
A membrane bioreactor by sequentially alternating the inflow and by applying a two-stage coagulation control based
on pre-coagulation was evaluated in terms of phosphorus removal efficiency and cost-savings. The MBR consisted of
two identical alternative reaction tanks, followed by aerobic, anoxic and membrane tanks, where the wastewater and
the internal return sludge alternatively flowed into each alternative reaction tank at every 2 hours. In the batch-operated
alternative reaction tank, the initial concentration of nitrate rapidly decreased from 2.3 to 0.4 mg/L for only 20 minutes
after stopping the inflow, followed by substantial release of phosphorus up to 4 mg/L under anaerobic condition. Jar
test showed that the minimum alum doses to reduce the initial PO4-P below 0.2 mg/L were 2 and 9 mol-Al/mol-P
in the wastewater and the activated sludge from the membrane tank, respectively. It implies that a pre-coagulation
in influent is more cost-efficient for phosphorus removal than the coagulation in the bioreactor. On the result of NUR
test, there were little difference in terms of denitrification rate and contents of readily biodegradable COD between
raw wastewater and pre-coagulated wastewater. When adding alum into the aerobic tank, alum doses above 26 mg/L
as Al2O3 caused inhibitory effects on ammonia oxidation. Using the two-stage coagulation control based on pre-coagulation,
the P concentration in the MBR effluent was kept below 0.2 mg/L with the alum of 2.7 mg/L as Al2O3, which was
much lower than 5.1∼7.4 mg/L as Al2O3 required for typical wastewater treatment plants. During the long-term operation
of MBR, there was no change of the TMP increase rate before and after alum addition.
on pre-coagulation was evaluated in terms of phosphorus removal efficiency and cost-savings. The MBR consisted of
two identical alternative reaction tanks, followed by aerobic, anoxic and membrane tanks, where the wastewater and
the internal return sludge alternatively flowed into each alternative reaction tank at every 2 hours. In the batch-operated
alternative reaction tank, the initial concentration of nitrate rapidly decreased from 2.3 to 0.4 mg/L for only 20 minutes
after stopping the inflow, followed by substantial release of phosphorus up to 4 mg/L under anaerobic condition. Jar
test showed that the minimum alum doses to reduce the initial PO4-P below 0.2 mg/L were 2 and 9 mol-Al/mol-P
in the wastewater and the activated sludge from the membrane tank, respectively. It implies that a pre-coagulation
in influent is more cost-efficient for phosphorus removal than the coagulation in the bioreactor. On the result of NUR
test, there were little difference in terms of denitrification rate and contents of readily biodegradable COD between
raw wastewater and pre-coagulated wastewater. When adding alum into the aerobic tank, alum doses above 26 mg/L
as Al2O3 caused inhibitory effects on ammonia oxidation. Using the two-stage coagulation control based on pre-coagulation,
the P concentration in the MBR effluent was kept below 0.2 mg/L with the alum of 2.7 mg/L as Al2O3, which was
much lower than 5.1∼7.4 mg/L as Al2O3 required for typical wastewater treatment plants. During the long-term operation
of MBR, there was no change of the TMP increase rate before and after alum addition.