Simultaneous removal of organic matter and nitrogen from milking parlor wastewater by a magnetic activated sludge (MAS) process.
The magnetic activated sludge (MAS) process is a modification of the conventional activated sludge process to improve the solid-liquid separation characteristics. It was developed to reduce the production of excess sludge and the time required for the conventional activated sludge process. In this study, actual milking parlor wastewater was treated with a MAS process and no sludge was removed. The effectiveness of continuous aeration and intermittent aeration in removing organic matter and nitrogen were compared. Both processes were highly efficient at removing chemical oxygen demand (COD) (averaged 91% removal) and ammonium nitrogen (NH(4)-N) (averaged 99% removal). In marked contrast to the continuous aeration process, the 30-min aeration/90-min non-aeration cycle of the intermittent aeration process rapidly reduced the nitrate nitrogen (NO(3)-N) concentration to near-zero. This result indicates that NO(3)-N was almost completely denitrified via nitrite nitrogen (NO(2)-N) to nitrogen gas. Removal of organic material and nitrogen can be considered to have occurred simultaneously in the single tank of the MAS process.
Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro 080-8555, Japan.
Chun
C
Ying
Kazutaka
K
Umetsu
Ikko
I
Ihara
Yasuzo
Y
Sakai
Takaki
T
Yamashiro
D000818:Animals; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D003612:Dairying; D008280:Magnetics / Q000379:methods*; D008892:Milk; D009566:Nitrates / Q000302:isolation & purification; D009584:Nitrogen / Q000302:isolation & purification*; D009930:Organic Chemicals / Q000302:isolation & purification*; D010100:Oxygen / Q000302:isolation & purification; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors; D014835:Volatilization; D014865:Waste Disposal, Fluid / Q000379:methods*
D009566:Nitrates; D009930:Organic Chemicals; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009584:Nitrogen; D010100:Oxygen