Biological nitrogen removal using bio-sorbed internal organic carbon from piggery wastewater in a post-denitrification MLE process.
Nitrogen removal from a piggery wastewater was investigated in a post-denitrification modified Lüdzack Ettinger (PDMLE) process. Overall hydraulic retention time (HRT) of the PDMLE, consisting of contact/separator (C/S), nitrification, denitrification and re-aerobic bioreactor was 10 days. 60% of the influent SCOD was separated in the C/S by contacting the return sludge with the synthetic wastewater, however, only 10% of the influent SCOD was separated from the piggery wastewater. Biosorption capacities of the synthetic wastewater and piggery wastewater were 800 and 150 mg/g-MLSS, respectively. In spite of the high organic and nitrogen load, nitrification efficiency was above 95%, and nitrification rate was about 180 mg-NH4+-N/L x day. The removed delta COD/delta nitrate ratios in the denitrification tank were 4.0 and 11.5 g-SCOD/g-nitrate, while denitrification rates were 8.4 and 2.6 mg-nitrate/day for synthetic and piggery wastewater, respectively. In the proposed PDMLE process, both bio-sorbed and bypassed organic matter could be successfully used for nitrate reduction as carbon sources and the final TN removal efficiency was as high as 95%.
Park
S M
SM
Department of Environmental Engineering, Chungbuk National University, San 48 Kaeshindong Cheongju, Korea 361-763. psm37@hanmail.net
Jun
H B
HB
Chung
Y J
YJ
Lee
S H
SH
D000327:Adsorption; D000818:Animals; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry; D008372:Manure; D008962:Models, Theoretical; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism*; D013552:Swine; D014865:Waste Disposal, Fluid / Q000379:methods*; D014872:Water Movements; D014873:Water Pollutants / Q000302:isolation & purification* / Q000378:metabolism*
D008372:Manure; D014873:Water Pollutants; D002244:Carbon; D009584:Nitrogen