Coupled anaerobic-aerobic treatment of whey wastewater in a sequencing batch reactor: proof of concept.
A proof of concept was performed in order to verify if the coupling of anaerobic and aerobic conditions inside the same digester could efficiently treat a reconstituted whey wastewater at 21 degrees C. The sequencing batch reactor (SBR) cycles combined initial anaerobic phase and final aerobic phase with reduced aeration. A series of 24 h cycles in 0.5 L digesters, with four different levels of oxygenation (none, 54, 108 and 182 mgO2 per gram of chemical oxygen demand (COD)), showed residual soluble chemical oxygen demand (sCOD) of 683 +/- 46, 720 +/- 33, 581 +/- 45, 1239 +/- 15 mg L(-1), respectively. Acetate and hydrogen specific activities were maintained for the anaerobic digester, but decreased by 10-25% for the acetate and by 20-50% for the hydrogen, in the coupled digesters. The experiment was repeated using 48 h cycles with limited aeration during 6 or 16 hours at 54 and 108 mgO2gCODinitial(-1), displaying residual sCOD of 177 +/- 43, 137 +/- 38, 104 +/- 22 and 112 +/- 9 mgL(-1) for the anaerobic and the coupled digesters, respectively. The coupled digesters recovered after a pH shock with residual sCOD as low as 132 mg L(-1) compared to 636 mg L(-1) for the anaerobic digester. With regard to the obtained results, the feasibility of the anaerobic-aerobic coupling in SBR digesters for the treatment of whey wastewater was demonstrated.
Frigon
J C
JC
Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount, Montreal H4P 2R2, Canada. jean-claude.frigon@cnrc-nrc.gc.ca
Bruneau
T
T
Moletta
R
R
Guiot
S R
SR
D000085:Acetates / Q000032:analysis; D001420:Bacteria, Aerobic / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors; D002849:Chromatography, Gas; D006859:Hydrogen / Q000032:analysis; D008894:Milk Proteins / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010865:Pilot Projects; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis; D000067816:Whey Proteins
D000085:Acetates; D008894:Milk Proteins; D014874:Water Pollutants, Chemical; D000067816:Whey Proteins; D006859:Hydrogen; D010100:Oxygen