Effect of sludge retention time on the biological performance of anaerobic membrane bioreactors treating corn-to-ethanol thin stillage with high lipid content.
The potential of anaerobic membrane bioreactors (AnMBRs) for the treatment of lipid rich corn-to-ethanol thin stillage was investigated at three different sludge retention times (SRT), i.e. 20, 30 and 50 days. The membrane assisted biomass retention in AnMBRs provided an excellent solution to sludge washout problems reported for the treatment of lipid rich wastewaters by granular sludge bed reactors. The AnMBRs achieved high COD removal efficiencies up to 99% and excellent effluent quality. Although higher organic loading rates (OLRs) up to 8.0 kg COD m(-3) d(-1) could be applied to the reactors operated at shorter SRTs, better biological degradation efficiencies, i.e. up to 83%, was achieved at increased SRTs. Severe long chain fatty acid (LCFA) inhibition was observed at 50 days SRT, possibly caused by the extensive dissolution of LCFA in the reactor broth, inhibiting the methanogenic biomass. Physicochemical mechanisms such as precipitation with divalent cations and adsorption on the sludge played an important role in the occurrence of LCFA removal, conversion, and inhibition.
Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Watermanagement, Sanitary Engineering Section, Stevinweg 1, 2628 CN Delft, The Netherlands; Istanbul Technical University, Faculty of Civil Engineering, Department of Environmental Engineering, Maslak, 34469 Istanbul, Turkey; Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands. Electronic address: derelir@itu.edu.tr.
Recep Kaan
RK
Dereli
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands.
Frank P
FP
van der Zee
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands.
Barry
B
Heffernan
Biothane Systems International, Tanthofdreef 21, 2600 GB Delft, The Netherlands; Veolia Environnement Recherche et Innovation, Chemin de la Digue, BP 76, 78603 Maisons-Laffitte Cedex, France.
Aurelie
A
Grelot
Delft University of Technology, Faculty of Civil Engineering and Geosciences, Department of Watermanagement, Sanitary Engineering Section, Stevinweg 1, 2628 CN Delft, The Netherlands.
Jules B
JB
van Lier
D000693:Anaerobiosis / Q000187:drug effects; D001673:Biodegradation, Environmental / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D002118:Calcium / Q000737:chemistry; D011232:Chemical Precipitation; D000431:Ethanol / Q000378:metabolism*; D005227:Fatty Acids / Q000494:pharmacology; D008274:Magnesium / Q000737:chemistry; D008567:Membranes, Artificial; D008697:Methane / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors; D062065:Wastewater / Q000737:chemistry; D003313:Zea mays / Q000187:drug effects / Q000378:metabolism*
D002118:Calcium; D000431:Ethanol; D005227:Fatty Acids; D008274:Magnesium; D008567:Membranes, Artificial; D008697:Methane; D010100:Oxygen; D012722:Sewage; D062065:Wastewater
Adsorption; Anaerobic membrane bioreactors; Calcium; Corn-to-ethanol thin stillage; Lipid; Long chain fatty acids; Magnesium; Methanogenic activity; Precipitation