Effect of sludge retention time on the biological performance of anaerobic membrane bioreactors treating corn-to-ethanol thin stillage with high lipid content

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• 作者：Recep Kaan Dereli ; Frank P. van der Zee ; Barry Heffernan ; Aurelie Grelot ; Jules B. van Lier
• 关键词：Adsorption ; Anaerobic membrane bioreactors ; Calcium ; Corn-to-ethanol thin stillage ; Lipid ; Long chain fatty acids ; Magnesium ; Methanogenic activity ; Precipitation
• 刊名：Water Research
• 出版年：1 February, 2014
• 年：2014
• 卷：49
• 期：Complete
• 页码：453-464
• 全文大小：1239 K

文摘

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聽kg COD聽m^鈭?聽d^鈭? 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.