Enhanced membrane filtration of wood hydrolysates for hemicelluloses recovery by pretreatment with polymeric adsorbents

•Ultrafiltration of lignin-containing wood hydrolysates is challenging.•Adsorption pretreatment with XAD-7 and XAD-16 enhances ultrafiltration capacity.•Ligneous compounds adsorbed on multiple layers on XAD-16.•Disadvantage of the pretreatment is hemicellulose losses. In this study adsorption of foulants from birch and pine/eucalyptus wood hydrolysates on two polymeric adsorbents was studied aiming to reduce the membrane fouling. The effect of the pretreatment of hydrolysate on polyethersulphone membrane performance was studied in dead-end filtration experiments. Adsorption pretreatment improved significantly filtration capacity and decreased membrane fouling. Especially high-molecular weight lignin was efficiently removed. A multistep adsorption pretreatment was found to reduce the amount of adsorbent required. While large adsorbent amount was shown to increase flux in filtration, it was found also to cause significant hemicellulose losses.