Evaluation of various pretreatment methods to manage fouling in ultrafiltration of wood hydrolysates

The hydrophobic PSu membrane was fouled more in the experiments than the hydrophilic RC membrane. In tests with the PSu membrane, the most significant improvement in filterability was achieved when pulsed corona discharge (PCD) treatment, an oxidation method, was used as pretreatment. The PCD treatment, which was tested only for the PSu membrane, increased the flux over sixfold compared to filtration of untreated spruce hydrolysate. Other pretreatment methods, such as activated carbon adsorption and pH adjustment, which were tested with both membranes, also had positive effects on the filtration capacity. The results of this study indicate that pretreatment processes have to be tailored separately for different hydrolysates due to their different characteristics.