Performance of mesoporous adsorbent resin and powdered activated carbon in mitigating ultrafiltration membrane fouling caused by algal extracellular organic matter Original Research Article

This paper focused on the control of ultrafiltration (UF) membrane fouling caused by extracellular organic matter (EOM) extracted from Microcystis aeruginosa through pretreatment with mesoporous adsorbent resin (MAR) and powdered activated carbon (PAC). The influence of MAR and PAC pretreatments on characteristics of EOM was investigated using molecular weight (MW) fractionation, DAX-8/XAD-4 resin fractionation and fluorescence excitation-emission matrix (EEM) spectroscopy. The results suggested that MAR mainly removed high-MW (> 100 kDa) fraction of EOM, while PAC primarily adsorbed low-MW (< 1 kDa) fraction. Both MAR and PAC adsorption removed more hydrophobic fraction than hydrophilic fraction. UF experiments were carried out to evaluate the efficacies of MAR and PAC pretreatments in EOM fouling control. MAR pretreatment significantly reduced the reversible fouling due to the efficient removal of high-MW fraction and the consequent reduction of cake formation; whereas PAC exhibited little ability in alleviating the reversible fouling. Nevertheless, the irreversible fouling, which accounted for a small part of the total fouling, was mitigated by both MAR and PAC pretreatments because they both reduced irreversible adhesion caused by hydrophobic EOM. Overall, with respect to EOM fouling control, MAR was much more efficient than PAC.