Understanding membrane fouling control mechanisms of EOM by combined PACl/PMS using XDLVO-based interaction energy analysis

Understanding membrane fouling mechanisms, particularly the pretreatment-mediated fouling mitigation mechanism, is critical for controlling algal fouling. This study examined the fouling control mechanism of extracellular organic matter (EOM) by combined heat-activated potassium peroxymonosulfate (PMS) and polyaluminum chloride (PACl) treatment using extended Derjaguin-Landau-Verwey-Overbeek (XDLVO)-based interaction energy analysis. Results showed that combined PMS and PACl treatment effectively mitigated membrane fouling, with the fouling control performance being highly dependent on PACl dosage. PACl 5 mg/L under combined PMS treatment worsened membrane fouling, while PACl dosages 10 – 40 mg/L alleviated it, with the best performance achieved at 40 mg/L. XDLVO theory analysis revealed that PMS-PACl (10 – 40 mg/L) treatment enhanced repulsive membrane-foulant interactions and transformed membrane-foulants and foulants-foulants interactions from attractive to repulsive. Moreover, both membrane-foulant and foulant-foulant repulsive interactions increased with increasing PACl dosage. In contrast, although integrated PMS and PACl 5 mg/L weakened foulant-foulant attractive interaction than control EOM, serious membrane fouling was still observed, likely due to stronger attractive membrane-foulant interactions during the initial filtration stage. This research offers new mechanistic insights into fouling control and provides a theoretical basis for algal-laden water treatment. Download: Download high-res image (209KB) Download: Download full-size image