Peracetic Acid-Based Oxidation for Ultrafiltration during Natural Water Treatment: Significant Performance Enhancement and Novel Prediction Based on PARAFAC-EEMs Coupling Hydrophilicity Characteristic

Abstract

In this study, peracetic acid (PAA) preoxidation based on Fe­(II) and UV activation was proposed to mitigate the membrane fouling caused by natural organic matters (NOM) in surface water. Owing to the dual effect of oxidation and coagulation, Fe­(II)/UV/PAA preoxidation was an efficient alternative strategy prior to the ultrafiltration (UF) process, with a significantly improved membrane flux by 2.35 times and a remarkably lessened reversible fouling and irreversible fouling resistance by 95.6% and 95.7%, respectively. The degradation effect of naproxen (NAP) exhibited that the oxidation capacities followed the sequence of Fe­(II)/UV/PAA > UV/PAA > Fe­(II)/PAA > Fe­(II)/UV. Among them, the UV/PAA system with stronger oxidative capacity exerted superior removal of organics and irreversible fouling than the Fe­(II)/PAA system. For the first time, the PARAFAC-EEMs method was employed to monitor the degradation effect of oxidation on hydrophilic/hydrophobic (HPI/HPO) parts in NOM components and their influence on membrane fouling. It was found that R–C• produced by the UV/PAA process preferentially degraded C1HPI, C2HPI, and C3N‑HPO components, and the recalcitrant foulants that caused irreversible fouling in the Fe­(II)/UV/PAA system were small hydrophobic proteins. Moreover, the novel prediction of membrane fouling revealed that C1HPI had a higher correlation with irreversible membrane fouling than C1N‑HPO. There was a certain correlation between the irreversible fouling resistance and tyrosine-like proteins and a poor correlation with humics. Hence, the PARAFAC-EEMs method has a great potential for rapid detection and prediction of membrane fouling caused by the HPI/HPO parts of different fluorescent NOM components.

Progress of Ultrafiltration-Based Technology in Ion Removal and Recovery: Enhanced Membranes and Integrated Processes

“…The membrane stability is a key performance that affects the operational lifetime and economic feasibility. , Membrane stability (mechanical stability and chemical stability) is determined by the operating conditions, active materials, matrix, and the combination of active materials and matrix. Disruption of the active material and/or matrix leads to leaching of ions and reduces the additional functions (adsorption, electrostatic interaction, or steric exclusion) of membrane performance. , The loss of active material from enhanced membranes not only affects the efficiency of ion removal but also generates the secondary foulants into the wastewater.…”