A two‐stage modified PES ultrafiltration system for enhanced treatment of high‐strength seasoning wastewater: organic removal and process optimization

BACKGROUND The treatment of high‐strength industrial wastewater containing high organic load and salinity remains a significant challenge for conventional processes. This study presents an integrated two‐stage ultrafiltration (UF) system based on modified polyethersulfone (PES) membranes specifically developed for seasoning wastewater treatment to simultaneously address organic pollutant reduction, biofouling, and partial desalination. RESULTS In the first stage, the membrane surface was modified with dopamine (DA), polyethyleneimine (PEI), and silver nanoparticles (AgNPs). An optimal 1:1 DA:PEI ratio yielded a flux recovery ratio of 88%, while the incorporation of AgNPs provided distinct antibacterial activity against Shigella flexneri. Additionally, artificial neural networks (ANNs) accurately modeled flux decline with a high predictive accuracy (R2 = 0.964). The second stage, utilizing a glutaraldehyde‐crosslinked PES membrane, achieved 53.12% Ca 2+ rejection compared to only 6.53% for Na + , which was primarily driven by Donnan exclusion. Overall, this integrated two‐stage system achieved 92.27% chemical oxygen demand (COD) removal. CONCLUSION The proposed integrated two‐stage modified UF system demonstrates effective fouling mitigation, robust antibacterial functionality, and successful selective multivalent ion removal. These findings highlight the system's strong potential as an energy‐efficient treatment or selective pretreatment process for high‐strength, high‐salinity industrial effluents.