Assessing modified fouling index of ultrafiltration process in urban sewage treatment

Assessing modified fouling index of ultrafiltration process in urban sewage treatment

Membrane fouling remains a significant challenge in the ultrafiltration (UF) process, restricting the widespread application of UF membranes. Despite extensive research, more intuitive early warnings for membrane fouling and predictions of operating trends remain scarce. This study investigates the application of the modified fouling index (MFI) in the UF process for urban sewage treatment. The changing trend of transmembrane pressure difference in the UF process is consistent with the measured MFI results, and MFI also has a significant correlation with influent turbidity. This predictive capacity offers practical value for industrial process optimization, allowing operators to anticipate fouling risks and adjust pretreatment strategies before operational cycles commence. Key water quality parameters, including chemical oxygen demand (COD), total organic carbon, turbidity, MFI, ultraviolet absorbance at 254 nm, and three-dimensional fluorescence, were systematically analyzed. After treatment by the UF membrane, the effluent COD and turbidity were less than 30 mg/L and 1 NTU, respectively, meeting the Class IV surface water standard. Furthermore, the tested MFI trend aligns closely with theoretically calculated fouling index values, confirming that MFI can serve as a predictive indicator of membrane fouling potential in full-scale operations. These findings underscore the MFI’s significance as a robust parameter for influent water quality evaluation in UF systems. To enhance process reliability, we propose integrating real-time MFI monitoring into control strategies to dynamically optimize pretreatment protocols. This approach offers critical operational guidance for improving the long-term hydraulic stability and fouling mitigation efficacy of UF in municipal wastewater treatment applications.