Optimization, flux kinetic, and thermodynamic analyses of the photocatalytic PSf/CTS membrane for phenol removal in petroleum wastewater treatment

Photocatalytic membranes have become a highly popular research topic recently, leading to the discovery of numerous new photocatalysts, methods, and perspectives. However, many studies have been predominantly based on a “one factor at a time” approach, lacking a comprehensive understanding of the multivariable interactions occurring in processes related to photocatalytic membranes. In this study, a comprehensive discussion is presented on the optimization of operational conditions, including illumination conditions, operating pressure, feed type, and membrane type, in the filtration using PSf/CTS membranes for the first time. Statistical analysis results indicate that the modified cubic model is the most representative in describing the interactions between independent variables and responses. Optimization tests reveal that the ideal conditions for photocatalytic membrane processes involve the use of PSf/CTS membranes, an operating pressure of 800 kPa, phenol as the feed type, and UV irradiation. It resulted in a flux of 41.385 L·m−2·h−1, phenol rejection of 67.735 %, and the fouling resistance at 9.12 × 10−11 m−1. The developed flux model effectively depicts the flux profile of PSf/CTS membranes with the smallest sum of squared error at 40.97. Thermodynamic analysis of the PSf/CTS membrane surface indicates that antifouling phenomena occur due to the substantial energy barrier between the surface and foulant, due to the CTS sites. The findings of this study provide new insights into photocatalytic membranes, focusing on multivariable interactions, kinetics, and thermodynamics. In a broader perspective, the study's results can serve as a reference for other membrane system investigations, contributing to the continuous development of membrane science and technology.