On-Line Monitoring of Ultrafiltration Membrane Fouling Based on EIT Sparse Imaging

Online understanding of the membrane fouling development status is of great significance to further improve the water treatment process. Problems such as low efficiency, difficult operation, and radiation hazards limit the development of existing detection methods. An online monitoring method for in situ ultrafiltration (UF) membrane filtration based on electrical impedance tomography (EIT) is proposed. The electrical sensor array is designed for flat-sheet membranes. The planar electrode array is designed to monitor the development of membrane fouling in real-time. Based on the local sparsity of UF membrane fouling distribution, the conductivity distribution of membrane fouling is reconstructed by the group sparse-based EIT imaging algorithm. The filtration characteristics for different concentrations and different types of solutions are explored through dynamic EIT imaging. According to experimental results, the accumulation of membrane fouling under different filtering conditions can be visualized through local conductivity distribution from the EIT images.