Fig. 4: Membrane selectivity and fouling behavior.

A Water permeance and water-boron selectivity for the TIP membranes (colored circles) compared with literature data (grey squares). All the relevant data and references have been summarized in Supplementary Table 4. B Water permeance and water-As (III) selectivity for the membrane prepared in this study (colored circles) compared with literature data⁶³ (grey squares). All data was obtained from the filtration tests under crossflow conditions at a neutral pH of 6-8. All the relevant data and references have been summarized in Supplementary Table 5. C Normalized flux of TIP25 and TIP100 membranes during a fouling-cleaning test over 50 h. Normalized flux is the ratio of the water flux at time t (J_t) over the initial water flux (J₀, 15 L m⁻² h⁻¹ in this study). The fouling test was performed using a feed solution of 0.1 g L⁻¹ HA and 2 g L⁻¹ NaCl at pH7 for 48 h. During the fouling tests, the initial flux J₀ for both membranes was kept the same (i.e., 15 L m⁻² h⁻¹) to ensure a fair comparison of fouling behaviour^64,65. To achieve this initial flux, the applied pressure was approximately 13.6 bar for TIP25 and 8.3 bar for TIP100. The fouled membranes were cleaned with DI water, followed by the filtration of 2 g L⁻¹ NaCl under the same pressure for 2 h. D Flux reduction and HA accumulation for TIP25 and TIP100 membranes after a 48-h fouling test. The error bars represent the standard deviation obtained from at least three independent measurements of different membranes.