The reported TpPa-75-250-2 membrane exhibits impressive antibiotic/salt selectivity and high water permeance under idealized single- and dual-component feed conditions. However, considering the reported pore size distribution (0.4–0.7 nm) and the negatively charged PAN substrate surface post-hydrolysis, how do the authors account for potential Donnan exclusion effects or electrostatic interactions between charged antibiotics (e.g., TC, ADR) and the membrane during filtration? Moreover, given that their separation performance was evaluated using low-concentration antibiotic/salt mixtures, how would the SAIP-fabricated TpPa membrane perform under more realistic high-salinity, multi-solute pharmaceutical effluents, where osmotic pressure gradients, competitive adsorption, and fouling dynamics may significantly alter permeation and rejection behavior?
I also have a question regarding this study. While the TpPa-75-250-2 membrane exhibits remarkable performance in terms of antibiotic rejection and water permeance under controlled lab conditions, I noticed that the permeation behavior and selectivity were primarily evaluated using low-concentration antibiotic/salt feed solutions (e.g., 50 mg/L antibiotics, 100 mg/L salts). However industrial pharmaceutical wastewaters often present far more complex and concentrated matrices with variable ionic strengths and organic loads.
Could the authors clarify how the TpPa membrane would maintain its selective transport behavior under high total dissolved solids (TDS) and complex organic environments? Specifically, has the impact of increased osmotic pressure, ionic shielding effects on electrostatic interactions, or the potential for organic fouling on the membrane’s performance (e.g., flux decline, selectivity loss) been considered or tested? Without such validation under realistic effluent conditions, how dothe authors support the industrial applicability of the reported performance metrics?