Clearly, as n increases, a systematic exchange of NO - 3 and Cl -densities on the piston wall can be found, with NO - 3 remaining closer to the wall as compared to Cl -ions. During this transition, NO - 3 ions are attracted to the polymers and become localized on the B-blocks, while Cl -ions are distributed throughout the solution, with higher intensity near the piston wall. The schematics also show that Na + ions are more populated in the feed reservoir in the presence of higher Cl -levels (higher n) and are less transferred into the permeate. Indeed, this behavior can be attributed to the blockage of membrane pores by adsorbed molecules. Polymer coverage of the membrane surface can reduce the degradation rate caused by chlorination, which is a major limitation of membranes.