A method for regulating ion transport between first and second regions of a liquid solution containing ionic species in at least one of said first and second regions, the method comprising applying a voltage on an electrically conductive mesoporous carbon membrane situated between said first and second regions of the liquid solution, wherein liquid flow between first and second regions is permitted only through said mesoporous carbon membrane, and the applied voltage is selected to modulate the degree of ion transport between said first and second regions, wherein an increase in applied voltage results in a reduction in the degree of ion transport between said first and second regions, optionally up to a critical voltage at which ion transport ceases.