The short answer: yes, and irreversibly. Membranes have a low tolerance to chlorine and the damage cannot be undone by cleaning.
Reverse osmosis membranes have a notably low tolerance to chlorine. Where free chlorine in the water exceeds 1 ppm, the membrane is damaged.
That damage differs from fouling in one important respect: fouling can be removed by cleaning, chlorine damage cannot. A damaged membrane has to be replaced.
With chlorine damage the membrane loses its ability to retain. The result appears as a simultaneous rise in production flow and in permeate conductivity — the system produces more water, but the water is of lower quality.
A rising flow may look positive at first; read without conductivity alongside it, this symptom is easily missed.
Chlorine is already present in mains water for disinfection purposes; the problem is not that chlorine exists but that it reaches the membrane. Free chlorine must therefore always be removed from the water ahead of the membrane.
Skipping that stage in the pretreatment arrangement means leaving the most expensive consumable unprotected.
Membrane replacement is decided by data, not by the calendar. The five indicators we look at in the field and what each of them means.
View →If hardness appears early at the softener outlet, the problem usually lies not in the resin itself but in the water reaching it and in the regeneration settings.
View →In cooling water it is usually unnecessary to filter the full flow. The points that decide between side-stream and full-stream filtration.
View →Membranes are delicate structures and the cause of fouling is not always the same. The fouling we see in the field falls into three main groups; the remedy changes with that distinction.
View →Read flow and conductivity together and they point to the source of the damage with surprising clarity. Three typical patterns and the problem each one indicates.
View →The cleaning decision looks not at the calendar but at three measurements: differential pressure, permeate conductivity and production flow. The threshold values, and what to do after a long shutdown.
View →Silica is one of the most dangerous minerals for a membrane and it occurs in water in two different forms. The precaution differs for each.
View →An antiscalant is chosen from an analysis, not from a catalogue. The two decisive parameters, and why the projection calculation must not be skipped.
View →Activated carbon and SMBS dosing are the two ways of neutralising free chlorine ahead of a membrane. When to prefer which.
View →Let us size the system together; we will survey the site in person if needed.
