As an aside, I have (had) always found the water treatment side of dialysis very interesting; although my own involvement (a very long time ago now, Neil - and even before we met) was in support of a number of small AKU's in desert locations.
I recall lots of pump failures and so forth (simple stuff, but inexcusable really). As you must remember, the incoming water supply from the baladiya
was often of "poor" quality and sometimes intermittent; I seem to remember on occasion having to bring in tankers (trucks) full of so-called "sweet water". All a bit ad-hoc
perhaps, but it was very much "needs must" at the time.
I don't remember any UV sterilization in those AKU's, though. If I remember rightly (and I may still have my old notebook - the pen and paper type, that is) it was all done via
Reverse Osmosis (Permeator?); but I seem to recall "salts" (softener?) being involved as well. Also a storage tank, of course - and a 5 micron (I think it was) filter before each of the dialysis units. All a bit crude back then (and there), no doubt.