Caviation For Sanitation?

[TheCatcher]

I am in the process of relocating my pool filter and heater. I was thinking about switching out as much of the copper pipe as possible over to PVC, and possibly putting in a salt system.

Then I read this thread...

Caviation Sanitation post in a pipe leak thread

One of the answers mentions a pure tap water pool that successfully uses cavitation for sanitation.

I completely realize that the bubbles that people see in their pool motor's debris filter are probably not cavitation bubbles, they are typically (if not always) just air being sucked in through very small leaks in the pipes or in the seal of the debris filter lid.

Cavitation for sanitation sounds very attractive, since I wouldn't need to replace my copper pipes... And the pool chemistry maintenance would probably be a little more tolerant of my lack of attention.

Here are my questions...

Does cavitation really work? Logically it seems like it should kill most, if not all, micro-organisms. I doubt that there are many micro-organisms that are strong enough to withstand enough of a vacuum to almost instantly turn water to gas...

If cavitation does really work, what are the numbers involved? How much area and for how long would the water need to be exposed to the cavitation? And how much of a vacuum would need to be generated? Just enough to turn some of the water to gas, or does it need to be most of the water to gas? I would guess just some of the water to gas would be enough of a vacuum to destroy the micro-organism cell. Since I suspect if they have any gas in them at all, they will experience the bulk of the explosive decompression.

Does the cavitation need to be impeller generated cavitation (potentially expensive to operate, and probably prone to leakage), or could I use piezo / sound generated cavitation? I'm hoping it can be piezo / sound generated cavitation. I have experience designing and implementing underwater PicChip piezo systems. So generating a cavitation environment via a piezo plate or tube should be easy and inexpensive.

[chem geek]

Scientific papers such as this one, this one and this one indicate that at best it could be used as supplemental disinfection, but even if it were perfect at killing every microorganism that passed by, it would still be limited by circulation time and would do nothing to affect biofilms on pool surfaces. This is why a bulk-water disinfectant is still required. So basically, you can look at this as really no better than UV, ozone or any other supplemental system in the circulation path except that some systems are also oxidizers while cavitation is not (so it does not break down bather waste, for example).