RO Rejection Experiment - North West water quality

[Ian Wilde]

Thought I'd do a quick experiment with our RO units that spawned because we didn't know at what permeate output quality reading to start to be concerned at.

We took a raw water sample as a control and then sampled a selection of single patient RO units noting their input and output quality readings and from this worked out the ratio of rejection.

Turns out our water from the Lake District via United Utilities is pretty good anyway!

Comments welcome....

[Chris Bates]

Hi Ian,
Our regional raw water supplies would certainly fail a few of these limits looking at the water supplier test data.

Calcium and Magnesium obviously, but also Nitrates, Potassium and occasionally copper.

We start to worry when our permeate conductivity gets to 20-25 uS
Our normal incoming water conductivity is >750uS

Chris

[Ian Wilde]

Wow Chris - that is high!

Our highest is around 300uS.  Normally is around 100uS.