Hi
Regarding CO2 depletion of mixed bed for a small system the easiest way is to use a softener instead of antiscalant and to dose caustic.
Other solutions exists (degassing membranes) but they will be over expensive.
Hi
Cationic resins are pretty sturdy stuff.
They can swell if they see too much chlorine, but it takes some time usually and you said that the change was abrupt
It would point out to some ingress of suspended matter.
Hi Ajz
To determine what you can get out of the unit, you need to provide a detailed (as much as possible) water analysis.
Please add any pretreatment you may use before the RO (sand filter, decantation, softener)
This will help determine the scaling potential of the feed water and we could...
Do some flow normalization (there are spreadsheet available from membranes suppliers. When normalized flow decreases of 15% or norm pressure drop climbs 15 % it is time to clean.
Hi
There will be negligible water loss thru the degasser (the water/air flows are not comparable to a cooling tower plus the water is not hot (normally)). There may be some small losses with mist generation but really not a lot, 1% would be a max.
However as other have pointed out, there is...
@Laefranz
For Fujiwara test check for instance
http://www.membrane.unsw.edu.au/wp-content/uploads/Vis-Inspection.pdf
As for rejection enhancer, I think that Kurita (ex BKGiulini) used to have some specialty for that. It should be some tannin containing formulation that "coats" or adsorbs on...
Hi
Yes, it sort of confirms my first impression. Your water is not very hard (50 ppm as CaCO3) and so a combination of anionic resin and softening resin could give some good results. I know only of 2 Resin suppliers in India Ion exchange and Thermax, but for a small application like this you'll...
Hi Sujith
It is difficult to give an precise opinion with so little data. Do you have some more water analysis ? By which method did the WT company remove the iron?
As for resin causing irritation, it depends on what you are regenerating the resin with. If you use salt to regenerate a softener...
Hi Sujith
there are specialized resins for tannin removal. They are usually weak base resins and can be cleaned quite efficiently.
Look up for "organic scavenger resin", some manufacturers have specialized ion exchange resins to do that which can be regenerated with salt insted of caustic soda...
It is true that the symptoms can lead to think about membrane oxidation, so you can do a fujiwara test to check for membrane oxidation. There are some chemical treatments to try to get some rejection back, mainly based on Tannin molecule (from memory). I have never tried them so I cannot comment...
As for the resins, cationic resin will be OK as long as the concentration is not too high. I'm more reserved about anionic resins as they will oxidise more easily. You risk losing some strong capacity which is important for capturing weakly ionized species as CO2, SiO2 and Boron. Thereis also...
During the test we made in a dairy application ( reuse of "cow water" from milk evaporation condensate) we were working @ 1 ppm equivalent Cl2. I was first surprised to see that rejection was not affected. The test lasted for something like a month. So I think that a low residual can give good...
or it may precipitate - depends widely on pH and presence of oxidants including Oxygen
http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0042/0901b80380042b91.pdf?filepath=liquidseps/pdfs/noreg/609-02042.pdf&fromPage=GetDoc
