How to avoid / treat bacterial growth in anolyte tank in CED system?

A. I do not know if someone has tried it before but then you can be the first one - try using a UV light to see if you can control the problem.

A. We have successfully removed the bacteria from our anolyte system by using silver nitrate.
Q. What are the required parameters we need to follow in our ED water base paint system to keep the anolyte system bacteria free?

A. To sustain your anolyte system free from bacteria then I would suggest that you must have to add biocide particularly Kathon by 0.2 to 0.3 % in anolyte tank on every weekend. Kathon can use for bacteria treatment even after paint in ED tank but hydrogen peroxide is not recommended to use in anolyte tank when the paint is there in ED tank.
Secondly you can drain the anolyte solution and fill the fresh RO water by deciding some frequency like maybe every 2 weeks or a month to remove any bacterial growth.

A. Bacteria formation can cause trouble in building high CED paint thickness with slightly orange peel effect; that can also reduce the paint gloss. Don't change the baking window schedule (temperature vs. time) -- it can give you worst results when your component goes to field exposure.

You said lower temperature baking is giving you satisfactory results. At what temperature are you baking and for what time? Have you checked its mechanical properties and salt spray test results?

A. I want to know first whether it is Cathodic Electro Deposition process? What paint are you using, and what is the by-product of this process. I can further answer only if I have this much information.

A. Just as alkalinity can retard the cure in a coating, an acid can speed it up. You probably have an acidic catalyst in your coating that is sensitive to the pH of the film. Adding acid to the mix would speed the cure, make it harder, and possibly lower the minimum temperature for curing. None of this is necessarily a good thing, it all depends on the properties of the coating and how they are effected by the cure cycle.

Why do you try to change the temperature instead of getting rid of the bacteria?

Ask your supplier how to get rid of it, he has the method for sure.

A. Hello, I am in no way an expert in this matter of anolyte so please allow for my ignorance on any matter - but the anolyte (and if I'm assuming correctly) is water based and something is growing in the anolyte and you can't or don't want to add any bleach or other.

Many years ago we developed an electrostatic water treatment system that we used on cooling towers and heat exchangers, etc.; it was very good at eliminating the need for fungicides. etc. But the propaganda from the chemical treatment industry killed us off - ha - we no longer operate in the business; it also removed scale from heat exchange surfaces and made it very difficult for fungus, etc. to find a place to breed (the main intention of our installations was to improve energy efficiency - ha - we were into energy management long before it became a 'hot topic'; unfortunately our enthusiasm was greater than the market readiness for our products (had some patents on other units).

Warmth/temperature of the anolyte, contamination from another area (ha -- hope none of the staff spitting in the tanks), scale/pitting etc, cleanliness are some of the things I'd be having a look at.

Also if the anolyte could have light passed through it -- maybe running it through a UV disinfection chamber could also be effective (I've used it to good effect in a water treatment plant we designed, built and commissioned in China in the mid 90s and the entire plant used zero chemicals -- although we used Katadyn silver treatment in the storage tanks, meaning we did not need chlorine to ensure there was no slime, mould, bacteria growth during the water storage phases).

Forgive my ignorance of your anolyte, but I hope maybe there is a "spark" in my comments that help you find a solution.

A. I recommend to not switch anolyte system. It should have continuous circulation, and once a week initially, and after that twice a month, hydrogen peroxide treatment to be done.

For CED paint maintain temperature and non-stop circulation. Also check pretreatment line and use process water after UV treatment.

A. Your paint supplier should be able to analyze a sample of e-coat to determine the ion concentrations in the paint.
As far as bacteria - There are slides that can be dipped in the paint or post rinse and incubated for three days. Bacteria will show up as red dots. This is easily done in-house.