Looks like significant ...

Published August 12, 2019 14:45 by Kai Hoehn, General Manager

Looks like significant fouling ( iron?) on the membrane have caused high differential pressure and subsequent telescoping. Chances are high that you need a new set of RO elements.

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The membrane used to suffer from uf collapse (upstream), and a lot of bio-sludge got stuck NF membrane chanel. It happended last Mar. 2018. The contractor cleaned it by water hose from permeate port. Then they reloaded and put it back into operation till i inspected last week.

Thanks for for answer!

Hieu

Published August 15, 2019 11:58 by Hieu Nguyen, WWTP supervisor at Vietnam Waste Solutions

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3 Comments

Thank you for all your replies. How bad it is if i keep using it. And how long does it last?

The contractor cleaned the element with fresh water @3bar. I also warned them on the damages when reversing flow from permeate port.

Published August 21, 2019 12:24 by Hieu Nguyen, WWTP supervisor at Vietnam Waste Solutions

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Pierre Dreher You are absolutely right, but please emphsis that the problem of membrane collapse is due to sudden high-pressure supply (start-up) on the clogged membranes and was ignored.

Published August 17, 2019 18:08 by Sameer Dohare, Managing Director at EnviroChem Services (OPC) Pvt. Ltd.

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These membranes should have been chemically cleaned/treated. When you have fowling as you have, you can not clean the membranes by just flowing water from the permeate port, which is probably the cause of the damage.
There are ways to clean the membranes by reversing the flow through the permeate ports but not advisable if you do not know how to do it. Reversing the flow in these types of membranes (RO or Nano) is tricky.
Do you know at what pressure the contractor used to clean the membranes?

Published August 15, 2019 17:57 by Pierre Dreher, Founder at 18.01528 Consulting

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