Ro membrane failures

[jeff williams]

I’m having terrible problems with the filmtec ro membranes that BRS sells. The membrane fails in 5-6 months like clock work. When I unroll the membrane there is cracks in the film. I’ve tried everything I could think of and BRS has been very helpful in trouble shooting the problem. I’ve tried changing the carbon block every few months, I’ve contacted my water management office and they tell me only a small amount of chlorine is used, no chloramines are used, even when the membrane has failed the is no trace of chlorine in the product water. The membrane is not drying out between use and the supply water has been tried @50 to 60 psi and cool water not warm or hot. Keep in mind in this 5-6 month time I’m only making about 150-200 gallons of water.
my tds runs 350-450
With all new filters and membrane the tds will be as low as 8-15 going into my DI.
as the membrane fails the tds going into the DI increases rapidly

my question is, is anyone else having this problem with these membranes? And is there any other suggestions you might have to correct the problem?

 

[HuduVudu]

I’m having terrible problems with the filmtec ro membranes that BRS sells. The membrane fails in 5-6 months like clock work. When I unroll the membrane there is cracks in the film. I’ve tried everything I could think of and BRS has been very helpful in trouble shooting the problem. I’ve tried changing the carbon block every few months, I’ve contacted my water management office and they tell me only a small amount of chlorine is used, no chloramines are used, even when the membrane has failed the is no trace of chlorine in the product water. The membrane is not drying out between use and the supply water has been tried @50 to 60 psi and cool water not warm or hot. Keep in mind in this 5-6 month time I’m only making about 150-200 gallons of water.
my tds runs 350-450
With all new filters and membrane the tds will be as low as 8-15 going into my DI.
as the membrane fails the tds going into the DI increases rapidly

my question is, is anyone else having this problem with these membranes? And is there any other suggestions you might have to correct the problem?

I am using the BRS membranes. I am well past 6 months and I make about 60 gallons per month and a half.

Are you making the water all at once or are you making on demand.

I make ~60 gallons at a time.

 

[KStatefan]

What is your waste to product ratio? Do you have a water softener?

 

[flyfisher2]

I had my Ro unit out side and the temperature and or the membrane housing were factors. Once I brought the unit indoors the issue was solved. My membrane is over a year old and I produce over 240 gals per month.

 

[jeff williams]

I am using the BRS membranes. I am well past 6 months and I make about 60 gallons per month and a half.

Are you making the water all at once or are you making on demand.

I make ~60 gallons at a time.

All at once

 

[jeff williams]

What is your waste to product ratio? Do you have a water softener?

Yes on water softener and my rejection rate is what BRS suggested I use their 550 choke

 

[BZOFIQ]

Try a membrane from Spectrapure and see if results differ.

If not, then you know something on your end is causing the failure.

 

[BZOFIQ]

What is your PSI pre-membrane?

 

[KStatefan]

Yes on water softener and my rejection rate is what BRS suggested I use their 550 choke

Have you measured the ratio to see what is actually is?

 

[jeff williams]

What is your PSI pre-membrane?

50-60 psi I’ve tried it at 60 for a long time with no improvement and went back to 50

 

[jeff williams]

Have you measured the ratio to see what is actually is?

Do you mean the rejection ratio? No I have not checked that I just installed the choke BRS suggested with that membrane

 

[rajdude]

Do you mean the rejection ratio? No I have not checked that I just installed the choke BRS suggested with that membrane

I think he is talking about the ratio of water going down the drain vs the output (permeate)

 

[rajdude]

This is an interesting problem. I did a quick search and this came up. You may want to take a look at the photos there.
Do the cracks in your membrane looks like that?

Understanding the operational problems and fouling characterization of RO membrane used for brackish water treatment via membrane autopsy | Water Science & Technology | IWA Publishing

HIGHLIGHTS. An autopsy of spiral wound RO membrane operated in brackish water treatment was conducted to understand the fouling behaviors.Various instrumental a

iwaponline.com

(Long article, go to that page and search text in the page for crack)

I have heard from sources on the internet, that rapid on-off of water input is not good for our RO membranes, but this is the first time I have heard someone's membrane cracking!

I quote them (I added the red color)

RESULTS AND DISCUSSION​

Evaluation of visual inspection of RO module and membrane​

Listen

Firstly, the physical examination of the spiral wound RO module brought to the laboratory was performed, and no physical damage was observed in the feed and permeate channels. However, when the outer protective shell of the module consisting of fiberglass was examined, it was determined that some part of the protective shell was cracked. The fiberglass membrane cracks in the outer shell have several causes. When the membrane system is stopped, the air remaining in the membrane or pressure cover causes cracking of the fiberglass material due to the sudden rise in feed water pressure while the system is restarted. Therefore, the feed water pressure should be increased gradually to prevent the formation of cracks. Another reason for damage to the protective fiberglass cover is the high pressure drop caused by membrane contamination. Thus, the pressure difference between feed and concentrate stream above the limit values should be avoided. The images of RO module, feed and permeate stream channel, and the crack detected on the fiberglass cover of the module, are given in Figure 1.

Also was able to add that image here....