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# Program Ph Of Ro Water

9 replies to this topic
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### #1 Albertox

Albertox

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Posted 09 January 2019 - 06:13 AM

Hello, i am working on my desalination plant proyect and i am having problems on calculate the pH of the fresh water right after the RO module.

I have tried with some Programs like Rosa FilmTec but everyone force me to use a membrane with the characteristics. I would like to know if there is a program where i can select the salt reject i want or if there is a program where i can select the concentration of the anions and cations and tell me the pH.

Thanks you very much

### #2 thorium90

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Posted 09 January 2019 - 06:27 AM

If you just want to calculate the pH due to ions for a specific chemical...

http://www.endmemo.com/chem/phcal.php

If you just mean the pH from the H+ concentration...

Although, fyi,  the projection softwares calculate the pH of the water, reject and permeate automatically... Its already inside ROSA...

If you mean something else... do clarify...

Edited by thorium90, 09 January 2019 - 06:27 AM.

### #3 Albertox

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Posted 09 January 2019 - 06:40 AM

I have the anions and cations of the feed seawater and I want to reject the 98,2% of all the anions/cations and know the pH of that fresh water.

So I dont know if its possible to introduce the cations/anions of the fresh water and calculate the pH.

K = 8,7

Na = 202,01

Mg = 26,72

Ca =8,66

Sr = 0,216

Ba = 0,00018

Cl = 372,96

F= 0,02

SO4 = 53,46

SiO2 = 0,04

B = 0,08

Everything in mg/l

So i want to know the pH of the water with that anions/cations

I dont know if i am explaining clearly, English is not my main lenguage.

If that choice is in ROSA please tell me where because i didnt find.

Edited by Albertox, 09 January 2019 - 06:58 AM.

### #4 breizh

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Posted 09 January 2019 - 07:30 AM

Hi ,

Why don't you email to Dupont Tech Service ? They should be happy to support .

https://www.dupont.c...er/support.html

note : probably good to review the concentration ! mg/l?

Good Luck

Breizh

Edited by breizh, 09 January 2019 - 07:39 AM.

### #5 Albertox

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Posted 09 January 2019 - 07:39 AM

Thank you very much

Whats the problem of having the concentration on mg/l?

Edited by Albertox, 09 January 2019 - 07:47 AM.

### #6 breizh

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Posted 09 January 2019 - 08:26 AM

hi,

the figures look  small, considering sodium and chloride for sea water ! NaCl should be about 3.5% mass .

my 2 cents

Breizh

Edited by breizh, 09 January 2019 - 08:35 AM.

### #7 Albertox

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Posted 09 January 2019 - 09:01 AM

K, Mg, Ca and SO4 have too much concentration to be honest, but the Na and the Cl concentration is properly for fresh water.

I am wrong Na and Cl should be less than 200 and 250 respectly.

Edited by Albertox, 09 January 2019 - 09:14 AM.

### #8 thorium90

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Posted 09 January 2019 - 10:54 AM

### #9 Albertox

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Posted 09 January 2019 - 11:06 AM

You are not understanding my problem. I already know the concentration of cations and anions after the RO module without using ROSA. The only thing i want to know it's whats the pH of the water with that concentration.

Probably I dont need ROSA for this but i dont know how can I do.

### #10 thorium90

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Posted 09 January 2019 - 10:02 PM

The pH of the water is already shown in the last row of the projection. I made a sample and put a red box around the row called pH.

If you are asking about the feed water pH, then that is defined when you do a feed study. For example, by taking past data and taking an average.

Edited by thorium90, 09 January 2019 - 10:04 PM.