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19 comments
Participant

Join Date: Apr 2008
Posts: 3

Electrolysis Test of water

04/16/2008 2:17 AM

After electrolysis test of different samples of water the colour of water changes to

either Red & Yellow or Black or Blackish Green or Blue or only Yellow.

Could you please tell me why it is so. And which among the above is fit for drinking.

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Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

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#1

Re: Electrolysis Test of water

04/16/2008 7:50 AM

It is not normally necessary to apply electrolysis to determine potability. Please supply details of the test.

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Participant

Join Date: Apr 2008
Posts: 3
#3
In reply to #1

Re: Electrolysis Test of water

04/17/2008 4:05 AM

Dear Mr. PWSlack,

Hello!

Thanks for answering my question.

For Electrolysis Test two rods one Alimunium and other Iron were dipped in water samples and electric current was passed thru them for generation of Heat. The expriment was done for one minute. Water in the containers also got heated up and colour change was visible.

Waiting to hear from you.

Regards'

Deepak Raina

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Guru
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#5
In reply to #3

Re: Electrolysis Test of water

04/17/2008 7:58 AM

'Potable' is a term usually used to describe water that has a conductivity below World Health Organisation guidelines for drinking water (normally 1000μS/cm or so at everyday ambient temperatures) and having a virtual absence of certain viable bacteria.

'Electrolysys' is a term used to describe the decomposition of materials under the influence of an applied electric current.

There is no overlap between there terms, and the test as described here cannot readily be applied to determine potability.

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Guru
Engineering Fields - Retired Engineers / Mentors - New Member

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#7
In reply to #5

Re: Electrolysis Test of water

04/17/2008 8:50 AM

Agreed. Never heard of an electrolysis test for measuring the potability of water. We are missing some critical piece of information here.

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Guru
Engineering Fields - Environmental Engineering - New Member APIX Pilot Plant Design Project - Member - New Member

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#2

Re: Electrolysis Test of water

04/16/2008 10:52 PM

What reagents did you use? Electrolysis normally does not change the color of water. In fact, it's sometimes used, in the form of electrocoagulation, to purify water. Black normally indicates the presence of sulfides, while blue or green indicates the presence of copper.

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Participant

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#4
In reply to #2

Re: Electrolysis Test of water

04/17/2008 4:08 AM

Dear Mr. Dvader,

Hello!

Thanks for answering my question.

For Electrolysis Test two rods one Alimunium and other Iron were dipped in water samples and electric current was passed thru them for generation of Heat. The expriment was done for one minute. Water in the containers also got heated up and colour change was visible.

Waiting to hear from you.

Regards'

Deepak Raina

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Guru
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#11
In reply to #4

Re: Electrolysis Test of water

04/18/2008 12:00 AM

Concur with Eriew on the colors. Red indicates iron, black manganese or sulfides (although sulfides will usually be accompanied by a foul odor), green or blue copper.

Since you are not using any reagents, very likely the color froms from precipitated dissolved metals. The red color may have come from your iron terminal or the water itself. By carrying out your test, you have probably electrocoagulated out the dissolved metals.

Are there any metalwork or plating plants upstream of where you collected the sample from? If there is, the water may be contaminated by discharge from the plants, which means it will not be potable. If not, then your water sample has a very high dissolved mineral content. Which part of India are you in? If you're in the Bengal region, better get a lab to test the water for arsenic as well.

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Associate

Join Date: Jul 2013
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#19
In reply to #11

Re: Electrolysis Test of water

07/04/2013 1:12 AM

How can we post images and videos? I want to have a complete list of colours corresponding to different chemicals dissolved, that one may get on electrolysis of water? Coversely if you can give the link, it will be helpful.

By the way, what made the community members think that my question is related to HOMEWORK. I am amazed.

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Power-User

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#6

Re: Electrolysis Test of water

04/17/2008 8:18 AM

What color was the raw water before you played with it? Are you in a soft water or hard water area. Is the water source a well or surface water (i.e. lake).

For soft water from wells

Red = iron

Black = mangenese

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Guru
Popular Science - Weaponology - Cardio-7

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#9
In reply to #6

Re: Electrolysis Test of water

04/17/2008 10:26 AM

Red = iron; Black = manganese. Any of the colors that the gentleman from India (?) is stating he finds from water electrolysis likely mean that the water is definitely not potable! It's also possible that the dead microbes and bugs in the heated water may be causing the color. I'd suggest treating a gallon the the "water" with a small amount ( 1/2 teaspoon per gallon) of bleach ( 5 % solution of sodium hypochlorite, NaOCl) or a very small crystal of Iodine, and leave the treated water sit overnight, then see what it looks like. There will likely be a fairly large deposit of white "organic matter" on the bottom. Now see what colors your electrolysis produces, decanting the clear water, and using clean rods.

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Guru
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#8

Re: Electrolysis Test of water

04/17/2008 9:25 AM

If you have the time and patience:

-dig into all kinds of data linked to ElctroCoagulation = EC

EC was discussed a lot in CR4

EC is the most effective way to get rid of:

  • OIL/GREASE
  • Bacteria/Algae
  • Solids Suspended/Dissolved--Polar/nonPolar-- Hence all colours
  • Smell/Smack

After separating all above into 3 phases

-lighter scum held afloat for hours by tiny gas bubbles

- Middle Clear water 95% column height

- Separated Hydroxides of all colours + dead life forms clinging to these-- lying settled at bottom

You take out the middle sweet aerated water; better than "Expensive Mineral Water":

And drink the same without fear and be healthy again.{ No chemicals were/need- be added}

maybe you should visit www.innovation2survive.com

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Participant

Join Date: Mar 2011
Posts: 1
#18
In reply to #8

Re: Electrolysis Test of water

03/22/2011 1:43 AM

Was searching for this topic on the Net after a sales person of a Water Purifier company did this little 'electrolysis test' with hard water and municipal water at my home then and chanced upon this thread. I really wanted to know if these 'tests' are normally used or is this just some peddler's play upon a naturally occurring phenomenon when electrolysing water of such quality. He said he was using iron and aluminium electrodes in both cells and when the current was passed, noted that the hardwater sample bubbled furiously and heated up considerably (possibly to 70-80 deg C) -as a result of 'flourides' said the salesman. It also acquired a florid green-blue tinge (as a result of 'bacteria and organic matter' said the salesman) around the top, which slowly subsided as the water cooled down. The municipal water, on the other hand, acquired a yellow-brown tinge and did not heat up as much. The yellow slag-like mush also slowly sank to the bottom after some time. Noted some yellow bubbles in both water samples (coloured like iron rust powder). Can someone point out relevant resources to read this up on the Net? Thanks. Regards, Welingkar

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Guru
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#10

Re: Electrolysis Test of water

04/17/2008 2:55 PM

OK, got the iron and aluminum rods used for electrodes. You refer to this as an 'electrolysis test' - what are the test parameters?

Got the color change, but is it the water itself that changes color?

Is the color appearance faint or 'dense'?

You do not mention the source of any of the water samples, where is each from in relation to the color change?

Were any other chemical reagents used in this 'test'?

Any other possibly pertinent details?

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Participant

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Posts: 1
#12

Re: Electrolysis Test of water

12/22/2008 11:46 PM

Hi!!

RO Plant Sales guys came and took samples of our Mineral water, Tap water and did the same electrolysis process (as explained in this thread above). The water (both) had a Black layer on top of the surface which settled at the bottom after some time as soot/sediment. This is how they justify that their RO plant shall be installed to avoid consuming this "poison".

What can this be???

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Guru
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#13
In reply to #12

Re: Electrolysis Test of water

12/24/2008 8:10 AM

Keep in mind that the RO sales guys' objective is "sales". Only a good laboratory analysis can tell you for certain what it "is". What it "could be" ranges from roasted bacteria to coagulated minerals.

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Anonymous Poster
#14

Re: Electrolysis Test of water

05/29/2009 11:10 AM

Dear sir, In Electrolysis test the colour change of water is depends on elctrodes. Example: iron,copper,aluminium..etc When we use the aluminium electrode the water colour is not change. when we use the copper electrode the water colour change into brown colour. So,this test not satisfy the purity of water..

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Anonymous Poster
#15

Re: Electrolysis Test of water

09/13/2009 5:13 AM

What is the significance of this qualitative test in water potability?

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Anonymous Poster
#16

SAME TEST BY AN RO SALES GUY AT MY HOUSE> DETAILS AS BELOW

04/10/2010 1:08 AM

SAME Thing happened at my house. I can give some clarity on the test. The RO sales guy asked for 2 glasses of water, one tap water, one filter water. Placed a water electrolyzer with aluminium and iro electrodes and pass current for a minute. Both glass water was warmed up and yellow and green colour visible and some brown and greenish black solids appeared. He said a bottled mineral water would not have this effect. So i got a glass of mineral water. Although there was a slight yellow colour appearence, there were no solids formed. He also had a TDS tester and our filter water showed 140 ppm. whereas mineral water had 38 ppm. Should i beleive that my filter water is unsafe for drinking.

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Anonymous Poster
#17

Re: Electrolysis Test of water

01/17/2011 10:53 AM

The electolysis demonstration shows that there are minerals in your water - it does not show if those are good or bad minerals for human consumption. The sales person will be using a water that is completely free from minerals, so it does not turn black or heat up. Check youtube for a good video demonstrating this.

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Users who posted comments:

agua_doc (1); Anonymous Poster (4); Cardio07 (1); derbahul (2); DVader1000 (2); EnviroMan (2); kpankaj (1); MUKULMAHANT (1); PWSlack (2); Subhasankar (1); user-deleted-9 (1); Welingkar (1)

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