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Unregistered
01-28-2010, 02:02 PM
What is the best way to calculate the amount of a liquid chemical (lets say chlorine) needed to raise the chlorine level in a given amount of water to reach a needed PPM? For example how many gallons of chlorine (at 13%) do I need to add to a body of water (5000 gallons) to raise the PPM to 50 PPM.

JohnS
01-28-2010, 02:32 PM
What is the best way to calculate the amount of a liquid chemical (lets say chlorine) needed to raise the chlorine level in a given amount of water to reach a needed PPM? For example how many gallons of chlorine (at 13%) do I need to add to a body of water (5000 gallons) to raise the PPM to 50 PPM.

About 2 gallons. The method below is approximate as I don't know the density of your stock chlorine solution, but it is close enough.
13% is 130000 ppm, you want 50 ppm or, to dilute it 2600:1. You have 5000 gallons, 5000/2600 = 1.9 gallons, which I would just round to 2.

Unregistered
01-29-2010, 06:47 AM
Thank you so much for the reply. So it sounds like to get my gallon amount of chlorine (if my % is constant, which it is) I will continue to just divide the amount of water (in gallons) by 2600.

JohnS
01-29-2010, 10:29 AM
Thank you so much for the reply. So it sounds like to get my gallon amount of chlorine (if my % is constant, which it is) I will continue to just divide the amount of water (in gallons) by 2600.

If this is a pool or something similar. the chlorine level will often have not gone to zero before you add it again. If the level were at 20 ppm for example, and you wanted to elevate it to 50 ppm, you would only add enough for a delta of 30 ppm. However, you could work that the same way.

Legionella Control
02-06-2010, 04:36 PM
Although your concentration is stated as 13% you should take the value to be nearer 10%.

The idiots rule of thumb (bucket science) is to add half a litre of chlorine to 1000 litres of water to achieve 50ppm.

You need to take into account factors such as ph and cleanliness of the system, a higher ph will require more chlorine and starts to go up in a logarithmic scale, so best to add something to neutralise the ph of the water if you have something from ph 8 - 9. You should not proceed to chlorinate water with a ph value of 9 without correcting the value.

Similarly, a low ph Value should be brought up to between 7 and 8.

This heavily chlorinated water will be dangerous to all users of the system, so it is best to have the buiding empty when carrying out any work.

Also please note, I am not sure what you intend to chlorinate or why, but be aware chlorine only achieves a 'contact kill', ie it will not penetrate or dissolve dirt, scale etc which will be harbouring bacteria. If this is your aim, you should try something like hydrogen peroxide or chlorine dioxide, if the system has heavy calcium deposits you may want to try an acid clean first too.

Any questions contact me through my website.

Martin

legionellacs.co.uk

Unregistered
05-18-2010, 08:39 AM
Dear Martin,

I have an enquiry. How do I calculate the ppm of chlorine in sodium hypochlorite,NaOCl if the percentage of the NaOCl is given, let say 3%?

Following is the method that I used to get the % NaOCl:
1. Weigh 1g of sample (Scrubber waste sample)
2. Add 25mL of Deionised water.
5. Titrate with Sodium Thiosulphate 0.1M until colourless.

Formula of %NaOCl = (V X 1.0N 0.003546) X 100 / weight of sample

Mrs X
05-18-2010, 10:32 AM
Dear Martin,

I have an enquiry. How do I calculate the ppm of chlorine in sodium hypochlorite,NaOCl if the percentage of the NaOCl is given, let say 3%?

Following is the method that I used to get the % NaOCl:
1. Weigh 1g of sample (Scrubber waste sample)
2. Add 25mL of Deionised water.
5. Titrate with Sodium Thiosulphate 0.1M until colourless.

Formula of %NaOCl = (V X 1.0N 0.003546) X 100 / weight of sample

Hi, After step 4, are you diluting to a known volume in a volumetric flask, for example does it say "make up to 100mL"? - This should be an included step if not. :)

Unregistered
05-22-2010, 10:45 PM
Hi,

Sorry, for the Formula of %NaOCl the concentration of Na2S2O3 should be 0.1N as below:
Formula of %NaOCl = (V X 0.1N 0.003546) X 100 / weight of sample

Get back to your question: No, I didn't dilute after step 4. I titrated the 'mixture' straight after addition of all solutions (From step 1 to 4).
So, you suggest that after Step 4, the mixture has to be diluted. Can you please explain further why the 'mixture' need to be diluted? and the new formula for calculation.

Thank you very much.

Mrs X
05-24-2010, 10:41 AM
Hi,

Sorry, for the Formula of %NaOCl the concentration of Na2S2O3 should be 0.1N as below:
Formula of %NaOCl = (V X 0.1N 0.003546) X 100 / weight of sample

Get back to your question: No, I didn't dilute after step 4. I titrated the 'mixture' straight after addition of all solutions (From step 1 to 4).
So, you suggest that after Step 4, the mixture has to be diluted. Can you please explain further why the 'mixture' need to be diluted? and the new formula for calculation.

Thank you very much.
Hi, i need to look this reaction up at work. - I didn't have time yesterday sorry. Will try today. :)

Unregistered
05-25-2010, 06:19 AM
Hi,

Thank you.

Mrs X
05-26-2010, 01:32 AM
Hi, i'm so sorry, been very busy this week.

Dear Martin,

I have an enquiry. How do I calculate the ppm of chlorine in sodium hypochlorite,NaOCl if the percentage of the NaOCl is given, let say 3%?

Following is the method that I used to get the % NaOCl:
1. Weigh 1g of sample (Scrubber waste sample)
2. Add 25mL of Deionised water.
5. Titrate with Sodium Thiosulphate 0.1M until colourless.

Formula of %NaOCl = (V X 1.0N 0.003546) X 100 / weight of sample

Hi,

Sorry, for the Formula of %NaOCl the concentration of Na2S2O3 should be 0.1N as below:
Formula of %NaOCl = (V X 0.1N 0.003546) X 100 / weight of sample

Get back to your question: No, I didn't dilute after step 4. I titrated the 'mixture' straight after addition of all solutions (From step 1 to 4).
So, you suggest that after Step 4, the mixture has to be diluted. Can you please explain further why the 'mixture' need to be diluted? and the new formula for calculation.

Thank you very much.

This method is described in Vogel's Textbook of Quantitative Inorganic Analysis, and is much more simple than i was making it. :o

In your method, the hypochlorite is treated with an excess of potassium iodide and acidified with acetic acid:
OCl¯ + 2I¯ + 2H+ ↔ Cl¯ + I2 + H2O
The liberated iodine is titrated with standard sodium thiosulphate solution.

In your case the standard solution is 0.1N Na2S2O3.

The equivalents of thiosulphate used is equal to the equivalents of hypochlorite present.

Note: I think your 3% must be just the amount of Cl from the scrubber material not the total NaOCl, as you have used the molecular weight of Cl in your calculation. Another way to check this: The volume of 0.1N tiosulphate used to reach the endpoint in your titration must have been 8.5mL, which would be about right for a 20mL burette?

If you used 8.5mL thiosulphate, equivalents used = 8.5/1000 x 0.1 = 0.00085eq. You therefore have 0.00085eqOCl¯, or 0.00085 moles Cl in your 1g sample, as 1eq = 1mole for OCl.

Cl has a molar weight of 35.45g/mole.

Amount of Cl in sample is 0.00085 x 35.45 = 0.0301g. This is 0.0301/1 x 100% = 3.01% Cl

In a solid mixture, ppm would normally mean mg/kg, so your Cl is 30,100 ppm (w/w) in the scrubber mixture.

Good luck and again, sorry about being so slow to get back.

Unregistered
07-13-2011, 11:59 PM
I have got 25 ppm of chlorine solution out of this I need to make .2ppm by dissolving in water.How many litres of water should i use to get this concentraion by dissolving this 25 ppm solution.

Regards,

Uday

JohnS
07-14-2011, 01:38 AM
I have got 25 ppm of chlorine solution out of this I need to make .2ppm by dissolving in water.How many litres of water should i use to get this concentraion by dissolving this 25 ppm solution.

Regards,

Uday

The ratio of concentrations is 125:1. If you know how many liters of diluted solution you want, divide by 125, and measure out that amount of stock solution. 1 L of the diluted solution requires 8 mL of stock, dilute to 1 L total (uses about 992 mL of water).

Alternatively, measure out any convenient amount of stock, and dilute to a final volume of 125 times that.

Unregistered
10-09-2011, 09:26 PM
About 2 gallons. The method below is approximate as I don't know the density of your stock chlorine solution, but it is close enough.
13% is 130000 ppm, you want 50 ppm or, to dilute it 2600:1. You have 5000 gallons, 5000/2600 = 1.9 gallons, which I would just round to 2.

where did you get the value of 130000 ppm for the 13%?

JohnS
10-10-2011, 04:03 AM
where did you get the value of 130000 ppm for the 13%?

Its 13% of 1 million parts (the total)

tomkat
01-18-2012, 06:50 AM
What is the best way to calculate the amount of a liquid chemical (lets say chlorine) needed to raise the chlorine level in a given amount of water to reach a needed PPM? For example how many gallons of chlorine (at 13%) do I need to add to a body of water (5000 gallons) to raise the PPM to 50 PPM.
How much bleach @ 6% would it take to keep a range of 0.3ppm to 1.9ppm in 500 gallons of waste water per day?

Mrs X
01-19-2012, 01:29 PM
How much bleach @ 6% would it take to keep a range of 0.3ppm to 1.9ppm in 500 gallons of waste water per day?

The 0.3ppm - 1.9ppm presumably means mg available Cl2/L water? Cl2 gets used up - the rate will vary depending on biological loading and temperature, so you would have to work it out by trial and error and measuring it.

500US gallons is 1893L, so 1.9ppmCl2 is about 3600mg, or 3.6g.The bleach may be some sort of hypochlorite, so you have to work out what portion of your 6% is actually Cl. Sorry, not very helpful, but if you are treating waste water streams, i guess you have to do the measurements anyway. :)

Unregistered
02-22-2012, 12:45 AM
What is the accurate quantity in ml of chlorine to be dosed in 150L tank in the form of 3PPM

Unregistered
03-05-2012, 11:24 AM
Does an equation exist for converting ppm chlorine to a ph value?

Alexandra
04-02-2012, 01:24 AM
Hi Kevin, We have a 20,000 gal pool. Last year we had a problem with, what the girls at the pool store, lelcad martian poop. It was lime green at the deep end. They had us try all kinds of chemicals. We finally bought some phosphate remover that got rid of a lot of it. We struggled all summer with keeping the free chlorine up. Combined would jump up when I would try to shock. I had surgery and was just now able to uncover the pool. Here we go again. I have no free chlorine reading and my alk. stays high(170 to 200) it jumps around. When I try to shock, my combined jumps up, but no free chlorine. The pool store checked my well water and it checked high in phosphate. So, when I add water I am adding phosphate.Thanks, God Bless

Trin
07-10-2012, 04:14 PM
2ppm in 50m3 water how much chlorine do you add

Unregistered
09-27-2012, 12:15 PM
for a 50 gal wash machine i need a concentration of 2% chlorine how much chlorine would i need

JohnS
09-28-2012, 03:09 AM
for a 50 gal wash machine i need a concentration of 2% chlorine how much chlorine would i need

It is usually sold as liquid solution of sodium hypochlorite. You would need to know the concentration of your solution. Household bleach is usually sold at a concentration of 5-6%, and stronger solutions for pool use around 10-13%.

I would double check that you really want 2%. That is VERY strong, even for sanitizing equipment and hard surfaces; it would certainly damage or destroy fabric. But if you really want that, you would need 17 gallons of 6% bleach, or 5 gallons of 10% bleach, either diluted to 50 gallons. I would be very surprised if you really want more than 0.2%, which is a VERY strong sanitizing solution, and requires a water rinse (0.02% is the maximum allowed for sanitizing food processing equipment, even with a water rinse)

Unregistered
10-24-2012, 12:47 PM
How do you determine how many pounds of 65% chlorine is needed to bring chlorine level up to a particular level?

Unregistered
03-07-2013, 10:24 PM
How man of xy12 chlorine should should I pour in 1000 litres of water to get 50 ppm

JohnS
03-08-2013, 02:25 AM
How man of xy12 chlorine should should I pour in 1000 litres of water to get 50 ppm

Depend on whether the 12% is w/w or w/v; there are several ways to specify strength of chlorine solutions. Assuming w/v, it is 120 g/L or 120 000 ppm

1000 L x 50 ppm/120 000 ppm = 0.42 L

If the 12 % is w/w, then the strength will be a little higher on w/v basis (multiply by density), and the amount will be a little less.

Unregistered
05-27-2013, 12:30 PM
how much CL2 would be required to disinfect 350,000 gals of water, to a dosage of 5 PPM in gal or lbs. thanks

Unregistered
05-30-2013, 03:32 AM
What is the best way to calculate the amount of a liquid chemical (lets say chlorine) needed to raise the chlorine level in a given amount of water to reach a needed PPM? For example how many gallons of chlorine (at 13%) do I need to add to a body of water (5000 gallons) to raise the PPM to 50 PPM.

i want to chlorinate the water tank for our village so i want to know how much chlorine should i add to the water tank for it to reach the require ppm

helenam
09-06-2013, 06:13 AM
Add 1 drop of chlorine neutralizer for each "2 chlorine ppms".... what does this mean? how do i calculate it?? This is the instructions for my SPA testing kit. No explanations provided.

Mrs X
09-07-2013, 11:27 AM
Add 1 drop of chlorine neutralizer for each "2 chlorine ppms".... what does this mean? how do i calculate it?? This is the instructions for my SPA testing kit. No explanations provided.

Hi, would you be able to tell us what brand your test kit is? - we may be able to look it up. Also, do you know the volume of your spa pool? (Jacuzzi in American).

JohnS
09-08-2013, 05:30 AM
I am guessing the kit includes a container of known volume for the sample, and that "chlorine neutralizer" is some titrating solution. You add drop by drop, counting the drops, until a color change occurs, then double the number of drops for current chlorine level in ppm. (Drop sizes can vary, so no great precision should be expected)

To change the chlorine level in the pool. if it is not at the desired level, you would need to know volume of pool and strength of your chlorine solution.

Unregistered
02-28-2014, 09:36 PM
HELLO SIR

I NEED TO GET 2PPM OF CHLORINE IN 1000 Lit WATER .. CAN U TEL ME HOW MUCH AMOUNT OF CHLORINE TABLETS SHOULD BE ADDED TO GET 2PPM OF CHLORINE IN 1000 Lit WATER ..?

JohnS
03-01-2014, 04:34 AM
HELLO SIR

I NEED TO GET 2PPM OF CHLORINE IN 1000 Lit WATER .. CAN U TEL ME HOW MUCH AMOUNT OF CHLORINE TABLETS SHOULD BE ADDED TO GET 2PPM OF CHLORINE IN 1000 Lit WATER ..?

We need to know how much chlorine per tablet. You need 2 g of chlorine.

This is net. If the water is not perfectly clean (in which case it doesn't need chlorine), any "biological oxygen demand" will destroy some of the chlorine you add, giving a lower than expected result. It is usual to test levels after low level chlorination like this to see if you got what you expected.