Question: How does distillation remove chemicals such as chlorine? Won't chlorine and other harmful chemicals simply vaporize with the water vapor? How then does the distiller separate the chlorine vapor from the water vapor?

Thank you for your excellent question. As a starting point, I want to clarify that we use distillation as our core treatment technology because it consistently removes the largest range of contaminants, but we also incorporate other treatment methods into our water distillers. There is no treatment process that is perfect, distillation included. 

A good rule of thumb is that distillation is extremely effective in removing contaminants that have a higher boiling point than water, which is the vast majority of contaminants. There are some inorganic and organic chemicals that have a lower boiling point than water, such as chlorine. We handle this in two ways… 

First, our distillers incorporate twin volatile gas vents, a patented feature. These are two small holes that allow gases that are lighter than air, such as chlorine to harmlessly vent out.   

Second, all of our water distillers incorporate carbon filters, which are very effective at removing these gases that still happen to be present. Since we are running distilled water through the carbon filters we can make these filters last a very long time and we avoid the normal problems of carbon filters which include bacterial contamination.

We have tested the effectiveness of our machines on chlorine with and without a carbon filter. Without a carbon filter we achieved a 93% to 95% removal rate of chlorine. With the carbon filter we achieved a 99% plus (which means that no chlorine was detected).

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31 Responses to “Question: How does distillation remove chemicals such as chlorine? Won't chlorine and other harmful chemicals simply vaporize with the water vapor? How then does the distiller separate the chlorine vapor from the water vapor?”

  1. Bob March 5, 2013 at 11:26 pm #

    1) Please elaborate on the carbon filter that is used in conjunction with the distiller. Carbon Filters are notorious for breeding bacteria and viruses. How is it that your filter does not have this issue? Even if it is distilled water, the carbon filter will be moist. Bacteria love moisture. What mechanism inhibits their growth?

    2) Does your carbon filter ever need to be replaced? If so, how often? Once a year?

    3) I am seeing mixed information about distillation’s capability of removing fluoride. I have seen citations indicating that distillation can only remove about 60% of fluoride…the rest stays. To complicate things further, there are different compounds by which fluoride is administered, namely:

    – Sodium fluoride (NaF)

    – Fluorosilicic acid (H2SiF6)

    – Sodium fluorosilicate (Na2SiF6)

    Their boiling points must all be different. What is distillation’s effectiveness against all three?

    I have more questions, but this is good enough for now : )

    • Pure Water March 6, 2013 at 5:47 pm #

      First, a bacteria needs 3 things to survive. food, moisture, darkness. Our Filter which is the last step of the distillation process denies them food, because the distilled water at this point is devoid of anything for a bacteria to feed on. Also because distillation involves boiling the water to vaporization, bacteria and viruses are killed by the heat. Since viruses and bacteria are heavier than air (there are airborne bacteria but most are not dangerous and we breath in every day) they remain behind in the boiling chamber and are not carried to the filter.
      For the second question I will first let you know that we have third party laboratory tests that give 99.9% reduction of fluoride. As for the three you mentioned, Sodium fluoride and Sodium fluorosilicate have too high of a boiling point 1695 C and 500 C respectively. Fluorosilicic acid boils at 212F which is the same as water but because of VOC vents we remove 95-99.9% of the fluoride there and the post carbon filter should be removing anything that may have got through that process. I hope this answers your questions and let us know if there is anything else we can answer for you.

      • carmine December 4, 2015 at 2:22 am #

        Have you tested for fluoride with and without the carbon filter? If so, what was the results/difference? Thanks.

        • jimblakley December 9, 2015 at 4:35 pm #

          A carbon filter does virtually nothing to remove fluoride so with or without the filter, the removal should be the same. For this reason we have not done any tests specifically for this.

          • carmine December 15, 2015 at 9:57 am #

            Okay thanks a lot. And do you work for Pure Water?

            So for the test that was done, was the water tested filtered using the carbon or not? Thanks again.

          • jimblakley December 29, 2015 at 7:28 pm #

            It was tested using the carbon filter.

  2. lora durak March 25, 2013 at 2:14 pm #

    I realize that you have VOC vents on your distiller, but have you tested for HAA’s (Haloacetic acids), THM’s (Thihalomethanes) and DBP’s (Disinfectin Byproducts such as Chloramines, Chlorine Dioxide, Chloroform) from the third party laboratory? If so, would you be willing to post those results online?
    Also, is there any nickel used in the metal of the distiller? Have you tested for nickel in the final water prduct? Finally, have you had an independent 3rd party test done on the many other VOC’s in the final water product? If so, what laboratory did you use?

    I guess I also need to know if you are starting off with well water or water that has gone through the municipal system… because this does matter!

    I want to be able to potentially refer my clients to you, but need to know some more information. I do realize that there is no perfect system out there. 🙂

    Thanks so much,
    Lora Durak

    • Ally July 20, 2014 at 1:10 am #

      Im also interested to hear the answer to Lora’s questions -can anyone from your company respond to this questions ….:) just think that the question was posted today!

      Thanks in advance.

    • MyPureWater January 16, 2015 at 2:56 pm #

      https://mypurewater.com/wp-content/uploads/2015/01/Lab-Test-Results-Extended.pdf

      Thanks for the question Lora. I have added a link above to a list of what contaminants we had tested for removal rates. Hopefully that will give you a better understanding of what we have looked at for removal. The water is actually contaminated before hand and then tested on removal to get a more exact number. We have actually run a test on just allowing distilled water to sit in our storage tanks and then testing the water after 4 months. After 4 months we tested the water and there was no measurable nickel in it. Hopefully that answers your questions.

  3. candace colling July 31, 2013 at 6:02 pm #

    Hi, I’m buying a home close to a former nickel plant. I’m worried about nickel dust, arsenic, cobalt and lead which have all been found in the soil around the plant which operated from 1918-1985. I will be drinking the well water, would your system work or should I look at building a cistern and having water delivered?
    Thanks for your help.
    Candace

    • jimblakley August 21, 2013 at 9:44 am #

      Thanks for the question Candace, Our distillers have a 99.9+% removal rate of nickel, arsenic, cobalt and lead. Distillation is going to be the #1 way to remove these contaminants from your water consistently without a drop off in purity.

  4. Ron Mink September 29, 2013 at 9:22 pm #

    I am wondering if the chlorine and other toxic gases being vented are harmful to breathe. If I operate your distiller in my living space am I not going to poison myself and my family?
    Thanks for the helpful Q&A space!
    Ron

    • MyPureWater September 30, 2013 at 8:53 am #

      That is a great question Ron, The first thing to remember though is that as these are volatile gases, any time you run hot water from the tap, run a dishwasher, or take a hot shower, you are venting these gases into the air. Much more than would be released by a distiller. The second thing to remember is that they are volatile and since they are lighter than air, they will vent out and disperse quickly. If you are worried about it, you are going to want to run a carbon pre-filter. If you are just worried about it from an automatic distiller, you can add a pre-filter onto the line. If you have a counter top model, you would need to get a whole house carbon filter. Carbon filters are good at removing most Volatile Organic Compounds. If you are interested in one of these, you can contact our sales dept. for more information.

      • Linda S. August 26, 2016 at 2:39 pm #

        Thank you for asking the question that I was wondering about also, Ron. I’m sorry, I don’t understand the answer. I heard Brian Clement mention that his distiller is in his garage which makes sense, but I live in a small apartment and don’t have that option. Why does a shower release more VOCs than a distiller, because there’s more water being heated? You say VOCs are lighter than air and will disperse quickly. I assume they’ll disperse up to the room’s ceiling? Would opening a window help at all? My apartment doesn’t even have an exhaust fan. Is there a diagram somewhere that will explain the distillation process and what is removed when? Is there contaminated water that is left and needs to be, I guess, put down the drain?

        • jimblakley August 29, 2016 at 9:48 pm #

          Any time water is heated, it releases VOCs. This occurs because they vaporize at a lower temp than the water does. A shower will produce more VOC’s because more water is being heated. They are lighter than air and disperse quickly. Your home is not air tight. They will vent to the outside quick.
          Check here, https://mypurewater.com/home-products/distillers-for-homes/#chapter6, for a good drawing on how distillation works. all of our distillers will leave water left over in the boiling tank which will contain all the contaminants that couldn’t vaporize with the water. These will need to be drained out on a regular basis.

          • Linda S. September 2, 2016 at 5:19 pm #

            Thank you, Jim.

  5. Babban May 7, 2015 at 8:50 pm #

    I do not see in the contaminants removal list one chemical: Chloramine
    Is Chloramine removed by your distiller?

    Babban

    • jimblakley May 11, 2015 at 8:07 pm #

      Hello Babban,
      Chloramines are actually a large group of different ammonia and chloride ions. Looking on the sheet we have a number of dichloro- compounds and trichloro compounds. All with >99.9% removal. I also have this response from Eldon Muehling, our Dr. Water.

      Ask Dr. Water: Surface Water and Distillation
      By Eldon Muehling
      Question:
      Are Pure Water Distillers recommended for surface water systems with high organic content, high chlorine and/or chloramines disinfection?

      Answer from Dr. Water:
      Yes they are. All of our household distillation systems have twin volatile gas vents and an activated carbon filter as post-treatment after the water has been distilled. The purpose for these features is to rid the distilled water of volatile contaminants, both organic (such as Chloramines, certain solvents, pesticides, etc.) and inorganic (such as Chlorine, Hydrogen Sulfide, Ammonia, etc.).

      The twin volatile gas vents are a patented design feature not found on any other distillers. This is why Pure Water distillers do a better job than other distillers in the removal of such contaminants. This has been confirmed by independent 3rd party E.P.A. certified laboratories.

      I hope that answers your question.

  6. Loanemu May 11, 2015 at 6:20 am #

    I cannot thank you enough for the blog article.Much thanks again. Much obliged.

  7. Andrew October 1, 2015 at 6:09 am #

    Could you clarify for me how distillers with vebts for volatile gases differentiate the volatile gas from the water vapor? If these vents do suck the gas out (some have fans that blow them out of the distiller) then why aren’t they venting the water vapor too?

    • jimblakley October 1, 2015 at 3:10 pm #

      The vents are strategically positioned on the cooling coil where the steam is cooled down as is no longer lighter than air. Essentially at this point, the steam is too heavy to vent out of the condensing coil. VOCs are lighter and will rise up out of the vents at this point. This process combined with a post VOC filter will give you greater than 99% VOC removal.

      • Andrew October 2, 2015 at 5:34 am #

        So why does the cooling coil cool the water vapor but not the VOCs?

  8. Cheryl October 1, 2015 at 2:01 pm #

    We have found chlorine in our distilled water. Wondering how that may be in there after going through the distillation process. How often should the carbon filter be changed?

    • jimblakley October 1, 2015 at 2:45 pm #

      Since chlorine has a lower boiling point than water, when boiled it will turn into a gaseous compound, commonly known as a VOC (Volatile Organic Compound). This means that instead of remaining behind in your boiling tank like most other contaminants, it will rise up with your steam. We incorporate a dual volatile venting system on the cooling coil, strategically placed to remove the majority of VOCs and then post VOC filter is there as a final step of purification. If your filter is old though and the carbon is no longer absorbing gases, you may get some chlorine in your final distilled water. We recommend these filters be changed every 3 and 6 months, depending on the type of distiller you have. If you let us know which model you have, I’d be happy to follow up with you on the proper maintenance schedule.

  9. Cheryl October 6, 2015 at 5:44 pm #

    Thank you so much for your response. It looks like the one we have is a polar bear Model is either PK-4 or PK-4/PO. If you have a recommendation for a maintenance schedule that would be great. The gentlemen that took care of it for us retired many years ago and there has no really been anyone to maintain it. Thanks again for your help.

    Best, Cheryl

  10. rob September 21, 2016 at 8:13 am #

    Hi – In the alcohol distilling industry they remove the “tops” and the “tails” of the distilled mixture. The tops being the first couple of percent of the distilled mixture and the tails being the last few percent. This is because the volatile oils and contaminants that boil below the boiling point of water will vent off first (the tops) – and the contaminants that have a higher boiling point will boil off last (the tails) my question is –
    Would you advise the home water distiller to dicard the “tops” and the “tails” of the distilled water to ensure a purer end result?
    Have you done any tests in the “tops” and the “tails” of your distiller to see if there is any difference?

    • jimblakley September 21, 2016 at 2:20 pm #

      The removal of the tops and tails is already worked into our design. The “tops” or anything with a lower boiling point than the water will rise up with your steam. We have patented dual vents on the cooling coil that vent most of these off and then use a post carbon filter which should give us over 99.9% removal of most VOCs. As for the “tails”. Our heating elements are submerged in the boiling tank which means they are surrounded by water. As long as they are covered by water, they cannot increase the temperature above the boiling point of water. So we have designed our distillers to not boil dry. they will always shut off with water covering the element. This way no “tails” have a chance to vaporize. Thank you for your great question.

  11. Derek September 25, 2016 at 2:57 am #

    Hi, I’m interested in a counter top unit. Do all your distillers, ie, the Pure Mini Classic, the AquaNui Countertop unit, and the Steam Pure countertop unit, incorporate the dual VOC vents? Is there a verification of this in the manuals? Thanks!

    • jimblakley September 26, 2016 at 3:01 pm #

      Yes Derek, all of our current residential model distillers use the patented dual vents on the cooling coil for VOC removal. Each manual should make mention of it. If there is anything else you need, feel free to give us a call at (800) 875-5915 ext. 3 for more information.

  12. Dolores January 16, 2017 at 3:33 am #

    I have been using a water distiller for 30 years. I have only paid 100 dollars or less. I didn’t know there were machines that cost 5 or 600 . Why is your so expensive if it does the same thing. By the way, the cleaning solution is not necessary, as white vinegar does a beautiful job and the tank is sparkling. If I am missing something, please, I would appreciate the information.

    • jimblakley January 27, 2017 at 4:28 pm #

      Hello Dolores and thank you for your comment. If you have used a distiller for 30 years and only paid $100 for it, that is impressive. Though this is not the common story we hear. As far as we know, we are the only company making a counter top distiller in the U.S. which means they all come from places like China. We get complaints that they barely lasted a few months, don’t use stainless steel or that the water is touching plastic. Customers come to us because we have distillers that are made with U.S. Stainless steel throughout, come with the longest warranty you can find and last well into 30+ years. We are the more expensive model, but we make sure you don’t need to keep replacing the distiller every year.
      You are correct, you don’t need Lumen. We do recommend using either Lumen or a 50/50 solution of warm water and white distilled vinegar. The difference in their effectiveness is based on what type of scale contamination you have. Some scale is removed better by Vinegar and others by Lumen. It all depends on what type of mineral concentration you have in your tap water in your area. If you have any other questions, we would be happy to hear from you. You can reach us at (800) 875-5915 ext. 3. Thank you once again for your comment.

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