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posted by chromas on Thursday September 23 2021, @09:50PM   Printer-friendly [Skip to comment(s)]
from the get-the-lead-out dept.

A new method for removing lead from drinking water: Engineers have designed a relatively low-cost, energy-efficient approach to treating water contaminated with heavy metals:

The new system is the latest in a series of applications based on initial findings six years ago by members of the same research team, initially developed for desalination of seawater or brackish water, and later adapted for removing radioactive compounds from the cooling water of nuclear power plants. The new version is the first such method that might be applicable for treating household water supplies, as well as industrial uses.

[...] The biggest challenge in trying to remove lead is that it is generally present in such tiny concentrations, vastly exceeded by other elements or compounds. For example, sodium is typically present in drinking water at a concentration of tens of parts per million, whereas lead can be highly toxic at just a few parts per billion. Most existing processes, such as reverse osmosis or distillation, remove everything at once, Alkhadra explains. This not only takes much more energy than would be needed for a selective removal, but it's counterproductive since small amounts of elements such as sodium and magnesium are actually essential for healthy drinking water.

The new approach uses a process called shock electrodialysis, in which an electric field is used to produce a shockwave inside an electrically charged porous material carrying the contaminated water. The shock wave propagates from one side to the other as the voltage increases, leaving behind a zone where the metal ions are depleted, and separating the feed stream into a brine and a fresh stream. The process results in a 95 percent reduction of lead from the outgoing fresh stream.

[...] The process still has its limitations, as it has only been demonstrated at small laboratory scale and at quite slow flow rates. Scaling up the process to make it practical for in-home use will require further research, and larger-scale industrial uses will take even longer.

Journal Reference:
Huanhuan Tian, Mohammad A. Alkhadra, Kameron M. Conforti, et al. Continuous and Selective Removal of Lead from Drinking Water by Shock Electrodialysis, ACS ES&T Water (DOI: 10.1021/acsestwater.1c00234)


Original Submission

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Heavy metals contaminate ground and surface waters from a variety of sources such as industrial effluent or fertilizers or pesticide applications. Cadmium and lead are the most common and toxic metals found in aqueous environments. They are persistent, they migrate, they accumulate in biological tissues, and they are carcinogenic. Removing these metals effectively and cheaply has been a big environmental challenge. There are a number of approaches to remove them including reverse osmosis, ion-exchange, chemical precipitation, coagulation, electrochemical treatment, and physical adsorption. Of these, adsorption is seen as very promising due to it being cost-effective, widely available, and easy to implement. There are a wide variety of adsorbent materials from the mundane (activated carbon, diatomaceous earth, polymers, etc.) to the exotic (carbon nanotubes and graphene oxide), but biochar has shown to be very efficient and cost-effective.

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  • (Score: -1, Flamebait) by Anonymous Coward on Thursday September 23 2021, @10:14PM (1 child)

    by Anonymous Coward on Thursday September 23 2021, @10:14PM (#1180894)

    Filter it through African Americans.

    • (Score: -1, Flamebait) by Anonymous Coward on Friday September 24 2021, @12:57AM

      by Anonymous Coward on Friday September 24 2021, @12:57AM (#1180949)

      And then what, we all get to drink nigger piss? No thanks.

  • (Score: 2) by hendrikboom on Thursday September 23 2021, @10:28PM (3 children)

    by hendrikboom (1125) Subscriber Badge on Thursday September 23 2021, @10:28PM (#1180899) Homepage Journal

    Let's hope it doesn't remove the fluorides we need for teeth.

    • (Score: 0) by Anonymous Coward on Thursday September 23 2021, @10:32PM

      by Anonymous Coward on Thursday September 23 2021, @10:32PM (#1180901)

      I thought the fluoride was for mind control? Citation: https://rense.com/general79/hd3.htm [rense.com]

    • (Score: 3, Interesting) by Splodgy Emoji on Friday September 24 2021, @10:03AM (1 child)

      by Splodgy Emoji (15109) on Friday September 24 2021, @10:03AM (#1181075)

      1. If you brush your teeth regularly with a typical 1450ppm fluoride toothpaste, that concentration is 1450 times higher than the typical 1ppm fluoride in drinking water.

      2. If you drink a moutful of fluoridated drinking water, it goes into your mouth and disappears down your throat when you swallow it. After a few minutes, almost none of the mouthful of water remains in your mouth. After several hours, none of the fluoride in the drinking water can be detected in saliva in the mouth.

      3. Fluoride toothpaste is a gel-like so and it is directly applied to the teeth and is forced into holes and crevices of the teeth by the brushing action. The fluoride does not completely wash off during rinsing your mouth after brushing. Fluoride from toothpaste can be detected in the mouth, even several hours after brushing and rinsing.

        → Ingestion and absorption of fluoride from 1450ppm fluoride in toothpaste are greater than from 1ppm fluoride in drinking water,

        → Fluoride from toothpaste is delivered and remains where it matters most - onto the teeth, not into other parts of the body.

        → Production, transport, and application of fluorosilicic acid for drinking water fluoridation is not environmentally friendly and is not sustainable.

        |→ 𝓠.𝓔.𝓓.

      • (Score: 0) by Anonymous Coward on Friday September 24 2021, @03:13PM

        by Anonymous Coward on Friday September 24 2021, @03:13PM (#1181128)

        It goes directly to your brain, that's why you can't detect it. Tin foil can't protect you once it's INSIDE YOUR BRAIN!!1

  • (Score: 0) by Anonymous Coward on Friday September 24 2021, @12:33AM

    by Anonymous Coward on Friday September 24 2021, @12:33AM (#1180942)

    Like the 737-MAX you just need to rebrand it as something like electrolytes and the kids will be all over it. Trust me.

  • (Score: 0) by Anonymous Coward on Friday September 24 2021, @01:31AM (2 children)

    by Anonymous Coward on Friday September 24 2021, @01:31AM (#1180960)

    That's not very useful. To what concentrations can it bring the lead down to, in ppb, and at what cost compared to existing methods.

    Also you typically run water through much cheaper coarses filters before running it through the much more expensive fine filters. There is also deionization processes you can run after filtration.

    • (Score: -1, Offtopic) by Anonymous Coward on Friday September 24 2021, @01:33AM

      by Anonymous Coward on Friday September 24 2021, @01:33AM (#1180961)

      Coarse filters, stupid auto complete.*

    • (Score: 0) by Anonymous Coward on Friday September 24 2021, @04:34PM

      by Anonymous Coward on Friday September 24 2021, @04:34PM (#1181157)

      Also what would be more useful would be something cheap and portable that can measure lead in PPB.

      You have those PPM meters and you can get that zero water that can reduce detectable ions down to 0 PPM but if lead can be harmful in parts per billion then a PPM meter isn't that useful in telling me if my water is really safe and if my filter is removing all the undesirable contaminants to safe concentrations or if it's not working and needs to be changed or replaced or I need to find a different filter or another source of water or whatnot.

      I need to start with the ability to detect/measure undesirable contaminants before I can determine if they are present and need to be removed and if they have been sufficiently removed by whatever process you are selling me.

  • (Score: 0) by Anonymous Coward on Friday September 24 2021, @02:10AM (4 children)

    by Anonymous Coward on Friday September 24 2021, @02:10AM (#1180972)

    So is it cheaper than my Brita filter [brita.com], which you will need to pry from my cold dead hands ( - or better still, buy your own).

    • (Score: -1, Troll) by Anonymous Coward on Friday September 24 2021, @02:47AM (1 child)

      by Anonymous Coward on Friday September 24 2021, @02:47AM (#1180982)

      I use magnets and Gwynyth Paltrow energy crystals to purify my chakras.

      • (Score: 0) by Anonymous Coward on Friday September 24 2021, @03:16PM

        by Anonymous Coward on Friday September 24 2021, @03:16PM (#1181131)

        It doesn't remove the lead but makes everything smell like vagina. I love the smell of vagina in the morning.

    • (Score: 0) by Anonymous Coward on Friday September 24 2021, @06:09AM

      by Anonymous Coward on Friday September 24 2021, @06:09AM (#1181033)

      If the Brita doesn't filter out all that lead then you might get your wish

    • (Score: 2) by DeathMonkey on Friday September 24 2021, @03:37PM

      by DeathMonkey (1380) on Friday September 24 2021, @03:37PM (#1181143) Journal

      So is it cheaper than my Brita filter [brita.com], which you will need to pry from my cold dead hands ( - or better still, buy your own).

      This process removes dissolved lead. Your Brita filter can only remove lead particulate.

      If this ever gets deployed commercially there would likely be a brita-type filter pre-treatment to get all the particulate out then use the electrodialysis to get the dissolved stuff.

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