Low cost solution to remove both pathogen and chemicals including lead from drinking water at household level?

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Hi everyone, I am part of Hope for Children team implementing Water & Sanitation project in Namuwongo slum (Kampala City, Uganda).
The slum gets water from National Water & Sewerage Corporation (NWSC) which is inadequate. 
Over 60% of population directly reies on groundwater-based water source like wells. However, water quality tests indicate that the groundwater is contaminated by faecal and heavy metal (lead) contaminants. Lead concentration range from 0.1 - 0.2 mg/l whereas 0.05 mg/l is the maximum permissible value. 
Therefore to get safe drinking water, we intended to introduce and promote household level drinking water treatment methods. Regardless of the water source, it must become safe before drinking (both chemically and biologically).

I have looked at some discussions on The Water Network about this topic, they are great, but most of the solutions are limited to disinfection against pathogens.

Can anyone suggest some water treatment methods at household level capable of chemical and microbial removal?

Best regards

Draleke Titus

 

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24 Answers

  1. The Water Network research team has consolidated an answer to the above question. 
    Further input from members is welcome and appreciated.

     

    Lead in water often comes from corrosion of pipes which happens mostly due to an acidic environment.

    It is recommended to adjust the pH levels at point of use (POU). When the pH is increased the water will be less corrosive and this may be sufficient for lead levels to return to acceptable limits and this may eliminate the need for any further treatment.

    As a cheap solution for pH adjustments, we suggest Magnesium oxide beads.
    Read about other pH adjustment methods here .

    Lead has a high affinity towards resin since it has high molecular weight and a valence of 2+.
    Lead will come in place of the most charged metal ions in the resin and will not strip from it easily even when the salts or strong acids added.

    If water pH is above 7, lead may be precipitated in a non-ionic colloidal form which cannot be removed by ion exchange and must be physically filtered.
     

    EPA has set a primary drinking standard for lead of 0.015 ppm. 

     

    Magnesium oxide beads

    Prill MgO beads are used when the water pH needs to be rasied.

    They should be used after reverse osmosis.

    Osmosis is a spontaneous movement of the molecules in the solvent through a semi- permeable membrane. The molecules tend to “ go” to the in that direction that will equalize the concentrations of the two sides. Reverse osmosis is a process in which the particles move in the opposite direction than in natural osmosis. The contaminated fluid passes through the membrane and the suspended particles are separated from the liquid. For this process, pressure is needed – the hydrostatic pressure needs to be greater than the osmotic pressure.

    Prilly Pure Water  Beads raise and balance pH levels of the water to 8,7 without any chemicals.

    The beads are made from magnesium oxide which is produced from naturally occurring salts of magnesium found in rich brine deposits located approximately 2, 500 feet below ground. The resulting magnesium oxide is ‘ prilled’ into small, hard pellets by a high temperature firing process which turns them into small ceramic-like pellets.

    In addition to adjusting the pH, the beads lower the surface tension of water, remove toxins and pull out heavy metals from water.

    Prilly Pure Water  Beads last forever and never need to be replaced.

     

    1.jpgIon exchange

    Ion exchange is a physical- chemical process in which  ions are swapped between a solution phase and solid resin phase.

    Ion exchange resins are ion exchange polymers that are insoluble. They form small beads that are porous (water can pass through them). That way they provide a large surface area.  

    The process is named due to some ions being trapped and others released.

    Ion exchange is also used for water softening.

    Ion-exchange resins are used to replace the  magnesium  and  calcium ions in hard water  with  sodium  ions.

    Fresh resin contains sodium ions at its active sites. When in contact with a solution containing magnesium and calcium ions (but a low concentration of sodium ions), the magnesium and calcium ions preferentially migrate out of solution to the active sites on the resin, being replaced in solution by sodium ions.
    This process reaches equilibrium with a much lower concentration of magnesium and calcium ions in solution than was started with.

     

    These methods should be combined with some of the following methods for bacteria and viruses removal include:

     

    Chlorine

    One of the most reliable treatments is Chlorine. It kills microbes and prevents new contamination long after it is added.

    Chlorine is a highly efficient disinfectant.

    Chlorine is a gas at atmospheric pressure but turns liquid under pressure. It is transformed and applied as a liquid.

    It is a strong oxidizing agent and has disinfectant abilities due to oxidation of organic molecules.

     

    2.jpgMoringa Oleifera

    The Moringa Oleifera tree grows in tropical and subtropical regions.

    It needs six months to reach fruition and is used in many areas as a food source. The seedpods, seeds, leaves, roots and flowers are all edible and nutritious.

    Moringa Oleifera trees are widely present in Africa, the Middle East and the Indian subcontinent.

    It is a fast growing (4.6 meters/year) crop tree that does well in the equator belt climates with non-soggy soils. 

    The tree's seed grow in pods. Dried, hulled, and ground seeds have a significant ability to reduce the suspended solids in extremely turbid waters.

    Dried beans and seeds can be stored for a long time. 

    The shelled seeds provide much higher turbidity removal than the non-shelled ones.

    Moringa Oleifera is a coagulant and an antimicrobial agent.

    When adsorbed onto sand, a protein in dried and ground seeds, has excellent results in removing total suspended solids (TSS) and killing coliform bacteria. 

    A positively- charged protein called the Moringa Oleifera Cationic Protein (MOCP) is responsible for the excellent water- clarifying ability of the seeds.

    When the seeds are crushed and added to water, this protein will kill the microbial organisms and cause them to clump together and settle at the bottom.

    Moringa Oleifera seeds also have the ability to reduce E. Coli.

    * A dominant mechanism of MOCP antimicrobial activity is membrane fusion. Cryogenic electron experiments on E. coli cells established that MOCP fuses the inner and outer membranes.
     

    Bacteria and viruses can attach themselves to the suspended particles in water and cause turbidity. Therefore, reducing turbidity levels through coagulation may improve the microbiological quality of water.

    The dried seed powder alone is not ideal for water purification because the organic matter from the seed will remain in the water, providing a food source for any bacteria that have not been killed. As a result, water treated with this seed does not remain safe to drink after some time in storage.

    Water clarified with Moringa seeds must be used immediately.

     

    Carbon filtration

    3.png
    Diagram: Activated carbon filtration
    Source: en. wikipedia.org/ wiki/Carbon_ filtering#/ media/File: Water_ Filtration_ Systems.png

    Carbon filtering  is a method that uses a bed of  activated carbon to remove contaminants and impurities, using chemical  adsorption ( adhesion of atoms, ions, or molecules from a fluid or dissolved solid to a surface).

    Activated carbon traps pollutant molecules inside the pore structure of the carbon substrate. 

    Each particle/ granule of carbon provides a large surface area/pore structure, allowing contaminants the maximum possible exposure to the active sites within the filter media.
    (One pound of activated carbon contains a surface area of approximately 100 acres.)  

    Because of its molecular makeup, activated carbon can adsorb well, meaning that it can take in or collect many organic molecules on its surface.

    Granular activated carbon filters are inexpensive and maintenance involves replacing six to twelve cartridges a year, depending on the quality of the raw water and the filter media.

    Active charcoal carbon filters are most effective at removing  chlorine,  sediment,  volatile organic compounds, taste and  odor from water. They are not effective at removing  minerals,  salts, and dissolved inorganic compounds.

     

    Solar sterilization and solar distilation

    If it is important the method is cheap, and time is not a concern, leaving the water in a plastic bottle in sunlight might be a good solution.

    Clear bottles should left in the sunlight for the UV radiation and heat to kill the microbes.

    The time of exposure to the sunlight depends on the availability – sterilization takes longer on cloudy days.
     

    Solar distillation purifies even muddy, salty and undrinkable water using evaporation and condensation.

    The sun shines on the impure water, which gets heated and evaporates then condenses and runs into a container.

  2. SIMPLY INSTALL FILTER AND CARBON CARTRIDGES WITH UV SYSTEM TO SOLVE THE PROBLEM

     

  3. Good day Titus

    We have a solution that will be able to assist you in your search. Our units is not only cost effective but we have different water sterilisation units. All our units has been tested through SANAS Water lab. We do not use any chemicals nor RO and have only about 4% water loss on the drinkable water through our system. My direct email address is adriaan.winterbach@solcentury.co.za and feel free to visit our website www.solcentury.co.za.

    Regards

    Ariaan

  4. Hi,

    If you could contact me directly on email doug@solarienergy.com.au please. We have developed solutions to treat sewerage water to be safe for contact such as use in parks and gardens, and then furhter treatment through to drinking water. We use the Australian Standards for this as our guide which are very strict and always being checked. We can contimue this discussion through the email

    Regards

    Doug


  5. The magnesium oxide (MgO) used in the Prilly Pure Water bags actual places a positive charge in the water. This electromagnetic charge shatters the magnetic bond that holds together any Totally Dissolved Solids (TDS), and heavy metals like chlorine, fluoride, lead, copper and also the Emerging Contaminants such as pesticides and pharmaceuticals. These contaminants and pollutants are then gassed out of the container. This is a living water. The pH of the water is raised to 8.7, high alkaline, high oxygen and the water is structured "thin" so as to more readily penetrate the cell membrane and to deliver oxygen, nutrients and pure water and flush out your toxins. As to hydration, due to it being "thinner" water, 3 glasses of Prilly Pure Water is equal to 1 gallon of tap water. The MgO has been processed at 700 degrees Fahrenheit and made to be more ceramic like a marble in water that never dissolves, never wears out and never needs to be replaced. No expensive equipment, No costly replacement filters, No electricity, and No more bottled water. This a 1 time investment of only $40 for Water Freedom, and the Final Barrier between Invisible Bad Water and YOUR lips.

  6. Have you considered Rainwater harvesting?

    If you could construct a storage tank for the rain water to run in to. Then the water you start with would not contain lead. Plus with a simple percolation filter where the water from the tank flows through a sand bed into barrels ready to transport.

    The sand filter could be make using two barrels half filling a barrel with sand and drilling a very small pin hole in the bottom to allow th ewater to drip out into another barrel. . .

    Another way I can suggest is evaporation type system. Using the heat of the sun to make vapor and then collecting the vapor on a condensing surface. I would find an area with a gentle slope in the sun light. lay a sheet of plastic on the ground with another 50cm above making sure they dont touch. Then collect the droplet as they role down the above sheet.

    I am an inventor so these are just ideas and not tried and test industry solutions. But if you want me to explain in more detail let me know.

  7. Water & Sanitation project in Namuwongo slum

    Greetings Mr. Titus

    I hope you are well.  Thank you for sharing your story above regarding your work in the Namuwongo Slums.  I would like to connect with you directly via e-mail to learn more regarding your work there as well as Hope for Children.  I have sent you a LinkedIn invite as well.

    Please feel free to e-mail me directly at jtechau@tricorllc.com

    All the best to you.

    Jason Techau

    Skype:  jason.techau (Lee's Summit MO)

     

  9. Moringa Olifera and other natural seeds

    Dear Titus,

    I have looked through the responses below and noted a number of people have offered potential solutions.

    One option which is effective against both microbial contaminants and lead is the P&G Purifier of Water. This product is available in Uganda and is sold in small packets suitable for application at the household level. If you are focused on vulnerable groups with limited disposable income, and particularly people living with HIV, you may wish to look at working with local groups providing them with anti-retroviral medication, and basic foodstuffs for nutritional well-being. The benefit of the P&G Purifier of Water is that it is effective against cryptosporidium, which is particularly nefarious in people living with HIV, and which is resistant to chlorine.

    A low-cost option which you may want to look at for lead removal is the use of moringa olifera. I am not familiar with the range of evidence supporting this option but here is a link to an article which suggests that moringa olifera was effective at reducing lead contamination in household drinking-water.

    http://blogs.washplus.org/drinkingwaterupdates/2012/06/water-purification-using-moringa-oleifera-and-other-locally-available-seeds-in-fiji-for-heavy-metal-removal/

    Are you familiar with the International Network on Household Water Treatment and Safe Storage, which is led by WHO and UNICEF and has over 150 member organizations worldwide? It is another forum for circulating such questions and linking to good sources of knowledge on household water treatment. If you would like more information, please provide me your email address and I will add you to the mailing list.

    Best regards
    Ryan

  10. How about a simple 2 stage RO system (with activated carbon filter), they are commercially available as a package system. Various sizes are available at household levels. This is if electricity is available. But if you planning to do research then we can speak more. If you can give the details of the water quality. In the past we developed a hand driven membrane system for emergency situation. But I am not sure heavy metal can be removed by such system. As its a UF based system. I think this problem seems to be interesting. Hopefully you can share more info.

  11. Microfiltration with adsorptive resins

    Mixed bed resins followed by low cost ceramic filter is a good solution. We are having many systems in India even for Arsenic, can share details if we have more flow data and full water characterisation

  13. Good Day this is Dr Abe Beagles from Cal-Neva Water Quality Research Institute in California. Back in 2003 we developed a technology that was meant for the frac water that was coming back from the Barnett Shale Natural Gas wells in Texas. It is called Electro-coagulation and it will remove 99.7% of all heavy metals and it will kill any virus, bacteria, ecoli or eboli in the water. It will only need to be filtered after passing theough the system to remove the sediment from the heavy metal removal. If you go to www.eco-web.com and go to the Authors Tab you will find my white papers on this technology in the 5th to the 9th slots under Authors. If one of these systems were put on every well you would have no problem. We have two 100 GPM units built and ready to ship at the present time and they can be purchased at a resanoble price. My email is gerrybeagles@aol.com and my phone here in Sierra Leone is 232 078 402 353 which is where I am at this time. My Skype is "abescousin1" so if you want to find out more about how to solve your problem give me a call.

  14. Toutes les bactéries sont des bactéries utiles et aucune parmi toutes est pathogène. Toutes les bactéries ont un rôle à jouer dans le développement et la gestion de la vie sur terre. Certaines bactéries sont là pour l'élimination des mayons faibles, la séléction naturelle de la vie. D'autres sont là pour participer à la destructuration de la matière pour lui permettre d'être recyclée, aucune n'est pathogène. Certaines vivent dans des milieux agressifs et doivent s'adapter à leur milieu. Concernant les matériuax lourds le sol en a besoin, l'homme en rejette et ce n'est donc pas un problème plus que cela. le probléme rsulte dans la concentration des amtériaux lourds sur des zones de traitement qui en fait une véritable pollution All the bacteria are useful bacteria and none among all is pathogenic. All the bacteria play a role to play in the development and the management of the life on ground. Certain bacteria are there for the elimination of mayons weak, the natural selection of the life. Others are there to take part in the destructuring of the matter to enable him to be recycled, none is not pathogenic. Some live in corrosive conditions and must adapt to their medium. Concerning the heavy matériuax the ground needs some, the man rejects some and it is thus not a problem more than that. the problem rsulte in the concentration of amtériaux heavy on zones of treatment which in fact a true pollution

  15. Hi Titus, we produce a sunlight activated nanotechnology mesh that is capable of complete disinfection, destruction of chemical contaminants through and advanced oxidation process, and will remove heavy metals like lead, arsenic, mercury. It is implemented in various products, but at the household level we recommend the SolarBag, which has been deployed in 60 countries and last year was awarded the IWA's Global Honour award for long term village level household use in Africa. Send me an email at mark.owen@puralytics.com and I'd be glad to work with you. More on the SolarBag - http://www.puralytics.com/html/solarBagNGO.php

  17. 1. Prepare a rectifier 2. Make 2 pipes of different diameters 3. Put 1 inside, attached your anode end to the inner pipe 4. Attach your cathode end to the bigger pipe 5. As you switch on the rectifier, the Pb will adhere to the surfaces of the bigger pipe 6. The output of this pipe must undergo chlorination to eliminate pathogens. Hope this helps.

  18. Possible solution

    I agree with the previous post regarding identifying possible sources of lead contamination. Knowing the LSI of the water will indicate the corrosivity or scaling potential of the water. If lead soldered joints or pipe exist in the home than that could definitely be a source of the contamination if LSI indicates corrosive water; however if the contamination is coming from the distribution system that would be more difficult to address by eliminating the source. 

    There is a robust treatment system I used in the past called LINX Water Treatment system  http://www.linxwater.com/contact-us that goes under the sink similar to RO.  It is a cation / anion exchange membrane that is regenerated with electricity instead of salt. I believe it can operate on 50hz power. 

    Good Luck

     

     

  19. Hello Titus, I suggest to try to identify and remove the lead source and maybe you can treat or reduce it without the need of sophisticated treatment process. You can collaborate with the ministries in your region they must know where lead come from..maybe from industries, so they follow the requirement of treating their ww before discharge into streams or ground. In the houses: Lead can come from an old distribution system (lead pipes) and faucets and others.. so you can replace lead pipes into PE pipes etc,.. Lead can come from an old submersible pump ( if water is pumped from a deep well): it can be changed. What is the hardness level of your water? is it soft water? best

  21. Hello Mr Draleke. I agree with Mr. Xavier. But I understand your point too... people need a quick, cheap and efective solution now.... to avoid more health problems. So, my sugestion is the same then Sameer: Clorination wiht carbon adsorption. It is cheap, quick and easy. I really don't know how is gona be the efficiency of the treatment, But I really think that you can try. Try to use carbon block filters in each home, like this: http://www.omnipure.com/carbonTech.htm but remember: If you do first the clorination, the carbon block will also remove the free clorine from water... But if do first the filtration, the bacterial will grow in the filter... You can also do a big treatment system, with a UV system before the central filter (sand and Carbon), with a post clorinatin.... well, right me is you need to discuss more... Cya!

  22. Chlorination followed by Sand Filter and Granular Activated Carbon Filter

    You can try Chlorination followed by Sand Filter and Granular Activated Carbon (GAC) Filter for removal of both faecal and heavy metal (lead). Chlorination will disinfect the water. The sand filter will allow pre-filtration and reduce the TSS of he drinking water. GAC will remove residual chlorine as well as lead in the drinking water.

  23. Thank you Xavier for your comment! The lead (0.2mg/l) was detected in spring water (groundwater source) where the community collect their drinking water from. It is not contamination from home. Therefore, the solution we are looking for is removal of such chemicals and pathogens through water treatment preferably at household level. Best regards Titus

  24. Hello, the question is that does that lead in drinking water at home? I think first you have to avoid contaminating the waters, for after not having to decontaminate, perhaps the solution does not pass through the water decontamination, defend and excuse my technology, we can produce enough water in homes, for less expense than the cost of appropriately. It is cleaner, the cleaner but that is least dirty. Have a nice day!!