How to reduce manganese level from drinking water?

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Hello everyone!

My company is responsible for managing drinking water quality for 96 water wells in Romania. Some of these wells have high level of manganese (aprox. 100 μg/l), higher than the permissible value.

I need a solution to reduce the level of manganese from these water wells.

Please send me your suggestion for this problem.

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44 Answers

  5. Dear Mandalin,

     

    One of the strongest oxidant you can use, and I suppose one of the best for this projec (depending onthe size of the system) is ozone.

     

    This could be ther first step before a filtation or better even a micro-filtration.

     

    Regards,

     

    Orlando D. Gutiérrez Coronado

  6. 100 micrograms per litre is not very high. A simple water treatment system with potassium permanganate dosing followed by sand filtration will do. We've been designing and building such systems for municipalities and the industry as well. Feel free to contact me.

    Regards,

    Benedek

  9. Hello Laurent, As you see by my picture here on the side I am sitting with one of my old friends, who is a chief in Ghana, where I live and work almost half of each year.  In my companies in the states we have developed two technologies that deal with your problem.  The first and most economical is Electro-coagulation, which is a technology that operates off of a simple 110 volt electric system.  Go to www.eco-web.com  then Editorials tab and finally Authors tab and go to the 9th to the 12th papers and you can read about it.  Also on that same site is a white paper on our technology called the Plasma Incubator Reactor.  It is more expensive but it can handle the entire sewage output of a small city in Africa, to read about it go to www.abescousin1.com  or email me a gerrybeagles@aol.com  and my US phone is 916-877-1553.

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  11. Agree with Mr. Prem and Mr. Hariharan totally. We can reduce it , followed by adsorption filters as mentioned below.

  12. Agree with Prem Baboo. Oxidation using KMnO4 solution at high pH (>8, so you may need lime solution dosing prior to KMnO4) and filtration using anthracite is the common practise in some potable water treatment plants in South East Asia.

  14. Dear Madalin Negu

    Manganese Treatment  in Drinking water
     

    Ion Exchange  
    Ion exchange can remove small amounts of soluble manganese from water. Potassium chloride may be used to regenerate the resin beads instead of sodium chloride if the added sodium is of concern.


    Oxidizing Filters  


    Oxidizing filters can remove up to 15-25 mg/L of combined concentrations of Manganese. Greensand, anthracite sand, natural or synthetic zeolites are used in a mixed media or a pressure filter. Potassium permanganate (KMnO4) is used to coat greensand and anthrasand with manganese oxide, giving it a catalytic effect. This coating oxidizes and removes Manganese usually without requiring an additional oxidation/precipitation step. The coating can be maintained either by a continuous potassium permanganate feed or by backwashing at set intervals with a potassium permanganate solution. 

    Natural and synthetic zeolite filter media have a catalytic effect that does not require chemical backwashing to remove the precipitate. The filter media may use venturi air injection as an oxidant, with an air relief valve that bleeds off excess air.

    Oxidizing filters can be used with ferrous or ferric iron, and manganous or manganic manganese. The minimum pH is 7.0. A pH of 8.0 is needed when the manganese concentration is high.

    Filtration  


    Filtration is the most common method of removing  manganese after oxidation. Slow sand filters, bag or cartridge filters, pressure filters, or conventional filters can remove the oxidized contaminants. Slow sand filters and conventional filters are the most expensive alternatives and are not normally used for removing Manganese unless colloidal particles, bacteria, or other filterable contaminants are present. Bag or cartridge filters have a very low capital cost, but higher maintenance cost in filter replacement. Automatically backwashing pressure filters have a higher capital cost and a lower maintenance cost. 

    regards,

    Prem Baboo

     

    1 Comment

  15. Dear Madalin

    Natural source of Manganese is more common in deeper wells where the water has been in contact with rock for a longer time. Manganese is not health concerns in drinking water. Instead, Mn is secondary or recommended drinking water standards because they cause aesthetic problems that make the water undesirable to use in the home and a bitter metallic taste that can make the water unpleasant to drink for humans . The US Environmental Protection Agency has a secondary standard of mangneese is 0.05 mg/l,

    The Manganese Treatment Process.

    1. Oxidation Followed by Filtration

    the most effective treatment involves oxidation followed by filtration. In this process, a chemical is added to convert any dissolved manganese into the solid, oxidized forms that can then be easily filtered from the water. Stronger oxidants can be used in complement such as chlorine dioxide (ClO2), chlorine (Cl2), potassium permanganate (KMnO4) or ozone (O3).
    Chlorine is most commonly used as the oxidant although potassium permanganate and hydrogen peroxide can also be used

    Mn2+( Oxidation) = Mn4+ (Precipitaion) =MnO2

    1. Oxidizing Filters

    Oxidizing filters oxidize and filter manganese in one unit. The filter is usually comprised of manganese treated greensand. In the case of a manganese greensand filter, the filter media is treated with potassium permanganate to form a coating that oxidizes the dissolved iron and manganese and then filters them out of the water. Because these units combine oxidation and filtration, they can be used to treat raw water with dissolved and/or oxidized manganese.

    1. Other Treatment Methods

    The methods described above are the most common processes for removing manganese but others like aeration, ozonation, and catalytic carbon may also be effective. While these units may successfully manganese, their cost should be carefully compared with more traditional treatment methods and, as always, you should obtain a written guarantee of their effectiveness.


    Biological removal

    In the same way manganese can be removed by biological way. There are bacteria which take their energy from the oxidation of manganese and which require a water with specific conditions to have an optimal activity of the micro-organisms. However, even if it is possible to carry out in the same time the manganese removal by physical-chemical treatment, the same doesn’t go for the biological way. In fact, the manganese specific bacteria need different environmental conditions.

    Regards,

    Prem Baboo


  19. We can extrapolate for days on this matter if we do not have all the needed parameters like pH, maximum flow rate, water analysis. Since that you have many well locations to treat I still believe that the most cheapest way to treat these wells will be ion exchange if the pH is suitable. We had some cases, here in Quebec, with manganese level up to 35 mg/l treated that way and since that you treat the manganous form there is no need to add another step like filtration to complete the process. The only maintenance cost will be usage of NaCl and resin cleaner once in a while.

  20. Unfortunately air is not very effective in oxidising manganese and works better for elevated iron to oxidise the iron. There are a few options that you can look at. You can oxidise the manganese with potassium permangante. Manganese greensand (Maddox) is definitely also a possibility. Especially if you have existing sand filters. You will just have to regenerate the filter media and that can be done with potassium permanganate. Another possibility is biological manganese removal. For this to work you need to get your pH to a certain level while the dissolved oxygen levels are also important. It may be possible to simply add a pH step to your current plant and inject oxygen in the water (if the DO is not adequate) such that you can get the desired conditions on your filter media for the organisms to grow. We have recently commissioned a biological iron and manganese removal plant. It works very well but where you have iron and manganese, you need 2 steps in series due to the fact that for Mn removal you need to raise the pH and control the DO levels. The same is not true for Fe removal which is generally much simpler.

  22. I agree with oxidation followed by filtration of the manganese flock. You state that the water source is well water therefore I believe there are no organics in the water. If you do have organics it will take more time for the oxitation to complete its job.

  23. Removal of manganese is generally a two step process -- first an oxidation step followed by physcial removal. The chemistry of manganese is complex. Oxygen will not oxidize Mn(II) to Mn(IV). To do that, you need a stronger oxidant -- HOCl, ClO2, MnO4, O3, ferrate, etc. The oxidation step is generally pretty fast, on the order of minutes. However, getting the resultant particualtes to grow so that they are easily removaed by clarification is often more dependent on pH, especially with chlorine. It is less dependent on ph with stronger oxidants like permanganate and ozone. There are many available resources, including some excellent ones by Dr. Bill Knocke of Virginia Tech (see the Water Research Foundation website for these reports)

  24. Madalin: Maddox is an Ion Exchange Granular Catalyst of excelent performance in Iron & Manganese, with two decades of development and improvement and successfully operating in many countries. Visit my webpage "mts-fsc.com" , in Spanish but with links to the south african manuifacturing company. Contact me for any questions you may have. fsanchezmts@yahoo.com

  28. To remove manganese you need to make an oxidation from Mn+2 to Mn+4, but Mn not easily oxidized in natural water pH range (7-8), & need much more contact time, but at pH not less than 9 it easly & rapidly oxidizied, so that firstly you need to raise water pH using forexample (sodium carbonate), then using an oxidizing agent like Cl2, ClO2, Kmno4 and the precipitation will be MnO2 and you can remove this with sand filters.

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  33. The proceed water should be oxidized by using chlorodioxide. Then you have to dose inorganic coagulant according to sand fülter fulux. I recommend you use serial connected 2 sand filters based on 10-15 unit flow rate. Then use activated carbon filters. ..

    I had similiar problem; 5 ppm iron- around 1,5 ppm manganese and 2,5 ppm copper ions for raw water. Before RO plant , iron, manganese and copper contents are dropping 0,02 ppm with 2 sand filters + 2 activated carbon filters dosing chemicals.. If you want I can prepare technical project according to current rawwater analysis results.

  34. You have all the answers below. However, it is important to know the pH level of the water, because this influences the oxidation of Manganese. pH will also influence the kind of approach applied, but oxidation and precipitation is a good way of removing the Manganese

  35. As Suko nv of Belgium we represent a zeolite manufacturer of the US. The Crystal Right filter media is commonly used on mostly well waters to remove hardness, manganese and iron (Fe2+ form only) and also adsorbs ammonia out of the water and CO2 which corrects the pH of the water to neutral. We have been on the market for more than 35 years with this and are meeting all requirements of our customers. Please do not hesitate to contact me for more info or other support. Info@suko.be

    1 Comment

    1. Dear Peter,Thank you for your solution.Tell me please how to use the Crystal Right filter and what quantity we need to use to have good results.
      Best regards,Madalin Neagu

      1 Comment reply

      1. Dear Madalin, best is to send me a water analysis from all the wells and the hourly volume of water to treat. So we can calculate and make you a suggestion for sizing the system. info@suko.be

  36. Manganese ions in water supplies can cause stained clothes, "black" water, water main encrustation, deposit on paper machines and debris at end user taps. Though chlorine can be used to control these problems, it reacts so slowly that manganese ions may still be in the water distribution after 24 hours. Chlorine Dioxide reacts much more rapidly with manganese, oxidizing it to manganese dioxide. After 5 mins contact time 99+% of manganese dioxide can be removed with 0.45 micron filter.

  40. Can you provide more info on pH, hardness and iron level. At a pH around 7 the manganese which is in the manganous form, could be remove with a cation resin easily and will also remove hardness and iron if it is in ferrous form

  42. Managnese is not dangerous for health but must be removed because it gives a dark color and steel smell to the water.

    To remove manganese you need to make an oxidation from Mn+2 to Mn+4 and the precipitation will be MnO2 and you can remove this with sand filters.

    Oxidation with oxygen some time is not sufficient and you can add chemical reagents like : ClO2, Cl2, KMnO4 or O2.

    1 Comment

  44. Dear Madalin

    The most common way to remove Iron and manganese from water is by oxidizing the manganous and ferrous ions followed by precipitate removal by settling and filtration. Oxidation could be physically by air induction and / or chemically by permenganate dosing

    1 Comment