Sulfate in well water

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 My well water has a high level of sulfates. I have been told that I need a reverse osmosis system to clean it. what can I do with the waste water? I live in a remote arid location. Could I use mycelium to deal with it? Could I grow mushrooms with this water? Or perhaps a wetland? I have plenty of space

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9 Answers

  1. High sulfate water can lead to the formation of hydrogen sulfide (H₂S), causing a rotten-egg odor and degrading water quality. A structured treatment approach can effectively remove sulfides, control sulfate levels, and produce potable water.

    ThioBacteria play a crucial role in oxidizing toxic sulfides into sulfates (SO₄²⁻), preventing hydrogen sulfide generation and eliminating odors. Once converted, lime (Ca(OH)₂) is added to precipitate calcium sulfate (CaSO₄), which is then removed as sludge.

    To achieve drinking water quality, reverse osmosis (RO) membranes filter out residual sulfates, though this process requires electricity and generates sludge and brine, which require proper disposal.

    Beyond purification, high-sulfate water can be repurposed for sustainable agriculture. Certain plants naturally absorb sulfates, reducing their concentrations over time. Reeds (Phragmites australis) are commonly used in constructed wetlands to absorb excess sulfates, while Vetiver grass is effective in phytoremediation. Mustard and cabbage (Brassica species) accumulate sulfur compounds, making them suitable for sulfate-rich environments. 
    Integrate  biological treatment, chemical precipitation, membrane filtration, and plant-based remediation, we can transform sulfate-contaminated water into a valuable resource while promoting sustainability and environmental restoration. 

  2. We have an easy DIY system that can fix this with typically no reject water.  Our finished water is great for mushrooms.

  4. Check out the “Omega Project”. Wastewater and algae. Prof. Jonathan Trent.

    1 Comment

    1. I think that is more for sewage. The water I want to treat is from a borehole that has been through a RO system and would then be even higher in sulfates. Before I put it on the land should I process it in some way? 

  5. High sulfates in water leaves a bitter or medicinal taste and has laxative effects – diarrhea and dehydration in those not used to high sulfate (sulfate levels of lower than 500 mg/L makes infant formula.  Even animals present similar results.  They also corrode plumbing (copper particularly) – plastic pipe are more resistant.  There are four types of treatment:

    1. Reverse osmosis:  Membrane pores stop even sulfate and ensures 93-99 percent removal.
    2. Distillation: Steam rises and leaves contaminants (Sulfates) behind. – 100% sulfate removal.
    3. Anion exchange: most common method – for commercial, livestock and public supplies – not common for households.  Replaces negatives charged (sulfates) with sodium chloride/Potassium chloride
    4. Adsorptive media filtration: Charged media bed that can force ions (Sulfate, opposite charge) to be pulled out of water to attach it to media.

    Sulfates do have wider application in industries – Gypsum, Copper sulfate, Iron sulfate, Magnesium sulfate etc,.  They are salts of sulphuric acid.  In case you have no option to dispose, please store it for a while before disposing it in the nearby city.

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  6. The best recommendations are for either ion exchange or ultrafiltration (reverse osmosis).  The reverse osmosis would be more problematic in my view as it requires higher continuous pressures.  It would be considered if the availability or consumption of the ion exchange materials (NOT the same as those in water-softening systems!!) made it more expensive than the power/pump costs.  In either case I would not expect the waste stream sulfate concentrations to adversely affect the existing levels if they are already high in your well water.  To remove it would require reaction, most likely with calcium to produce gypsum, but short of commercial volumes that might not be an improvement.

    BOILING is also energy intensive, but would also eliminate any sulfur gases (rotten egg smell) as well as the sulfates.  A SOLAR STILL could be used in some locations to get around that problem, but I'm not sure what the flow rates would be.

  7. Yes reverse osmosis may remove up to 99% max of sulfur but the rotten egg smell may linger on despite.

    You may want to find out the origin of your sulfur, usual suspects: industrial, agricultural runoff as well as leaching from old abandoned sites. For your waste water:

    for lack of organised minicipal waste disposal try a septic tank where you separate grey from black water and reuse. Grey water: from shower, kitchen and laundry use funnel into a series of pools planted with native grass vegetation soaking up and cleaning the water usually two to three pools/ponds benefitting local wildlife in addition. This grey water may be reused for another round of shower and laundry use. Blackwater store in poop container and re-filter into more containers en suite, then eventually channel into separate leachfield or for use as high concentration plant food into separate pond area where plants take up and fikter this material as well.

    good luck ket me know how it goes.

    1 Comment

    1. My house is in the mountains. There has been a drought here in Catalonia. There is no smell at all. I have a septic tank. All the waste water from the house goes there. I would like to know what to do with the waste water from the RO system as it (presumably) will be very concentrated with Sulfates?

  8. Recommended maximum sulphate levels in drinking water is generally 250 mg/L.  Levels above this can be tolerated; however, if you are not used to drinking water with elevated sulphate concentrations you can overstimulate some bacteria in your intestine and it can be painful.  Infant formula should not use water with greater than 500 mg/L.  Ion exchange and reverse osmosis can remove sulphate.  Reverse osmosis requires extremely high pressure, so I doubt point-of-use (at the tap) household RO treatment systems achieve RO treatment.  If you buy one, make sure it has been NSF tested and certified for sulphate removal.  Ion exchange involves adsorbing sulphate and typically releasing sodium, plus you will need to regenerate the IO resin once it’s absorptive capacity has been reached.  Both technologies will generate a brine waste stream with elevated sulphate concentrations.  Sulphur is an essential nutrient in crop production and extremely high concentrations of sulphate are applied to large crops in the form of ammonium sulphate - so you don’t have to worry about releasing the sulphate reject to the wetlands or other vegetative areas - or simply release it to ground. 

    1 Comment

    1. Thank you Troy. That is very helpful. The water analysis just said sulfates. So how would I know if it is the correct type of sulphate to water crops with? I'm have no idea about chemistry! I failed it at school. 

  9. How much reject water do you obtain? Check with your state university agr school. They might have some suggestions on reuse of the high sulfate water so you don't just waste it.

    1 Comment

    1. Thank you. The system is not installed yet. I am trying to arrange soon. I might just get another analysis done first. The borehole was dug over 4 years ago. The builder only ran the water recently for a bout 10 mins before taking the sample. Perhaps it needed to run for longer. The water does not smell.

      2 Comment replies

      2. Sulphates SO4-- didn't smell, The smell is from Sulfides S-- as an anaerob degrade of sulphates. For Sulphate removal is a Nanofiltration good enough removes over 95% of Sulphates. You have ask the Reverse Osmosis supplier to change the RO Module to a Nano Module, needs also lower pressure around 40 to 50 psig. the concentrate you can use for toilet car washing etc. Needs a storage tank and pump and to avoid anaerobic reaction in this tank use a small air-aquarium pump with this bubble stone to avoid anaerobic water. This storage tank should be also connected to your rainfall pipes. Let's your contractor check with his experience the size of this tank.

         

        BTW other sulotion, use your Nanofiltration only for DRINKING water the rest for dishwasher, toilet, shower, washing machine etc. etc. ea. person needs max. 5 l/day (hard work outside)