What is the Best Treatment Option for Laundry Wastewater?

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The flow is around 500 m3/day for a laundry... The WW contains soap, softener and chlorine.

Which is the best and cost effective way to treat the WW?

Is reuse possible (to use again for the washing machines / irrigation..? 

Much appreciated

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19 Answers

  1. Cost of a wastewater treatment and reuse plant would need very careful investigation . Have you considered new washing machine technology like XEROS?  https://www.xerostech.com

    Reduce the water required by 70 percent. 

  4. It has already been said here:
    Step one is to look at your process.

    - Do you use the most water and energy efficient washing machines? Investing in more efficient machines could be cost-effective compared to a larger wastewater treatment.
    - What kind of softener do you use, fabric or water softener? If it is water softener, could you use rainwater as a soft water source?
    - Why do you use chlorine for bleaching? Could you use peroxide?
    - Are there direct reuse possibilities, e.g. storing the water of the last rinsing cycle and reusing it for the first rinsing of the next wash, storing the second rinsing and use it for washing without any treatment the next time? That would could your water demand roughly by half.

    Step two concerns energy
    How do you heat the laundry water? Do your machines accept hot and cold water? If not, install a respective device.
    Some of the laundry water will be very hot. You can use a heat exchanger to preheat the next hot water with the water from the washing machine. Cool the wastewater down to less than 5°C above your cold water in the heat exchanger.
    You can use solar collectors to top up the temperature to the final level.

    Step three is to treat the water for recycling.
    Laundry water is not very polluted, which is partly a problem. You can treat it with vertical flow constructed wetlands with quite a small footprint if you have some space outside. Otherwise we had also good results with multi-stage floating bed reactors. The bed is made of foam cubes where bacteria can attach, which increases their age and concentration in your treatment containers. Constructed wetlands provide the same effect.

  5. Dear Anojan,

    Yes it could be possible that you re use this wasteewaterafter a good tratment.
    I recommend you use peroxide or ozone instead of chlorine bleanch, and use a biological treatment to remove the organic contaminants, and any kind of good filtration system after this.

    The recicling water can be used if the economical and other convenient analysis (area, potable water cost, treatment cost, law requirement, other ones) point to that.

    Regards,

     

    Orlando D. Gutiérrez Coronado

    1 Comment

  6. Absolutely it can be done.  Our system works well on this tyoe of ww.

  7. A few months ago I did an experiment in my lab (Returning Waters Laboratory in Templeton, PA) with the help of the chemistry department at Indiana University of Pa that tested recycle laundry water filtered by a Matala grey water filter system versus a Aquasun cartridge filter system.  Neither system was satisfactory (basically toc and clarity problems).  I can send study results when write-up is complete.  I plan further studies on input control (detergent), filtration and treatment systems.  Suggestions welcomed.  DR. Tom Falcone

  9. Why do you use Chlorine? It's bleaching means you have only white to wash? You can use also peroxides. BTW the strong oxidants will have negative influence on microbiological processes.

    A DAF is a perfect solution to bring out the detergents and fine solids. The foaming sludge can be further reduced by filter press and the cake to landfill. 

    1 Comment

    1. Yes it is only white cloths... for a hotel... 

  10. Bonjour Toutes eaux usées contient de la pollution dissoute. Bio chimique, chimique.Il n'existe aucun traitement de purification efficace pour supprimer ces pollutions dissoutes. 

    Ce qui lmaisse entendre que tout recyclage d'une eau usée contenant de la pollution dissoute  dispersera dans l'environneemnt de la pollution. Recyclée sur un lavage, la toxicité du liquide augmentera et donc polluera encore plus l'environnement.

    Pour détgruire certaines pollutions c'est au tout départ de l'utilisation des produits qu'il faut agir.

    English

    Hello all wastewater contains dissolved pollution. Bio chemical, chemical. There is no effective purification treatment to suppress these dissolved pollution. 

    This suggests that any recycling of waste water containing dissolved pollution will disperse in the environment of pollution. Recycled on a wash, the toxicity of the liquid will increase and thus further polluted the environment.

    To avoid certain pollution it is at the very beginning of the use of the products to act.

  11. Yes it is very much possible that you recycle this water . Please shara water analysis report at rakesh@berspl.com

  12. This is my design for hospital's laundry house. Wastewater treatment and recycle plant cap. 400 m3/day.

    2 Comments

  13. You can also think of using constructed wetland technology, such as sub-surface flow. Works very well. Water should be tested upfront to check pH and main contaminants so as to use the most appropriate phytoremediating plants. Also works well to change to using alternative laundry detergents that are more natural  without containing parabens, phosphates, petrochemicals or sulfates.

    2 Comments

    1. the most appropriate phytoremediating plants. 

      Bonjour Yollandi Cela n'existe pas de plantes épuratoires. Tout végétal par son complexe racinaire absorbe uniquement que du liquide. Si ce liquide contient des polluant nocif pour la plante, celle ci va saturer et mourrir. Tout Vivant sur terre ne se nourrit que de Vivant. Le nourrir avec de la pollution est un crime contre l'humanité car tôt ou tard ce végétal saturé de polluant sera enterré dans le sol et restituera sa pollution contaminant l'environnement.

      Hello Yolandi

      There are no purifying plants. All vegetal by its root complex absorbs only liquid. If this liquid contains harmful pollutants to the plant, it will saturate and die. All living on Earth feeds only on living. Feeding it with pollution is a crime against humanity because sooner or later this saturated plant of pollutant will be buried in the soil and will restore its pollution contaminating the environment.

    2. A constructed wetland technology with floating plants works even better. The key question here is, does the laundry have land around it for the wetland? Regards to @ll

      1 Comment reply

      1. Thats the issue... they do not have that much land... 

  15. Dear AP.

    At best have the least amount of soap.detergent. etc in use. Use more hot water and bio-soaps ie made of veg. oil origin.

    Then opt for non mechanised biological  ETP ie only septic tank. with stone  pebble filters and in last stage have phyto r use of plants.

    Use fountain in the polishing stage and all water can be safely used for irrigation.

    Well wishes.

    Prof Ajit Seshadri 

  16. we prefer a biological solution.  it will be cheaper and there will be less stuff to haul away.  you want to avoid the use of chemicals.   We use a microbe reactor so you dont need to buy enzymes or microbes.  We prefer Chem5 that works well with laundry soap.  we treat it anaerobically and then aerobically, then pass through a phosphilter.  that takes away the bulk of the pain.  the phosphorus.  good luck.

    and yes, you can reuse the water

  17. Clay, EPI amine/ACH blend followed by an anionic polymer. 

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  18. probably the toilet or other sanitary system.