ZLD for high total hardness wastewater

Dear All

We have a wastewater with Total Hardness  3900 , I want know what is the the best solution for Reach to ZLD .

we calculate softening with caustic-soda, but it consumes lots of chemicals and OPEX is too high .

Many Thanks

Taxonomy

• Zero Discharge
• Zero Liquid Discharge plants
• Water Hardness

9 Answers

1. Investigate a weak solution of sodium hexameta phosphate. We have had brilliant results on hard water.

2. Caustic & soda, oply is best option for hardness removal.Increase pH to 11.5 to 12.00 & add soda accourding to jar test.

3. Lime treatment is the cheapest solution for hardness reduction and ZLD.

4.  one solution use lime softening and EDR  achieve near 90% recovery of your waste water

5. If you can mail total water analysis report we can suggest you proper solution.

6. First,use NaCl  and Na2SO4 in pH 9 can remove most of the Ca2+,Mg2+,then add Na2CO3 or CO2.Remaining Ca2+ to reduce hardness. Its effect is better and opex is cheaper than caustic etc.

7. Hi Mahmud, this is Alan Lim from Royal HaskoningDHV (Singapore Office).

   I have briefly checked internally and we believe our Crystallization technology can help you. Write back to me at: Alan.lim@rhdhv.com

   We have some things to clarify before confirming if Crystallization is the answer you need.

8. Hi Mahmud, you may consider using lime for softening or soda ash (sodium carbonate).  These are generally much cheaper than caustic.  Feel free to download the STASOFT computer software freely available on the Water Research Commission's website (South Africa).  This allows you to select either of the chemicals for precipitation softening (not ion exchange or others such as that suggested by Richard) and gives you the amount required to achieve the level of hardness you want.  Inputs are pH, temperature, sodium, calcium, magnesium, chloride, sulphate, TDS and alkalinity.

   4 Comments

   1. try this url, then search for Stasoft V5.  http://search.wrc.org.za/#!/

   2. apologies that you could not locate the STASOFT software.  You can find it by first accessing the Water Research Commission website, then go to the Knowledge Hub, and then search for STASOFT V5.  I will also try to give the programme directly, but I do not think The Water Network will allow it.

      1 Comment reply

      1. My mail is qasempur@gmail.com if possible send to this address.Thanks 

   3.  Tanks a lot for reply .I cannot locate this software too if possible send addressees  to qasempur@gmail.com

   4. I cannot locate this software. Could you please post the url. Thank you.

9. We have some technology at Resourcesxtract that uses magnetic technology that has been successfully in treatment of waster water without chemicals