How to eliminate Sulfates from waste water effluents 3

[22854]

I would like to know which are the most used methods o technologies to eliminate or reduce sulfates contents from industrial waste water to comply with municipal regulations.

Main quantities of sulfates come from neutralizing basin of demin water plant and cooling water tower blow down.

 

[nareshiitr]

it has been realy nice going through all the postings. I am new to this website. I am working in a Env Engg company in india. we are recently a successful bidder for treating this type of wastewater in IOCL, india. Where the Consultants are going for wet air oxidation. But i think this is very expensive for highly concentrated wastewater.

Please let me know your views.

India

 

[JaccoH]

Dear Nareshiitr

I am not sure that I understand your posting, but are you saying that you can remova sulfate from water through wet air oxidation? That would be worth a price or two, or I am totally misunderstand your posting.
Could you please specify what kind of technology you have been succesful with and what wet air oxidation has to do with sulfate removal.

Jacco

 

[moltenmetal]

Nareshiitr is confused between sulphate and sulphide. Sulphide does react with oxygen under relatively mild conditions to produce sulphate and sulphur. The balance between sulphate and sulphur products is pH dependent. Hydrogen peroxide at room temperature is another option for sulphide, if you want to trade operating cost for capital cost.

Sulphate is rarely regulated in discharge permits in my experience, so the fact that the original poster's regulatory authority had sulphate on its list and then removed it is not surprising. It doesn't represent much of a toxicological issue. Usually it's covered under the catch-all of total dissolved solids (TDS).

 

[siretb]

I have heard that zeolithes even sodium alumino silicates can be used as way to reduce sulfates in waste waters.
Has anyone heard about that?

 

[kenvlach]

Yes, this is well-known, but I think organic resins are more efficient. The sulfate anion can be removed with a Cl-type anion exchanger:

SO[sub]4[/sub][sup]2-[/sup] + ACl[sub]2[/sub] --> ASO[sub]4[/sub] + 2 Cl[sup]-[/sup]

 

[DeltaCascade]

Then when you regenerate the resin where does the sulphate go?
Looks like this topic is pretty well beat up.
Keep smilin