Sulfur in geothermal spring...trying to create drinkable water

[griffrob]

Our group was contacted about cleaning water from a geothermal spring. The current problem with the water is the high levels of sulfide in the water, present by the rotten egg smell around the water, and the white mineralization within the water canals.

Our design uses a system of oxygenation and chlorination to remove the sulfide from the water. Water was being pumped from the source of the spring to local barrels. The water then was subjected to oxygenation by forcing in through a showerhead that sprayed directly into rain barrels. Inside the rain barrels is where chlorine was designed to be added and the sulfide allowed to precipitate.

Our concern about this design is the high levels of chlorine we calculated is needed to precipitate out the levels of sulfide. Through rough measurements using basic test strips for sulfide, the quantity present within the untreated water is around 20 to 30 ppm. Our group is trying to design a system that the local population can easily maintain, and is cheap. Are there any suggestions?

Thank you in advance for your help.

 

[bimr]

The first thing that you need to obtain is a complete water analysis. Without a water analysis, you are working in the dark.

 

[kjmastaw]

Hi griffrob,

I agree with bimr. Your calculation of chlorine demand may actually be low because there may be other constituents which may use up chlorine before it gets to the sulfides. Air stripping, manganese greensand filtration and activated carbon are a few other options to consider.

Regards,
Kevin

 

[griffrob]

Thank you for your advice. In response to bimr we are sending a sample to the local lab to get fully analyzed but we were just concerned with initial readings of sulfide concentration because they were a lot higher than anticipated.

kjmastaw, we had considered doing a manganese greensand filter but we had two problems with it. It required a little more technical knowhow for the locals, and it becomes ineffective once the pH is not neutral. Our water unfortunately is not neutral. Also we were thinking about using aeration combined with chlorination, because of the high concentrations of sulfide. After reading up on the air stripping we were under the impression that it only removed low concentrations of sulfide and not the higher concentrations.

 

[bimr]

This subject has been discussed in previous posts. Refer to the following posts:

http://www.eng-tips.com/viewthread.cfm?qid=272029

http://www.eng-tips.com/viewthread.cfm?qid=252943

http://www.eng-tips.com/viewthread.cfm?qid=218491

It is difficult to remove the sulfur in a cost effective manner and there are tradeoffs that must be considered when selecting the treatment technology.

 

[kjmastaw]

Here's another idea to consider. We've found peroxide dosing to be effective at higher concentrations.

Nix the air stripping idea. It was one I threw out there without thinking.