Hydrogen sulfide removal and elemental sulfur

[rnancarrow]

My client has water supply wells in limestone with H2S average of 2.3 mg/l. The average iron is 227 ug/l and ranges from 170 to 1730 ug/l, with the highest iron associated with highest H2S. I suspect iron bacteria/sulfate reducers in the well and formation. They are chlorinating directly after the well and precipitating elemental sulfur. Can the sulfur be filtered by cartridge filtration, or does it need special media? pH of the raw water is about 8.2, with a mean LSI of negative 0.24. I am going to use UV for the primary disinfectant and NaOCl for residual. The UV needs a NSF65 filter, so I was hoping to take out the S there, but am not sure of mass of S generated and what sizes particulate could be?

Any ideas woul be appreciated!

Thanks

 

[GarySCWSVI]

Yes the sulfur can be filtered by cartridge filtration, however, since the chlorination process will also cause colloidal particulate you may need to use sub-micron cartridges. Another filtration process like a Multi-media filter (sand, anthracite and garnet) preceded by coagulation using alum or a polymer may be necessary. Use of either process would depend upon volume of water to be filtered and the amount of particulate to be filtered. I would opt for the Multi-media filter w/coagulation.

 

[MAJOSA]

Dear Rnancarrow, Check out "

http://www.zeolife.co.uk"

they manufacture bespoke H2S removal systems using Natural Zeolite, no chemical dosing just Natural Adsorption.
Majosa

 

[ozfish]

You can remove the H2S prior to the chlorination with an efficient aerator. Try visiting

http://www.akvastroiservis.com/

they have an aerator manufactured in Australia that willdo the job. See the case studies on their web site.

 

[bimr]

The resulting oxidized sulfur particles after the chlorination may be colloidal. So I will concur with GarySCWSVI that a filtration process like a multi-media filter (sand, anthracite and garnet) preceded by coagulation using alum or a polymer is the recommended treatment approach.

Removal of hydrogen sulfide by aeration is not typically successful unless the pH is acidic or the hydrogen sulfide content is minimal. Such waters are rare. Sulfur waters tend to have significant quantities of alkalinity. At a pH of 8.2, only about 5% of the total sulfide is present as hydrogen sulfide. The rest is present as an alkaline sulfide.