greensand filter question 1

[jenbes]

First, I would like to say there are a lot of helpful and smart people on this board.

I have a new well, plagued with the smell of rotten eggs. I have been told by salesman my h2s is .5 - 2 ppm.

I didn't necessarily want to add chlorine to the water. I was considering using the manganese greensand filter to remove the sulfides and the iron & manganese in the water. My concerns are with the KMnO4 needed to regenerate the resins. I was told the excess KMnO4 will be washed away during the backwash. Is this true? even with the IR method?

I have small children in the house, how do I know the KMnO4 is completely removed from the system? I'd like to be able to drink the water.

The independent test results are.

Manganese .013 mgl
iron .459 mgl
sulfide .05 mgl
sulfate 307 mgl
PH 7.2

I do have a water softener.
Thanks!

 

[kenvlach]

Potassium permanganate is one of the least hazardous water treatment chemicals. It forms highly colored solutions, so is easy to detect, and dilute aqueous solutions of KMnO4 are not considered very dangerous. Based on data from testing of rats (see MSDS link, bottom), a 50-kg person would have to drink 99 gallons of the 100 ppm solution (shown at far right below) for a 50% chance of death. The water overdose would kill you first!

The picture above demonstrates this color with permanganate concentrations ranging from 0.5 to 100 parts per million (ppm).

http://www.caruschem.com/permanganate.htm

See also the Wikipedia article

http://en.wikipedia.org/wiki/Potassium_permanganate

and an MSDS for potassium permanganate solutions:

http://www.jtbaker.com/msds/englishhtml/p6008.htm

 

[bimr]

You may want to refer to the discussion on thread164-165833 as hydrogen sulfide is discussed there as well.

Greensand filters are generally used for iron and manganese removal and can be used to remove up to 2-3 mg/L of hydrogen sulfide.

The potassium permanganate solution is an irritant and poison that must be handled and stored with standard chemical handling procedures.

The higher the concentration of hydrogen sulfide, the more frequently the greensand unit will need regeneration and backwashing.

The excess KMnO4 does wash away during the regeneration process. You can confirm the excess KMnO4 is washed out by the absence of color as kenvlach points out.

http://resources.cas.psu.edu/WaterResources/pdfs/HydrogenSulfide.pdf