sulfur odor and taste in well water

get the water tested first, dont buy some off the shelf unit because Sulfur or H2S can have many causes and therefore many possible (correct) treatments. One of the easiest is to chlorinate the water. It will precipitate the Sulfur and , you will need a sand filter to cathch the precipitate. The sand filter needs an auto backwash feature. .Other techniques include oxidation, areation and even adsorption in carbon beds. However, just buying a unit and not knowing the cause of your sulfur problem could be wasting your money.

Nope. No softener removes that gas.

A single Catalytic carbon or Filox filter can do the job without chlorination...

if the H2S is from a soluble source (like iron pyrites), GA carbon will only remove about 20%. Please get a water analysis before buying a system blindly.

Water testing is a given... Catalytic Carbon is not plain jane GAC.

Cat-C that Im familiar with is Granulated Anthracite media. Its catalytic in that it uses adsorption along with heavy meatals in the caol to catalyze the H2S.
Still, the H2S can come in several forms from conservative to colloidal and bacterial.
The cheapest is always oxidation and Cl is the cheapest oxideizer.

Is the ASTM standard for cat Carbon 6646? I dont have a new 09 standards book yet.