First are you confident dissolved sulfur is the problem? I ask because in my neck of the woods actual sulfur is rarely the real source of the problem. Other things like anode rods or bacterias can also produce sulfur or sulfur smells. Make sulfur is your problem before you pay out money treating for it.
Aeration is crap, avoid it. It is a last resort for problems that companies like to sell as a fix all solution for many water issues. Overall it causes more problems then it solves.
Activated carbon can also take out sulfur but it’s capacity to do so is limited. It can only absorb so much before it’s life is exhausted. In very low levels of sulfur the cheapest and easiest solution is a carbon cartridge filter. Measurements and price analysis must be made. IE if a cartridge has the capacity to take all your sulfur out for 2 months it’s a good idea. If the amount in your water is such that it lasts 2 days a 30 dollar cartridge every 2 days is a bad solution.
Greensand will depend on the amount of sulfur and the other qualities of the water. It can be a solution, but is not a good one for all waters, the right conditions must be there. This would be the lowest maintenance solution. The greensand is charged with a powerful oxidizer potassium permanganate. It changes the state of various minerals and allows for physical filtration, which greensand is also very good at. Maintenance required is occasionally adding purple powder to a bicket sized tank.
Chlorination is the most flexible solution. It works in a wide variety of water conditions. Two basic types are chemical feed and chlorinating canister. When using chlorine you are forcing the sulfur out of the water into a solid state, so it has to go somewhere.
I’d advise against chemical feed pumps. they have many similarity in sales and performance to Aeration systems. A chemical feed would allow for the minimal amount of chlorine to combat the sulfur. It pumps a set amount of chlorine into the water as it is run. Ideally a balance to be enough to knock out the sulfur but not enough to be noticed. Maintenance is occasional adding liquid chlorine to a tank. Sometime the pumps may be followed by a physical filter or a carbon filter(which to a lesser degree is also a physical filter).
With a chlorinating canister you are using chlorine pellets not unlike(or in some cases the same) the pellets many people use for their pools. The water flows through the pellets and is chlorinated to it’s maximum potential, thus forcing any sulfur out. After the canister is a carbon filter, I recommend a large permanent one but I’ve know some companies to simply follow up with a cartridge filter. Maintenance for this type of system is required every 6 months to a year, sometimes longer duration is based on water quality. For maintenance the canister has to be dissembled and thoroughly cleaned and new pellets added. When I started working for a water treatment company we used to provide instructions for customers to do this themselves, so it is within some peoples capacities, these days we recommend all customers hire a professional to do this for safety and liabity reasons. Meaning a 200 dollar service call is needed periodically
Not all customers could follow instructions well resulting in many problems, such as chemical burns from poor handling of the unit/pellets, melted canisters/parts due to people mixing incompatible pellets, and poor flow due to people not being complete in the cleaning. Thus we gave up on trying to save people from paying for those service calls.
Back to activated carbon again. Carbons capacity for sulfur is limited, it can take out a set level of sulfur measured in pounds. Carbons capacity for chlorine however is measured in tons. Which is why you would first treat the sulfur with chlorine, then use the the carbon to treat the chlorine problem.
I’m sorry this is broken up and probably doesn’t read well. I’ve been handling other stuff and tabbing back periodically.
In summary,
You need to find a professional in your area familiar with treatment of sulfur. They need to be honest reliable and able to service the equipment in the future.
That person needs to confirm your problem is sulfur.
My recommendation for treatment is:
If a carbon cartridge is sufficient and economical use it.
Baring that use greensand if the right conditions are met.
After that consider a chlorinating canister followed by carbon.
Aeration and chemical feed are poor choices I’d avoid them if possible.
Good luck.