GreensandPlus water filter

I agree, greensand is an ion exchange media not a simple adsorbant. To adsorb one ion (like Mn or Fe) it releases an ion from the glauconite matrix. In order to reeverse this, you must add some kind of resorbant ion mix. Usually its KMnO4, but it could also be something like a specially formulated EDTA base.

There is no free lunch even in surface reactions

Farmerman,

Thanks for the reply. I thought greensand was a catalyst type media rather than an ion exchange like a softener.

I was given advice by a member here that this nwere version (GreensandPlus) needs to only backwash. I find that a very strange thing to say as the media removes not sediment as its purpose (this backwashing only can work) but removes iron and sulfur.

Therefore "just backwashing" wouldn't seem to work as the backwashing water (not from a twin tank system) contains the same problem water and the water used for treatment.

Thanks again,
Andy Christensen, CWS-II

Glauconite is the group mineral name that is contained in "Greensand". Its nomenclature was most recenly defined in the API Handbook of GEology , (which got its insert from Bailey, S. W. 1980, THE HANDBOOK OF CLAY AND CLAY MINERALS).

glauconite sands are mined in Delaware and NEw Jersey and in the coastal plain of MAssachussetts and Maine and New Hampshire. Chemical companies used to use glauconite as the model fro developing new ion exchange salts and resins . Its still used extensively in packing towers for municipal water supplies. (Usually they have 2 towers and they dont backwash, they rebbed the towers one at a time while they watch for breakthrough for iron and manganese. They will take the old greensand back and extract the exchanged ions.(They used to use it for packed beds to collect gold and platinum in water out west. The greensand was mixed with Rohm and Haas ion exchange resins.

Its neat stuff

I'm getting excellent results with FILOX.