I have thoroughly researched non-chemical removal of manganese from water with a ph of 7.1.
What I need for a filter media is mined manganese dioxide, often sold in the West under the tradenames, Pro-OX™, Pyrolox™, Filox™, and MangOx™. These are granules of solid manganese dioxide.
Manganese "greensand" is not the same. Its granules are only coated with a thin layer of manganese oxide and it needs periodic chemical regeneration with potassium permanganate, where the mined manganese dioxide does not. Birm does not need regeneration and works great for iron removal at a ph of 7.1, but for manganese, the ph would have to be raised to 8.5-9.
Everybody in every shop I have gone into purports to know everything about water filtration, but upon questioning, it quickly becomes apparent that they do not know anything at all about water chemistry. It has been very frustrating.
In all the filtering shops they say, "We have 'manganese,' this one right here." Manganese what? It sure as shit is not elemental manganese. Is it manganese dioxide? Is it manganese greeensand? The labels are inconclusive. They never heard of chemical regeneration or potassium permanganate. Mention of these things gets only blank stares. Yet manganese greensand will stop working after about only a month without chemical regeneration, despite their claims that it's good for three years. What are these people selling?
I am located in Phitsanulok, but that's irrelevant. does anybody know where to purchase mined solid manganese dioxide ANYWHERE in Thailand, preferably under one of the the trade names mentioned above?