Zeomangan is formulated from a glauconite greensand and is capable of reducing iron, manganese and hydrogen sulfide from water through oxidation and filtration. Soluble iron and manganese are oxidized and precipitated by contact with higher oxides of manganese on the greensand granules. The hydrogen sulfide is reduced by oxidation to an insoluble sulfur precipitate. Precipitates are then filtered and removed by backwashing. When the oxidizing capacity power of the Manganese Greensand bed is exhausted. The importer in Bangladesh is Green Dot Limited ( www.greendotbd.com). It is available at Green Genesis Engineering Limited ( www.greengenesisbd.com ) , Heron Water Purifier ( www.heronwaterpurifier.com ) and The Water Shop bd ( www.watershopbd.com )