Patent ID: 8658563

Claim:
A method for sorbent production, primarily for removing arsenic from drinking water, comprising the steps of saturating a moisture-absorbent, wettable organic support material with the aqueous solution of a water-soluble ferric salt, then filtering it and drying it to constant weight, saturating the support material with a stoichiometric quantity (computed relative to the iron content of the support material) of oxalic acid and/or water-soluble salt of oxalic acid, then filtering it and drying it to constant weight, while converting the iron ions to insoluble ferric oxalate, converting the saturated support material to activated carbon by anaerobic heating, then subjecting said saturated support material to anaerobic cooling, while the ferric oxalate is decomposed into iron and carbon dioxide, preoxidizing iron particles of the activated carbon by a water-soluble peroxide compound, filtering the activated carbon, and rinsing it to completely remove salt therefrom, then filtering it again and drying it, and converting the iron hydroxide formed on the surface of the iron particles into magnetite by anaerobic heating of the activated carbon, and subsequently cooling in an anaerobic manner the thus produced sorbent to room temperature.