Verfahren zur Keimbefreiung von Wasser

292,099. Adler, O., and Adler, R. June 13, 1927, [Convention date]. Addition to 286,338. Purifying liquids.-In the process of de-chlorinating water by passing it through or over coarse pieces of carbonaceous material, as described in the parent Specification, the water is first caused to flow over substances insoluble in water, resistant to free chlorine and having the property, in the presence of chlorine, of precipitating and retaining salts of iron, manganese, and other heavy metals. Manganese peroxide, manganous acid, ferric oxide, and the carbonates of the alkaline earths are mentioned as suitable substances. They can be used in pulverulent or granular form, or precipitated on solid bodies, such as sand, pumice stone, tuff, or natural or artificial zeolite. They may be mixed with the porous material, used, in the process of the parent Specification, to obstruct the passage of bacilli. The compounds of the heavy metals retained by the substances may be removed from time to time bv a reverse flow of water. The precipitation of the salts of the heavy metals tends to increase the hydrogenion concentration and, to neutralize this, materials, such as limestone, chalk, marble, or bauxite may be mixed with the carbonaceous matter, or the water may be caused to flow through such materials after passing through the carbonaceous matter.