Patents by Inventor Dmitry A. Topchiev

Dmitry A. Topchiev has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for the purification of waste water containing silver
    Patent number: 5423990
    Abstract: A process is disclosed for the purification of waste water containing a silver compound, comprising the steps of (1) adding to said waste water a salt of a poly(guanidine) or poly(biguanidine) polymer (2) adding a flocculant, and (3) filtrating the formed flocculate.The invention is particularly suitable for the removal of silver from the effluent of a photographic processor, and more specifically the effluent of a processor of wash-off materials, said effluent also containing gelatin.A most preferred poly(guanidine) compound is poly(hexamethyleneguanidine) hydrochloride.
    Type: Grant
    Filed: December 30, 1993
    Date of Patent: June 13, 1995
    Assignee: AGFA-Gevaert, N.V.
    Inventors: Eddy Michiels, Frank Michiels, Dmitry A. Topchiev, Gennady G. Kardash