Abstract: To prevent biological fouling in an electrodialysis device, an electrodialysis device including a membrane electrolysis stack are created. Every membrane electrolysis stack comprises membranes stacked on top of each other and respectively dilute and concentrate compartments arranged therebetween, at least one first and at least one second membrane alternating in succession in the membrane electrolysis stack. At least one first membrane is selected from a group comprising an anion exchange membrane and a bipolar membrane, and at least one second membrane is selected from a group comprising a monoselective anion exchange membrane, a monoselective cation exchange membrane and a proton-selective exchange membrane, with the proviso that the second membranes are respectively selected independently of each other and that at least one first membrane in the membrane electrolysis stack is a bipolar membrane.

Abstract: To achieve high efficiency in regeneration of waste fluid from metal plating electrolytes for example, a device and a method for recovering a recovering material from a recovering fluid containing the recovering material are provided.

Abstract: The invention provides a process for depositing metallic layers from acidic or alkaline zinc or zinc alloy baths containing organic additives selected from brighteners, surfactants and complexing agents, a soluble zinc salt and optionally further metal salts selected from Fe, Ni, Co, Sn salts, wherein the bath can be purified continuously so that the process can be operated without interruption, as well as apparatus for carrying out this process.

Abstract: To prevent biological fouling in an electrodialysis device, an electrodialysis device including a membrane electrolysis stack are created. Every membrane electrolysis stack comprises membranes stacked on top of each other and respectively dilute and concentrate compartments arranged therebetween, at least one first and at least one second membrane alternating in succession in the membrane electrolysis stack. At least one first membrane is selected from a group comprising an anion exchange membrane and a bipolar membrane, and at least one second membrane is selected from a group comprising a monoselective anion exchange membrane, a monoselective cation exchange membrane and a proton-selective exchange membrane, with the proviso that the membranes are respectively selected independently of each other and that at least one first membrane in the membrane electrolysis stack is a bipolar membrane.

Abstract: In regenerating an electroless metal plating bath by electrodialysis, it has been found that the metal of the metal plating bath deposits in the electrolysis arrangement. To overcome this problem, an improvement to prior art regenerating devices is suggested, said improvement consisting in providing main cation exchangers for removing ions of this metal from a concentrate fluid. The main cation exchangers are coupled to the concentrate compartments of the electrolysis arrangement in such a manner that the concentrate fluid flowing through the concentrate compartments is allowed to pass through the main cation exchangers and to be recirculated back into the concentrate compartments.

Abstract: The invention provides a process for depositing metallic layers from acidic or alkaline zinc or zinc alloy baths containing organic additives selected from brighteners, surfactants and complexing agents, a soluble zinc salt and optionally further metal salts selected from Fe, Ni, Co, Sn salts, wherein the bath can be purified continuously so that the process can be operated without interruption, as well as apparatus for carrying out this process.

Abstract: In regenerating an electroless metal plating bath by electrodialysis, it has been found that the metal of the metal plating bath deposits in the electrolysis arrangement. To overcome this problem, an improvement to prior art regenerating devices is suggested, said improvement consisting in providing main cation exchangers for removing ions of this metal from a concentrate fluid. The main cation exchangers are coup0led to the concentrate compartments of the electrolysis arrangement in such a manner that the concentrate fluid flowing through the concentrate compartments is allowed to pass through the main cation exchangers and to be recirculated back into the concentrate compartments.

Abstract: A method and a device for the regeneration of an electroless metal deposition bath containing hypophosphite ions by electrodialysis is described. The method according to the invention and the device differ from the prior art in that the bath solution is led simultaneously through diluate compartments in a second electrodialysis unit having cathodes and anodes, which compartments are separated from concentrate compartments in the second electrodialysis unit on the cathode side by monoselective anion-exchange membranes and on the anode side by anion-exchange membranes, the diluate compartments and the concentrate compartments in the second electrodialysis unit being disposed alternately to one another.

Abstract: The continuous process for making a metal structured foil, especially a flat conductor line, a flexible circuit board and a heating foil, by chemically and electrochemically metallizing a nonconductor foil, comprises the steps of:a. chemically metallizing both sides of the nonconductor foil to form a metal layer on both sides,b. coating an activated surface which is not to be metallized,c. electrolytically removing the metal layer on edge regions of the rear side of the foil and from a plurality of surfaces not to be reinforced electrochemically on the front side(operating side) or on both sides, andd. cathodically polarizing the front side(operating side) of the foil by a current-carrying roller and simultaneously performing an electrochemical bath metallization, whereby chemical dissolution of the metal layers on the rear side and electrochemical reinforcement of the chemically metallized surfaces on a free portion of the front side(operating side) or both sides occurs.