Removal of nickel from industrial process liquids

In general, during the last two decades much research has been devoted to the protection of the environment. For instance, waste discharges into waters and disposal of solids to land sites have to be minimised. Environmental electrochemistry can make a huge contribution to reach this goal. Moreover, there is a tendency in the metal finishing and metal processing industries to redesign processes as closed loop systems. Therefore, we especially think the purification of dilute heavy-metal-ion containing process liquids needs much of our attention. A critical evaluation of the usefulness of different types of electrodes is given, because of their central importance in electrochemical processes and in electrochemical cell design. One of the most challenging metals is nickel, because it is one of the more precious metals and it is used in galvanic industry. This is why the focus in this paper is on the removal of nickel, though conclusions are not necessarily restricted to the removal of this metal.