Electrochemical Techniques for the Extraction of Heavy Metals in Industry: Concepts, Apparatus And Costs

Summary Many technical processes result in the emission of heavy metals, and the reduction and elimination of these emissions make considerable demands on industrial purification plants. The precipitation of these toxic metals in a conventional purification plant, which begins in the mechanical purification process and continues during the biological stage, does not offer a satisfactory solution since the problem is merely deferred. The heavy metals subsequently pollute the sedimentation sludge or its ash, as the case may be, making further treatment necessary at this stage. The logical conclusion is that such polluted water should be treated at its source with a special preliminary purification. Electrochemistry, which is one of the oldest methods in chemical technology, offers a very interesting possibility for solving this problem. It is known that metals can be separated out of their solutions selectively using electrochemical processes. The question here is whether this technique can be applied to the industrial purification methods to justify a decision in favor of these methods. It is definitely essential to first make a careful selection of the most suitable process concepts for providing effluent purification at a reasonable cost when such large technical purification plants are being planned and constructed.