ELECTROKINETIC REMEDIATION OF SOILS POLLUTED WITH HEAVY-METALS - REMOVAL OF ZINC AND COPPER USING A NEW CONCEPT

A new concept has been developed for electrokinetic remediation of soils polluted with heavy metals. In the new concept two strong ion exchange membranes are used to separate the soil from the electrode chambers. This construction ensures high effectivity of the current with respect to removal of charged species - i.e. heavy metal ions - from the soil. To obtain proper electrode functions slightly acidic electrolytes are circulated through the electrode chambers. The concept has been tested on a laboratory scale equipment on a soil polluted with several heavy metals, and results with respect to removal of zinc and copper are shown and discussed. The influence of calcium, magnesium and iron ions simultaneously present in the soil is illustrated. Four different experiments were carried out where pH of the electrolytes in the electrode chambers were varied in steps from 1.6 to 2.2.