The work described here concerns the electrochemical coagulation of effluents obtained in a surfactant-aided soil-remediation processes, in which phenanthrene was extracted from a clay soil using a sodium dodecyl sulphate solution as the solubilising fluid. The results show that the efficiency of the processes is largely influenced by the electrode materials employed in the electrocoagulation process and also by the initial pH of the treated effluents. Different cases have been studied, including synthetic effluents from soil-washing and electrokinetic soil-flushing. This technique is particularly effective in the treatment of the strongly acidic effluents arising from electrokinetic surfactant-aided soil-flushing of polluted soils using aluminium electrodes (anodes and cathodes). Under these conditions, in addition to a high level of pollution removal, this technology provides a significant reduction in the conductivity and partial neutralisation of the effluent. (c) 2012 Elsevier B.V. All rights reserved.