Analysis of polarization processes at electrokinetic remediation of clay soils and evaluation of the contribution of various components into the transport of charged contaminants are performed. The peculiarities of soil decontamination at constant and pulse voltages are investigated using kaolinite and mixture of montmorillonite and sand contaminated with radionuclides (¹³⁷Cs, ⁹⁰Sr, U) and heavy metals (Co) as model systems. It is shown that the use of unipolar pulse voltage changes the distribution of contaminations in soil and allows to decrease power inputs. It is also demonstrated that the introduction of cation-exchangers CU-2-8 into electrode chambers considerably improves the degree of soil decontamination. The most effective method to intensify the decontamination of clay soils from radionuclides and heavy metals is the wetting of soil with enhancement reagents (acetic, nitrilotriacetic and ethylenediaminetetraacetic acid).