Method for decontaminating a liquid effluent containing one or more radioactive chemical elements by a fluidised bed treatment

The invention relates to a method for decontaminating a liquid effluent containing one or more radioactive chemical elements to be removed, said method including the following steps: a step of contacting said liquid effluent, in an agitated fluidised bed in a first area of a reactor, with solid particles capable of trapping and retaining one or more radioactive chemical elements by co-precipitation and/or adsorption and/or ion exchange, whereby a suspension of solid particles containing one or more radioactive chemical element(s) is obtained; a step of decanting said suspension in a second area of the same reactor, said second area being separate from the first abovementioned area, whereby a solid phase including the solid particles containing said radioactive chemical element(s) to be removed and a liquid phase that is lean in or free of the one or more radioactive chemical element(s) to be removed are obtained; and a step of separating said solid phase from said liquid phase.