A process for decontaminating a medium polluted with metals and hydrophobic organic compounds (HOC) includes providing an acidic slurry of water, acid, chloride salt, surfactant, and the polluted medium. Flotation is preformed on the acidic slurry to form a HOC-rich froth and an HOC-depleted slurry and the froth is recovered. The slurry is separated to obtain a treated solid and a liquid effluent rich in metallic ions. Preferably, the process also includes recuperating the metals by chemical precipitation and/or electrodeposition to produce a treated solution. Also provided are a decontaminant having an acid, a chloride salt, and a surfactant as well as a chemical kit for decontaminating the polluted medium including the decontaminant in which the acid, chloride salt and surfactant can be mixed with polluted medium in the presence of water before removing at least a portion of the metals and HOC from the polluted medium.