Evaluation of electrocoagulation process for the removal of strontium and cesium from aqueous solution

•Removal of radioactive contaminants was investigated by electrocoagulation.•Experimental analysis showed electrocoagulation was highly efficient process for the removal of Sr and Cs.•Adsorption equilibrium follows pseudo-second-order model.•Equilibrium data were well described by the typical Langmuir adsorption isotherm.•Thermodynamic studies revealed that the adsorption reaction was spontaneous and endothermic process. The present research work deals with an evaluation of electrocoagulation process for the removal of radioactive contaminants like strontium and cesium from water using different anode materials like aluminum, iron, magnesium, and zinc with galvanized iron as cathode. The optimization of various operating parameters like effect of pH, current density, temperature, and inter-electrode distance on the removal efficiency of strontium and cesium were carried out. The results showed that the maximum removal efficiency of 97.0% and 96.8% was achieved for strontium and cesium respectively with magnesium as anode at a current density of 0.08A/dm2 and pH of 7.0. First and second-order rate equations were applied to study adsorption kinetics. The adsorption process follows second order kinetics model with good correlation. Langmuir and Freundlich adsorption isotherm model were studied using experimental data. The Langmuir adsorption isotherm favors monolayer coverage of adsorbed molecules for adsorption of strontium and cesium. Temperature studies showed that adsorption was endothermic and spontaneous in nature.