Defluoridation characteristics of a novel adsorbent developed from ferroalloy electric arc furnace slag: Batch, column study and treatment of industrial wastewater

Abstract The contamination of fluoride ions in ground and industrial wastewater is a serious concern for a long time. For this purpose, a novel adsorbent was prepared from ferroalloy electric arc furnace (FEAF) slag, a waste material of steel industry. It is a source of multiple oxides which can serve the purpose of defluoridation. Its adsorptive property was augmented by heat and acid activation. The synthesized adsorbent was characterized by various analytical methods for the affirmation of successful activation of slag and formation of spent adsorbent. The experimental investigation of isotherm and kinetic study demonstrated the better fitting into Langmuir isotherm and pseudo second order kinetic model, respectively. The Q max of prepared adsorbent was 13.43 mg/g at 45 °C. The endothermic and spontaneous behaviour of fluoride adsorption was revealed by the thermodynamic study. The application of activated FEAF slag adsorbent in batch and column exhibited significant improved and enhanced performance of 68.98%–97.42% defluoridation and 24–54 bed volumes treatment, respectively. The activated slag adsorbent was potential for defluoridation of industrial wastewater. Hence, it served two purpose at a time (i.e., reuse of industrial waste material and treatment of wastewater), which is a unique feature of the prepared adsorbent.