Fluoride removal from industrial effluents by combining precipitation and electrocoagulation processes

Abstract

The aim of this study was the removal of fluoride from a fluoride-rich industrial wastewater by combining two processes, precipitation with a magnesium salt and electrocoagulation. The sacrificial anode was made of Al and the applied current densities were of 100, 200 and 300 A/m2, respectively. The experiments were conducted at pH of 5.2, 6.2 and 7.2, respectively, and the electrolysis time was of 15, 30, 45 and 60 min, respectively. 0.01 M NaCl was supporting electrolyte. The best results were obtained at pH of 6.2, 200 A/m2 and 45 minutes of electrolysis when the specific energy consumption was of 5.6 kWh/m3.