HF wastewater remediation by electrocoagulation process

Simultaneous removal of chromium(VI) and fluoride by electrocoagulation–electroflotation: Application of a hybrid Fe-Al anode

“…This is likely due to the higher affinity of aluminum coagulants comparing with iron ones towards fluoride [9,39].…”

“…Studies confirm that the relative performance of the anode material is variable and depends on the nature of target pollutant to be removed [19]. By using aluminium as anodes, many researchers found that EC is efficient as polishing treatment for fluoride removal after lime precipitation [1,9,10,20,21], while iron anodes gave less sufficient fluoride removal efficiency [9]. Similarly, EC is very common for chromium(VI) removal [12,22,23].…”

“…However, Mouedhen et al [23] found that, unlike iron, aluminum electrodes were found to be unsatisfactory for Cr(VI) removal. Typical EC treatment of wastewater containing both Cr(VI) and fluoride implies a sequence of an EC-Al for fluoride removal followed by pH adjustment for lowering pH, due to inherent EC pH rise [9,11], then an EC-Fe step to eliminate Cr(VI).…”

“…Electrocoagulation (EC) has been successfully proposed as an alternative method to classic chemical coagulation for many wastewater treatments [1,[9][10][11]. EC consists of in situ electrogeneration of coagulants Al(III) or Fe (II) by means of electrodissolution of aluminum and iron anodes respectively [12].…”

“…Although the treatment of fluoride and chromium separately by EC was extensively studied [1,[9][10][11][12][20][21][22][23], no study had explored simultaneous removal of Cr(VI) and fluoride by EC using Al, Fe or hybrid Fe-Al anode. Furthermore, most previous studies dealing with hybrid electrode used either aluminium or iron as cathode.…”