Characterization of Electrocoagulation for Removal of Chromium and Arsenic

Protection of the global environment and, in particular, providing a sustainable source of clean water is a necessity for human survival. The wide use of heavy metals by modern industries has generated by‐products containing heavy metals. Specifically, large quantities of chromium and arsenic containing compounds are being discharged into the environment. This study has been conducted to determine the feasibility of an electrocoagulation (EC) process using air injection to remove these inorganic elements with iron electrodes. Powder X‐ray diffraction, scanning electron microscopy, and transmission Mössbauer spectroscopy were used to characterize the solid products formed at iron electrodes during EC. The results of this study suggest that magnetite particles and amorphous iron oxyhydroxides are present in the examined EC products. The field pilot‐scale study demonstrated the removal of Cr(VI)/Cr(III) and As(III)/As(V) with an efficiency of more than 99 % from both wastewater and wells. Chromium and arsenic containing compounds are generated by various industries and are often discharged into the environment. In particular, chromium and arsenic contaminated natural waters are a considerable problem. Electrocoagulation with air injection is a promising alternative technique for the removal of these toxic metals from wastewater and has the potential to eliminate the drawbacks of classical treatment techniques, as it does not require chemical additions generating secondary pollutants.