Staged and efficient removal of tetracycline and Cu2+ combined pollution: A designed double-chamber electrochemistry system using 3D rGO

In this study, a staged and efficient advanced treatment process for combined antibiotics and heavy ion pollution based on a designed electrochemical double-chamber system using three-dimensional reduced graphene as the electrode material was established. Tetracycline (TC) and copper ions as the common pollutants in the tailwater of livestock wastewater were chosen as representative antibiotics and heavy ions. A high removal efficiency of almost 100% of tetracycline and copper ions at low concentrations (10 mg/L) was obtained using the electrochemical double-chamber system. Under the optimal reaction conditions, the estimated energy consumption was 0.25 KWhm−3. Among the 20 mg/L and 50 mg/L composite pollutants, the removal efficiencies of tetracycline were 92% and 82%, respectively, and the removal efficiencies of copper ions were 99% and 100%, respectively. In the treatment of actual tailwater from livestock wastewater, the removal efficiencies of copper ions and total organic carbon (TOC) were 89% and 63%, respectively. In the same treatment time, compared to a single-chamber reaction system, the TC removal efficiencies increased by 13%, 20%, and 26%, and the removal efficiencies of Cu2+ increased by 28%, 48%, and 41% in the treatment of 10 mg/L, 20 mg/L, and 50 mg/L composite pollutants, respectively. In addition, the staged disposal method based on the electrochemical double-chamber system had a higher efficiency and double the treatment capacity for removing combined tetracycline and copper ion pollution than a general electrochemistry system in an equal time period. This study offers a practical and efficient treatment system for combined pollution in water.