Energy generation and abatement of Acid Orange 7 in reverse electrodialysis cells using salinity gradients

The simultaneous generation of electric energy and the treatment of wastewaters contaminated by an organic pollutant resistant to conventional biological processes, Acid Orange 7 (AO7), was achieved for the first time using proper redox processes by reverse electrodialysis using salinity gradients. The stack was fed with two aqueous solutions with different concentrations of NaCl and a synthetic wastewater contaminated by AO7. Various electrochemical approaches including electro-Fenton, electrogeneration of active chlorine (IOAC) and coupled process were performed in a stack equipped with 40-60 cell pairs and studied by focused electrolyses. The effect of the number of cell pairs and of the NaCl concentration of saline solutions was also investigated.