Experimental investigation on the removal of phenol from simulated wastewater by reverse electrodialysis reactor

The removal of phenol from simulated wastewater by a reverse electrodialysis reactor (REDR) wastewater treatment system is experimentally investigated in independent or synergetic degradation circulation mode under specific conditions. Results demonstrated that the total degradation efficiencies (eta(de,tot)) and the total chemical oxygen demand (COD) removal efficiencies (eta(COD,tot)) in an independent degradative circulation mode were better than those in a synergetic degradative circulation mode. After 2 h of treatment, the eta(de,tot) of phenol reached 100% and 99.7%, and eta(COD,tot) reached 59.6% and 51.3%, under two circulation modes, respectively. However, the synergistic degradation cycle mode achieved a balance between hydrogen ion production and consumption during the wastewater treatment process. When the synergetic circulation mode was applied, the pH of the wastewater was always maintained at around 3 without the addition of acid, which reduced the wastewater treatment costs. Moreover, the general current efficiency and the energy consumption of REDR in the synergetic degradative circulation mode were 51.1% and 168.8 kWh/kgCOD, respectively, after 2 h. Therefore, the implementation of REDR with a suitable circulation mode and operating conditions offered a viable alternative to achieve a win-win situation for both energy and the environment.