Harnessing singlet oxygen for advanced electrochemical treatment of coking wastewater
Yun Guo, Rui Wang, Lehui Ren, Yang Li, Xueye Wang, Yi Jiang, Li Wang, Zhiwei Wang
Abstract
Refractory organic compounds (ROCs) in high salinity coking wastewater present a significant challenge to effective treatment. In this study, we employ a Pd-loaded porous titanium anode in an electrochemical advanced oxidation process (EAOP) to degrade ROCs with singlet oxygen ( 1 O 2 ) as the primary reactive species. At 5 mA/cm 2 , the Pd/PdO x /Ti system achieved a 92.3 % ROCs removal within 4 hours and maintained excellent stability over multiple cycles. Analytical analyses indicate the breakdown of complex organics into small molecules. Electron paramagnetic resonance (EPR) spectroscopy identified that 1 O 2 as the dominant reactive species. Thus, this process suppresses the generation of chlorinated by-products, highlighting its suitability in treating real-world high-salinity wastewater. In addition, the Pd/PdO x /Ti anode exhibited lower energy consumption (61 ± 2.3 kWh/kg) and higher current efficiency (23.2 %), compared to the commercial Ir/Ta and BDD electrodes, underscoring its potential as an energy-efficient and reliable solution for coking wastewater treatment.