Selective pollutant degradation with a novel persulfate activation cell resistant to environmental interference

Abstract

The activation of persulfate by heterogeneous catalysts is susceptible to background matrices present in wastewater, resulting in reduced catalytic efficiency during practical applications. Herein, a persulfate activation cell (PAC) is developed by spatially separating pollutants and persulfate into two independent chambers. The CuCoNi-NF catalyst is fabricated and utilized as the electrode of the PAC. The performance of the PAC is compared with a mixed persulfate activation system (PAM) concerning cyclic degradation of various phenolic pollutants and in the presence of different environmental matrices. The results indicate that phenol pollutants such as bisphenol A (BPA) can be degraded in the PAC via transferring electrons to persulfate. The PAC exhibits superior stability compared to the PAM during six cyclic BPA degradation experiments, with BPA degradation rate constant decreasing by 16.7% for PAC and 81.9% for PAM. Over the 192-hour continuous operation period, the PAC attains a BPA removal efficiency of 88.8 ± 5.6%, a TOC removal efficiency of 74.0 ± 4.6%., and a current output of 0.24 ± 0.04 mA. Furthermore, environmental matrices such as cations, anions, humic acid, and natural water environments demonstrate a slight enhancing effect on BPA degradation in the PAC while conversely displaying inhibition in the PAM. High solution conductivity benefits BPA degradation in the PAC by reducing internal resistance. The pH level of the environment (pH 6–9) has minimal impact on the degradation of BPA in the PAC. The pollutants begin to degrade in PAC when the anode potential reaches their oxidation potential, and the stable potential difference between the anode and cathode ensures the continuous oxidation of the pollutants. Our work proposes a novel persulfate activation strategy that can effectively degrade target pollutants by resisting environmental interferences.