Feasibility of UVC-LED/H2O2 advanced oxidation processes as a hybrid water treatment system uniting secondary battery and microbial fuel cell

An innovative hybrid water treatment system consisting of an ultraviolet C light-emitting diode sequentially connected to a secondary battery and microbial fuel cells was developed and systematically optimized via an electrochemical performance test. According to standardized bio-dosimetry, the generated ultraviolet intensity powered by a pre-charged battery was determined to be 2.3×10 −1 μW cm −2 . The quantified UV intensity was used in calculating the fundamental kinetic parameters for the inactivation of microbial entities and the degradation of organic pollutants during UVC-LED and UVC-LED/H 2 O 2 treatment processes. The fluence-based first-order rate constants were 1.07 and 2.43 cm 2 /mJ for Escherichia coli and 0.10 and 0.18 cm 2 /mJ for MS-2 bacteriophage, respectively. The study detected 2.76–8.00×10 −16 M hydroxyl radicals at steady-state during UVC-LED/H 2 O 2 treatment with 0.3–1 mM H 2 O 2 . The second-order rate constant for atrazine during UVC-LED/H 2 O 2 treatment was 1.90×10 9 M −1 s −1 according to linear regression analysis of atrazine elimination over •OH exposure. This comprehensive investigation expands the application of microbial electrochemical systems in water treatment, providing a fundamental kinetic dataset for quantifying and predicting the microbial and (persistent) organic pollutants abatement. • A hybrid system of UVC-LED/SB/PMS/MFC was elaborately developed. • The system was optimized following electrochemical parameter profiling. • UVC-LED, activated by pre-charged SB, was applied to water treatment. • The intensity of UVC-LED was enhanced by 10-times compared to the prior system. • Selected microbial and organic pollutants were effectively abated by UVC-LED or UVC-LED/H 2 O 2 .