The generation of reactive oxygen species generally requires initiators in various environmental remediation processes, which necessitates high dosage of activators and downstream treatment for eliminating the accumulation of deactivated catalysts. Herein, a coupled process was constructed using trace iron for simultaneously activating HSO₃⁻/O₂ system and peroxydisulfate (PDS) oxidation system, where the iron ions (2 mg/L) transferred single-electron from the former system to the latter due to the moderate redox potential (Fe³⁺/Fe²⁺, +0.77 V) between the potentials of SO₃^·−/HSO₃⁻ (+0.63 V) and PDS/SO₄^·− (+2.01 V). Hence, the phenol degradation quickly occurred at a first-order kinetic constant of k₁=0.223 min⁻¹ due to the accelerated generation of sulfate radical (SO₄^·−) and hydroxyl radical (^·OH) in the process. The k₁ value was almost 6-fold of that in the deoxygenated condition (0.040 min⁻¹). Density function theory reveals that the single electron shuttle spatially separates the electron-donating activation of HSO₃⁻ and electron-accepting activation of PDS, while avoiding the “mutual-annihilation” of HSO₃⁻ and S₂O₈²⁻ via direct two-electron transfer. Finally, utilizing the in-situ generated electron-shuttle (dissolved iron from cast iron pipe), the HSO₃⁻/PDS reagent could efficiently inactivate the chlorine-resistant pathogens and inhibits biofilm regrowth inside the distribution systems at regular intervals or infectious disease outbreak in a neighborhood.

活性氧的产生通常需要在各种环境修复过程中使用引发剂，这需要高剂量的活化剂和下游处理以消除失活催化剂的积累。在此，使用微量铁构建了一个耦合过程，用于同时激活 HSO ₃ ^- /O ₂系统和过氧二硫酸盐 (PDS) 氧化系统，其中铁离子 (2 mg/L) 将单电子从前者系统转移到后者，因为到SO ₃ ^·- /HSO ₃ ^- (+0.63 V) 和 PDS/SO ₄ ^·-电位之间的中等氧化还原电位 (Fe ³⁺ /Fe ^{2+ , +0.77 V)}(+2.01 V)。_{因此，由于硫酸根(SO 4} ^·- )和羟基自由基( ^· OH)的加速生成，苯酚的降解在k ₁ =0.223 min ^-1的一级动力学常数下迅速发生。k ₁值几乎是脱氧条件下(0.040 min ^-1 )的6倍。密度泛函理论揭示了单电子穿梭在空间上将HSO 3 - 的供电子激活和PDS的受电子激活分开_，^同时避免了HSO ₃ ^-和S ₂ O _{8的“相互湮灭”。}²⁻通过直接的双电子转移。最后，利用原位产生的电子穿梭（铸铁管中的溶解铁），HSO ₃ ^- /PDS 试剂可以有效地灭活耐氯病原体，并在分配系统内定期或传染病爆发时抑制生物膜再生在一个街区。