Non-radical activation of peracetic acid by Fe-Co sulfide modified activated carbon for the degradation of refractory organic matter

Abstract

Recently, the non radical activation system had attracted much attention due to its strong anti-interference ability. In this study, a novel FeCo₂S₄/activated carbon (AC) catalyst was prepared and used to construct a non radical dominated degradation system. Due to the electron-donating groups (C-OH) of AC and the conversion of free radicals generated from the activation of PAA by iron (Fe) and cobalt (Co) ions, a large amount of singlet oxygen (¹O₂) were produced, making the activation system possessed excellent universality and applicability for the removal of organic pollutants. Within 5 min, about 89.87 % of tetracycline hydrochloride (TCH) was removed in FeCo₂S₄ /AC + PAA. After only 20 min of reaction, the TCH removal efficiency reached 94.12 %, accompany with the reaction rate reached 0.099 min⁻¹. Other organic pollutants including ibuprofen (IBU), sulfamethoxazole (SMX), ciprofloxacin (CIP), p-nitrophenol (PNP) and atrazine (ATZ) were also efficiently removed within 20 min, with the removal efficiencies were 92.0 %, 91.5 %, 89.4 %, 88.3 %, and 84.5 %, respectively. When the solution pH changed from 5.01 to 9.48, FeCo₂S₄ /AC also showed excellent catalytic performances, with the TCH removal rates were maintained at over 85.18 %. Moreover, the removal rate of TCH still reached 90.23 % after 5 recycles. This study offered an efficient non-radical peracetic acid (PAA) activation system, which can be effectively used to degrade refractory organic pollutants from complex water environment.