Reactive oxygen species formation in thiols solution mediated by pyrogenic carbon under aerobic conditions.

Previous studies have demonstrated that pyrogenic carbon can mediate the reductive degradation of pollutants in solutions containing reducing reagents under anaerobic conditions. However, few studies have investigated oxidative species formation and pollutants transformation directly mediated by pyrogenic carbon under aerobic conditions. In this study, we found that activated carbon (AC) can not only mediate reductive hexachloroethane degradation in the absence of O but also mediate the oxidation of As(III) and sulfanilamide in L-Cysteine (Cys, a naturally abundant thiol compound) solution under aerobic conditions. Electron paramagnetic resonance and quenching studies indicated that O, HO and OH was formed in Cys/AC system under aerobic conditions. High O content favored the formation of OH, indicating that O participated in OH production. In addition, an increase in AC concentration and specific surface area led to increased formation of OH, and other pyrogenic carbon materials such as biochar and graphite were also found capable of mediating the formation of OH. This study demonstrates that pyrogenic carbon could mediate OH formation in solutions containing reductive reagents under aerobic conditions, which provides a new perspective for studying the behavior of pyrogenic carbon in the environment and its role in biogeochemical processes.