Effect of controlled temperature and biomass addition on the formed environmental persistent free radicals (EPFRs) in sewage sludge-based biochar from pyrolysis treatment

Insight into biomass feedstock on formation of biochar-bound environmentally persistent free radicals under different pyrolysis temperatures

“…Overall, concentrations and types of EPFRs in sludge-based biochars differed greatly from those in the lignocellulosic-biomass-based biochars. This was consistent with the previous report that the spin concentration of EPFRs in sludge-based biochar ranged from 2.16 Â 10 16 to 4.42 Â 10 16 spins per g in the pyrolysis temperature of 200 to 600 C. 44 In some papers, the g-factor of PFRs in sludge-based pyro-biochars were reported while their spin concentration were not offered, [25][26][27] which cannot be compared with our results. The spin concentration were generally 10 18 -10 19 spins per g for the lignocellulosic-biomassbased biochars, consistent with our results.…”

Role of Electronegativity in Environmentally Persistent Free Radicals (EPFRs) Formation on ZnO

“…The radicals thus formed can produce either oxygen-centered or carbon-centered EPFRs (see Figure ). , EPFRs are resonance-stabilized radicals, and therefore resist degradation, and persist in ambient environment . EPFRs have much longer half-lives than most typical free radicals and can persist for hours, weeks, or months .…”