The implications of biochar aging regarding their material properties as well as their interactions with
other contaminants are not vivid. We report the role of biochar aging on sorption behavior of di-alkyl
phthalates (PAEs). Biochars used in this study were produced from peanut-shell and their aging was
simulated by chemical oxidation. The structural composition and morphology of the obtained biochars,
before and after oxidation with HNO3/H2SO4, were analyzed by element composition, XPS, DRIFT, and
SEM/EDX. Several experimental results unequivocally showed oxygen enrichment in the mixed acid
treated samples compared to their precursors. Despite surface area reduction and pore destruction,
increased PAEs sorption on oxidized biochar surfaces portrayed existence of strong PAEs binding sites.
The adsorption of PAEs on oxidized biochar surface is a cumulative influence of hydrophobic interactions
and piepi electron donoreacceptor interactions. Our results suggest that imminent aging of biochar
upon environmental exposure may change their sorbent properties.