posted on 2021-09-24, 18:04authored byYanchen Sun, Jeongdae Im, Nusrat Shobnam, Sofia K. Fanourakis, Lilin He, Lawrence M. Anovitz, Paul R. Erickson, Huihui Sun, Jie Zhuang, Frank E. Löffler
Bisphenol A (BPA), a high production
volume chemical and potential
endocrine disruptor, is found to be associated with sediments and
soils due to its hydrophobicity (log KOW of 3.42). We used superfine powdered activated carbon (SPAC) with
a particle size of 1.38 ± 0.03 μm as a BPA sorbent and
assessed degradation of BPA by oxidized manganese (Mn) species. SPAC
strongly sorbed BPA, and desorption required organic solvents. No
degradation of adsorbed BPA (278.7 ± 0.6 mg BPA g–1 SPAC) was observed with synthetic, solid α-MnO2 with a particle size of 15.41 ± 1.35 μm; however, 89%
mass reduction occurred following the addition of 0.5 mM soluble Mn(III).
Small-angle neutron scattering data suggested that both adsorption
and degradation of BPA occurred in SPAC pores. The findings demonstrate
that Mn(III) mediates oxidative transformation of dissolved and adsorbed
BPA, the latter observation challenging the paradigm that contaminant
desorption and diffusion out of pore structures are required steps
for degradation. Soluble Mn(III) is abundant near oxic-anoxic interfaces,
and the observation that adsorbed BPA is susceptible to degradation
has implications for predicting, and possibly managing, the fate and
longevity of BPA in environmental systems.