Degradation of Adsorbed Bisphenol A by Soluble Mn(III)

Abstract

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 K OW 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-MnO 2 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.

Alteration of birnessite reactivity in dynamic anoxic/oxic environments

“…On the other hand, previous works have reported that the Mn(III) oxides or Mn(III) complexes can rapidly oxidize a variety of organic compounds (Chen et al, 2013;Huang et al, 2018;Klewicki and Morgan, 1999;Nico and Zasoski, 2001). Mn(III) is a strong oxidant for one electron transfer reaction (Hu et al, 2017;Sun et al, 2021), compared to two electron transfer reaction involving Mn(IV).…”

Roles of MnO2 Colloids and Mn(III) during the Oxidation of Organic Contaminants by Permanganate

“…In contrast, Jiang et al ascribed the occurrence of the aforementioned autoaccelerating trend to the catalytic effect of the progressively accumulated MnO 2 colloids on the degradation of phenolic organics by Mn­(VII) under the acidic conditions. , Therefore, more efforts are urgently needed to clarify and quantify the role of MnO 2 colloids for gaining deeper insights into the underlying mechanisms of Mn­(VII) chemistry. Meanwhile, since Mn­(III) is reported to be reactive toward some organic contaminants, − its contribution in the Mn­(VII) oxidation process, which has been largely neglected in previous studies, also deserves investigation.…”

CNT encapsulated MnOx for an enhanced flow-through electro-Fenton process: the involvement of Mn(iv)

“…A previous study demonstrated that only soluble Mn( iii ) could oxidize BPA. 53 Thus, the possible soluble Mn( iii ) occurrence was examined in the MnO x -in-CNT system using UV-vis spectroscopy. As shown in Fig.…”