Persulfate activation by Fe(III) with bioelectricity at acidic and near-neutral pH regimes: Homogeneous versus heterogeneous mechanism.

•Efficient degradation of BPA in MFC/Fe(III)/PDS system achieved at pH 2.5 and 6.0.•Homogeneous activation at pH 2.5 with main reactive species of SO4•− in the solution.•Heterogeneous activation at pH 6.0 with dominant reactive species of adsorbed SO4•−.•The precipitate formed at pH 6.0 determined as amorphous iron oxyhydroxides.