Abstract
The iron and manganese oxide filter film (MeOx) were used to research the simultaneous removal of bisphenol A (BPA), manganese (Mn2+) and ammonium (NH4+) in a pilot-scale filter system. We found that 0.52 mg/L of BPA could be removed while consuming 5.44 mg/L of dissolved oxygen (DO). Since the oxidation process of NH4+ and BPA both consume the DO in water, the presence of NH4+ can hinder the removal of BPA. The presence of Mn2+ in water had a synergy effect on the BPA removal. The filter film was characterized by SEM, XRD and XPS. Some substances were generated to block the pores of the oxide film, and a small amount of film was found to crack and fall off. The elemental composition of C and O were both increased by about 9%, the composition of Mn was decreased from 63.48% to 44.55%, and the reduced manganese substance might affect the activity of the oxide film. The main chemical forms of MeOx are Mn6O12·3H2O, MnFe2O4 or Mn3O4. The decrease in the removal efficiency of BPA was mainly due to the C-containing intermediate [−CH2C − H(OH)]n covering the surface of the oxide film and blocking the pore size of the film.
Acceleration of oxidation process of iron in supercritical water containing dissolved oxygen by the formation of H2O2
