Different heterogeneous fenton reaction based on foam carrier loaded with photocatalysts

The effect of heterogeneous Fenton reaction was studied on methylene blue (MB) and Nitrosomonas europaea (N. europaea) cells. Four Fenton systems were prepared and compared with each other, including Nickel Foam (NF)/TiO₂, NF/Bi₂WO₆, Ceramic foam (CM)/TiO₂, and CM/Bi₂WO₆. The order of effect of fenton reaction ranked as NF/TiO₂>CM/TiO₂>NF/Bi₂WO₆>CM/Bi₂WO₆. In acid or alkaline solution, the removal efficiency also decreased compared with neutral solution. With lower pH values, the nanoparticles were easier to break off from NF skeleton. Thus the synergetic effect of photocatalysis and fenton reaction can not take action. As for CM skeleton, the bond–Si-O-can bind with TiO₂ or Bi₂WO₆. The membrane fluidity was used as an indicating parameter. After being treated by Fenton reaction, N. europaea surface was rougher than the native bacterium and the bulges on cell surface became irregular, which is attributed to change of lipopolysaccharide patches. Polarization of N. europaea cell membrane in acid medium increased more obvious than alkaline medium.