Nano spinel CoFe2O4 deposited diatomite catalytic separation membrane for efficiently cleaning wastewater

To enhance the cleaning efficiency of the ultrafiltration membrane for wastewater, nano spinel CoFe 2 O 4 was synthesized on diatomite via hydrothermal reaction strategy to prepare nano spinel CoFe 2 O 4 deposited diatomite (CF/Dt) particles for activating peroxymonosulfate (PMS), and then used as a functional layer to form CF/Dtcatalytic separation membrane (CF/Dt-M) to remove small and medium molecular pollutants by precise separation and catalytical oxidation . CF/Dt particles and CF/Dt-M were characterized by SEM. The CF/Dt-M was used to deeply clean simulated wastewater containing oil and rhodamine B for investigating its separation and catalytic oxidation performances. The results show that nano spinel CoFe 2 O 4 particles with diameter of 20–100 nm are deposited on the surface of diatomite, and the thickness of CF/Dt-M functional layer is 44 μm. After cleaning simulated wastewater using CF/Dt-M, concentration of oil, RhB and COD in permeate reduces from 57 mg L −1 , 20 mg L −1 , 231 mg·L −1 to 8 mg·L −1 , 0 mg L −1 and 47 mg L −1 , respectively. Water yield of CF/Dt-M is 658 L m −2  h −1 under 0.06 MPa. Nano spinel CoFe 2 O 4 in CF/Dt-M can efficiently activate a small amount of PMS to release a lot of SO 4 •- , making CF/Dt-M perform properties of precise separation and catalytic oxidation. Therefore, CF/Dt-M is a promising candidate extensively applied for cleaning wastewater.