Magnetic enhanced coagulation membrane filtration (MECMF) process was introduced into micro-polluted surface water treatment. The process was conducted by adding magnetic powder (MP) for enhancing coagulation. By contrasting the water quality parameters including DOC, UV254 and turbidity of permeates of MECMF and coagulation/flocculation membrane filtration (CFMF), results showed that the removal efficiency in MECMF process was higher than those in CFMF process. According to normalized flux and resistance analysis, membrane flux declined relatively slow and irreversible fouling resistance was lesser in MECMF process. By analyzing the three-dimensional fluorescence of permeates and raw water, it was clearly shown that the permeate quality of MECMF process was superior to that of CFMF process apparently which highlighted the removal of protein-like substances was more effectively in MECMF. Furthermore, the addition of MP could provide Lorentz force and magnetic dipole force between colloidal matters during coagulation, leading to the increase of collision frequency and efficiency and the formation of large size flocs with high fractal dimension. Large and high fractal dimension flocs could form porous cake layer which could increase water permeability. On the basic of above findings, it was suggested that magnetic enhanced coagulation which promoted flocs to develop could regulate cake layer structure and mitigate membrane fouling to some extent.
- micro-polluted water
- magnetic enhance coagulation membrane filtration (MECMF)
- magnetic powder (MP)
- fouling mitigation
- First received 21 May 2015.
- Accepted in revised form 10 July 2015.
- © IWA Publishing 2015