Removal mechanism by magnetic components
With the magnetic field, NO3--N
removal was 71.3%, while without magnetic field,
NO3--N removal was 58.1% (Figure 8a).
The mechanism of enhancing NO3--N
removal under magnetic field was explored using MATLAB. When the
distance between magnetic particles was constant, the greater the
applied magnetic field intensity, the greater the interaction potential.
Furthermore, the interaction potential between magnetic particles with
magnetic field was five orders of magnitude higher than that without
magnetic field (Figure 8b). Without magnetic field, the particle
interactions are only vdW and electrostatic . With the applied magnetic
field, an additional magnetic interaction is generated among magnetic
particles34, which increases the total interaction
potential. According to the collision efficiency formula and the
classical flocculation model (SI), the higher the interaction potential,
the higher the interparticle collision efficiency \(\alpha_{\text{ij}}\)and the coagulation efficiency.35 Therefore, the
applied magnetic field can increase the interaction potential between
particles, thereby enhancing the contaminant removal when using MHC.