*2.7. Zeta Potential Experiment*

After the settling experiment, the supernatant was taken out to test the zeta potential of the slurry after flocculation pretreatment. Zeta potential is often used to characterize the electrical characteristics of particles and can be used to reveal the degree to which particles are affected by conditioners. The zeta potential was measured through electrophoretic light scattering by using a Zetasizer Nano ZSP (Malvern Instruments, Malvern, UK). DTS1070 cell was used to perform the zeta potential test. The supernatant was injected into the cell, then the cell was pressed into the measurement chamber to test the zeta potential. Each test was performed thrice in parallel.
