There are many factors affecting the flocculation and sedimentation of fine sediments. The objective of this study was to explore the effect of potassium sulfate fertilizer on the sedimentation of the static Yellow River water. Taking potassium sulfate concentration and sediment particle size as parameters

five potassium sulfate concentrations and four particle size ranges (<100

50~100

34~50

and <34 μm) of Yellow River sediment were studied by pipette method. In the sedimentation process

the effects of different potassium sulfate concentrations on the flocculation of fine sediments were discussed. The results showed that the higher the concentrations of potassium sulfate were

the faster the sediment concentration decreased

the higher the sedimentation velocity was. The initial particle size was <100 μm

and when the concentrations of potassium sulfate were 0

2.86

7

14 mmol/L

the sedimentation time was 30 min

the relative sediment concentrations were 35.35%

30.75%

27.02%

14.00%

and the median sedimentation speed ω50 was 1.55

3.00

3.91 and 4.93 cm/min

respectively. The smaller the initial sediment particle size was

the more obvious the promotion effect of potassium sulfate on flocculation sedimentation was. The sediment of <34 μm sediment was most affected by potassium sulfate. When the potassium sulfate concentration increased from 0 to 60 mmol/L

the median sedimentation velocity after flocculation with initial particle size <34 μm increased from 1.38 cm/min to 8.53 cm/min

increased by 518.12%

and the median sedimentation velocity after flocculation with initial particle size of 34~50 μm increased from 6.29 cm/min to 8.43 cm/min

with an increase of 34.02%. The median sedimentation velocity of sediment from 50 to 100 μm increased from 7.12 cm/min to 7.59 cm/min

with an increase of 6.60%.The smaller particle size of sediment and the greater concentration of potassium sulfate gave the greater influence on the median particle size after flocculation. When the concentrations of potassium sulfate increased from 0 to 60 mmol/L

there was no obvious rule between the concentrations of potassium sulfate and the median particle size after flocculation of sediment with initial particle size of 50~100 μm. There was no significant difference between different treatments. Potassium sulfate had no effect on the flocculation settling of sediment with this particle size. After flocculation

the median size of sediment with initial particle size of 34~50 μm increased from 38.8 μm to 41.0 μm

increasing by 5.76%. After flocculation

the median size of sediment with initial particle size <34 micron increased from 15.7 μm to 21.6 μm

increasing by 37.82%. After flocculation

the relative contents of small and medium-sized particles decreased

the relative contents of large-sized particles increased

and the maximum particle size increased. When the particle size of sediment was <34 μm

the concentration of potassium sulfate was 60 mmol/L

and the maximum particle size after flocculation was 200 μm.