In this study

an ionic liquid (IL)

1-butyl-2

3-dimmmethylimidazolium hexafluorophosphate ([Bmmim

]

[PF

6

]

)

was used in combination with a composite solvent of methyl acetate and

n

-heptane to enhance the oil extraction from oily sludge. The oil recovery increased by approximately 15% compared with that of solvent extraction without [Bmmim

]

[PF

6

]

at the optimal ratios of IL to sludge and solvents to sludge

which were at 2:5 (M/M) and 4:1 (V/M)

respectively. The saturate

aromatic

resin and asphaltene (SARA) analysis revealed that the recovery of resins and asphaltenes was increased by 14% and 38%

respectively

in the solvent extraction with the addition of [Bmmim

]

[PF

6

]

. [Bmmim

]

[PF

6

]

maintained a good performance after its reuse four times. The addition of [Bmmim

]

[PF

6

]

changed the adhesion forces between oil and soil. The IL-assisted solvent extraction procedure followed the pseudo second-order kinetic model

while the unassisted solvent extraction procedure followed the pseudo first-order kinetic model. The results also demonstrated that [Bmmim

]

[PF

6

]

decreased the solvent consumption by approximately 60% each time.

Additionally

[Bmmim

]

[PF

6

]

can be easily separated. The results suggested that enhancing the solvent extraction with this IL is a promising way to recover oil from oily sludge with a higher oil recovery rate and lower organic solvent consumption than those with the unassisted solvent extraction method.