A process for the treatment of a hydrocracking unit bottoms recycle stream containing heavy poly-nuclear aromatic (HPNA) compounds and HPNA precursors to reduce the content of HPNA compounds and precursors, the process comprising: a. contacting the bottoms recycle stream with an effective amount of adsorbent material in an adsorption vessel to produce an adsorbent-treated bottoms recycle stream having a reduced content of HPNA compounds and HPNA precursors; b. recovering and introducing the recovered adsorbent-treated bottoms recycle stream into an extraction unit with one or more ionic liquids for a predetermined time to extract the HPNA compounds and HPNA precursors and produce an extraction unit effluent stream and a treated stream; c. recovering and introducing the effluent stream from the extraction unit containing the mixture of the extracted HPNA compounds and HPNA precursors and the one or more ionic liquids into a separation unit for contact with an organic polar solvent; d. maintaining the mixture in the separation unit for a time that is sufficient to form a solution of the HPNA compounds and HPNA precursors in the polar solvent; e. recovering the one or more ionic liquids from the separation unit for re-use in the extraction unit; f. transferring the solvent containing the HPNA compounds and HPNA precursors to a solvent recovery unit and recovering a solvent stream for re-use in the separation unit; g. transferring from the extraction unit the remaining treated stream to a liquid-liquid separator and recovering as separate streams ( i) a treated hydrocarbon stream having a substantially reduced content of HPNA compounds, (ii) residual ionic liquids, and (iii) HPNA compounds and HPNA precursors. a. contacting the bottoms recycle stream with an effective amount of adsorbent material in an adsorption vessel to produce an adsorbent-treated bottoms recycle stream having a reduced content of HPNA compounds and HPNA precursors; b. recovering and introducing the recovered adsorbent-treated bottoms recycle stream into an extraction unit with one or more ionic liquids for a predetermined time to extract the HPNA compounds and HPNA precursors and produce an extraction unit effluent stream and a treated stream; c. recovering and introducing the effluent stream from the extraction unit containing the mixture of the extracted HPNA compounds and HPNA precursors and the one or more ionic liquids into a separation unit for contact with an organic polar solvent; d. maintaining the mixture in the separation unit for a time that is sufficient to form a solution of the HPNA compounds and HPNA precursors in the polar solvent; e. recovering the one or more ionic liquids from the separation unit for re-use in the extraction unit; f. transferring the solvent containing the HPNA compounds and HPNA precursors to a solvent recovery unit and recovering a solvent stream for re-use in the separation unit; g. transferring from the extraction unit the remaining treated stream to a liquid-liquid separator and recovering as separate streams ( i) a treated hydrocarbon stream having a substantially reduced content of HPNA compounds, (ii) residual ionic liquids, and (iii) HPNA compounds and HPNA precursors. ( i) a treated hydrocarbon stream having a substantially reduced content of HPNA compounds, (ii) residual ionic liquids, and (iii) HPNA compounds and HPNA precursors. <EOS>