Every tax lien or certificate for property offered at public sale, and not sold for want of bidders, unless it is released from sale by the withdrawal from collection of a special assessment levied thereon, shall be forfeited to the county, as trustee for the taxing districts, and managed pursuant to Section 21-90 . Tax certificates are also forfeited to the county in those circumstances described in subsection (d) of Section 21-310 and subsection (f) of Section 22-40 of this Code.
35 ILCS 200/21-225