Disclosed are absorbent structures including fibers bound with a polyvalent cation-containing compound and superabsorbent polymer particles. The fibers exhibit an ion extraction factor of at least 5 %. Also disclosed are multi-strata absorbent structures, such as disposable absorbent articles, including the treated fibers and SAP particles. Further disclosed are methods for preparing absorbent structures including the treated fibers; structures including fibers combined with a polyvalent cation-containing compound; and methods for treating or coating SAP particles with polyvalent cation-containing compounds.