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Municipal solid waste incinerator (MSWI) bottom ash (BA) was converted to zeolitic-type adsorbent materials by hydrothermal conversion under strongly alkaline conditions. The conversion product was determined to be a mixture of sodium aluminum silicate hydrate (SASH) (Na₂O·Al₂O₃·1.68SiO₂·1.73H₂O) and tobermorite (Ca₅Si₆O₁₆(OH)₂·4H₂O). The BET specific surface area was 22.1m²/g, which represented a significant gain compared to the BA (4.6m²/g) due to the formation of micropores and mesopores. The converted BA demonstrated promising performance for application as a sorbent towards several heavy metals (oxyanions of As(V), and Cd²⁺, Co²⁺, Ni²⁺, Pb²⁺, and Zn²⁺). Its performance was found to be generally superior to that of a mainly clinoptilolite natural zeolite, achieving greater sorption extents and better stabilizing capability of contaminated sediments. At a lower dosage rate (50mg …