Conversion of municipal solid waste incineration bottom ash to sorbent material for pollutants removal from water

Low cost and abundant municipal solid waste incineration bottom ash (IBA) was used as the feed material for the production of sorbents under alkaline hydrothermal conditions. The IBA-converted products were subsequently evaluated as adsorbents for pollutants (organic dyes and heavy metal ions) removal from water. The main mineral phases, quartz and calcite, in the raw IBA were transformed to zeolite, sodium aluminum silicon phosphorus oxide hydrate, katoite, and potassium aluminum silicate hydrate after conversion. The converted products showed a sheet-like microstructure with diameters ranging from 100 to 500 nm. The change in the mineral phase and morphology evolution of IBA significantly increased the specific surface area from 5.2 m² g^-1 to 45.1 m² g^-1 after conversion. It was found that the IBA-converted sorbents were efficient for the adsorption of basic dye (methylene blue) and heavy metal ions (Pb²⁺, Cd²⁺, Cu²⁺). The adsorption process was chemisorption in nature, and the kinetic experimental data followed the pseudo-second-order kinetic model. The conversion of IBA to sorbents provides a promising solution to both the sustainability of waste incineration and water contamination.