Attenuation of trace elements in coal fly ash leachates by surfactant-modified zeolite

► Fly ash contains environmentally available and leachable trace elements. ► Several unlined fly ash disposal sites pose environmental risk of contamination. ► SMZ was evaluated for its applicability as permeable reactive barrier (PRB). ► SMZ helped remove and retard anionic species of trace elements in leachate. ► SMZ could be used as a PRB for unlined fly ash disposal facilities.