Investigation on Pseudomonas aeruginosa PAO1-driven bioleaching behavior of heavy metals in a novel geopolymer synthesized from municipal solid waste incineration bottom ash

This study synthesized a novel geopolymer utilizing 20% incineration bottom ash (IBA) by metakaolin replacement in the mix matrix, then conducted heavy metal bioleaching tests using Pseudomonas aeruginosa PAO1 (environmental bacterium). The findings showed bacterial interactions with geopolymers noticeably enhanced bioleaching, nevertheless, physicochemical processes involved in geopolymer formation significantly reduced bioleaching rate (14-100%) of several toxic elements (Cu, As, Pb and Cr). The metals possibly physically/chemically immobilized in geopolymer matrix. Chemical (SAM-HCl) dissolution confirmed geopolymer formation, while FE-SEM displayed distinct morphology between metakaolin- and IBA-based geopolymers. This research suggests IBA/similar wastes could be recycled for environmentally friendly geopolymer production. (C) 2020 Elsevier Ltd. All rights reserved.