Revolutionizing soil and waste treatment: MoS2 nanosheets turbocharge geopolymerization for eco-friendly remediation and self-cementation of arsenic-contaminated soils and municipal solid waste incineration fly ashes

In the face of escalating arsenic pollution and the mounting challenge of municipal solid waste incineration (MSWI) fly ashes, cutting-edge technology has emerged as a game-changer. By harnessing the power of MoS 2 nanosheets, a revolutionary approach to double-self-cementation has been unlocked, addressing the limitations of previous methods. Through heterogeneous adsorption, MoS 2 nanosheets bolstered the stability of the matrix, leading to a remarkable surge in compressive strengths and a substantial reduction in leaching toxicities of heavy metals. The compressive strengths of the cemented cubes increased as the dosage of nanosheets increased from 0.3 % to 2.4 %, with compressive strengths ranging from 24.34 to 34.21 MPa. The leaching toxicities of Zn, Cu, Cr, Cd, Pb, and As from the solidified matrix correspondingly decreased to 0.32, 0.21, 0.04, 0.01, 0.05, and 0.53 mg/L, respectively. The role played by nanosheets in inhibiting the release and transport of chloride species further underscored their pivotal contribution. Moreover, the study delved into the intricate mechanisms underlying the impact caused by nanoscale materials cementation and geopolymerization systems, shedding light on their dual function as solidification intensifiers and chemical stabilizers. The nanosheet-enhanced double-self process can be appropriately fitted by the JMAK model. The linear nuclei growth of gels controlled the solidification and geopolymerization of the precursor materials and the stabilization of HM contaminants. This groundbreaking research not only elucidates the transformative potential of MoS 2 nanosheets but also paves the way for a paradigm shift in the treatment of contaminated soils and waste materials.